Part II - Extended Abstracts Posters

Reclamation of river-affected areas through agroforestry in Nepal

Shesh Kanta Kafle^[14]

Key words: inter-cropping, land degradation, plant diversity, silvipasture, weed infestation,

Introduction

More than 300,000 ha. of land have been damaged by rivers in Nepal (LRMP 1986). The extent and severity of damages have increased year after year due to the frequent changing nature of mountain rivers. Nepal's rivers carry around 336 million tons of soil per year to main river systems entering India (Brown 1981). The bed level of Terai rivers is rising by 35-45 cm annually (Dent 1984). The productivity of riverside lands has been seriously affected by silting, flooding deposition of pebbles and the like. In addition, natural succession in these areas has been inhibited by excessive grazing pressure as well as flash floods during the monsoon.

Among the many approaches to restore degraded land, agroforestry is often considered to be the most suitable strategy. Singh et al. (1994) have stated that agroforestry has much to offer in checking land degradation trends on one hand and in providing much needed products viz. food, fiber, fodder, fuelwood, timber, medicines etc. on the other.

A number of agroforestry practices have been launched in the midhills region of Nepal with the twin objectives of countering problems of land degradation and the meeting the demands of local people for fuelwood, fooder and small timber. This study looks at the effectiveness of such activities in reclaiming the rivers damaged areas of the midhills region.

The specific objectives of the study were:

To compare the growth performance of trees between river affected and unaffected areas.

To analyse crop production and identify the effectiveness of agroforestry practices in river-damaged areas.

Materials and methods

Study area

The study area is situated in a sub-tropical region on the eastern bank of the Adhikhola river in Syangja district of midhills region, Nepal. It is 32 kilometers south west of Syangja bazaar, the district headquarters, and lies at an altitude of 500 m above msl. The annual average rainfall is 1462 mm, most of which falls between May and September. Temperature ranges from 14.3^oc to 26.2^oC.

Land type classification

Based on the existing land type situation, the study area was categorized into three land type categorizes viz. land type A (LTA), land type B (LTB) and land type C (LTC). LTA includes the area affected by the river in the past with little chance of getting affected again. This area lies farthest from the river bank and is dominated by sandy soils with very low soil moisture content. Imperata cylinderica, Saccharum munja and Cassia occidentalis are the dominant plants found in the area. LTB involves the area affected by flash bloods during monsoon that remains dry for the rest of the period. This is the lower area than the LTA and has higher soil moisture content. Soil in this area is dominated by sandy clay, however, there were boulders and pebbles in the lower portion. Imperata cylinderica was the dominant ground flora, which is very difficult to uproot even in the summer season. LTC includes the area, which remains under water during monsoon. This area largely consists of rocks, stones, pebbles and sands. There was no vegetation cover in this zone and is difficult even to grow trees.

Agro-forestry designs

Major agroforestry designs practiced in the study area include: Agrisilviculture (Single crop, double crop and multi tree-crop inter-cropping) silvipasture and farm forestry blocks (Table 1)

Table 1. Agroforestry models practiced in the area.

Data collection and analysis

Vegetation establishment, land productivity and control of weeds were the three parameters taken into consideration as the bases for land reclamation. For this, growth performance of trees as well as production of agricultural crops were measured, and analysed using SPSS computer program. There were altogether 33 households directly involved in agroforestry activities. Therefore, an observation of all 33 direct beneficiaries was done.

Results and discussion

Growth performance of trees

Growth and mortality of tree plantings of four species were recorded (Table 2). The growth perofrmance of D. Sissoo was the highest among the four. Moreover, Dalbergia sissoo under different schemes (Table 3) shows that LTA-inter-cropping is the most suitable scheme for seedling growth.

The growth performance of tree seedlings in the 'block plantation' was slightly lower than the two other schemes. This was due to higher seedling density. Among the four species, Tectona grandis was found to have poorest growth performance moreover, there was no significant (a=0.05) difference in the height growth of Dalbergia sissoo planted in the river affected area and the unaffected (Table 3)

Table 2. Average growth of species in blocks after two growing seasons.

Values are mean ± SD

Table 3. Growth of Dalbergia sissoo under different.

Agriculture crop yield

Several agricultural crops were inter-cropped with D. sissoo at the tree spacing of 2.5×10 m. They included: maize, millet, potato, pigeon pea, oil seed (sesame), and bean. These crops were planted on the same plot at different seasons of the year. The maize production was 19.2 qtl./ha, which was quite good if compared to its production from the usual agricultural land, which is 24.57 qtl./ha (Table 4). However, the crop yield decreases on the canopy cover increases (Kafle 1994).

Table 3. Yield from agricultural crops

Effect of agroforestry practices on weeds

The presence of Imperata cylinderica and Saccharum munja grasses has made soil preparation for agricultural practices costly. These regarded among the world's worst grass species which acidify and further degrade the soil. However, these species are suitable for protecting soils from erosion and for cattle feeding. In the inter-cropping area, power tiller was used in order to prepare the land for cropping for the first time and local wooden ploughs were used afterwards. In such areas, the imperata grass was completely eradicated. In the silvipasture blocks, where D. sissoo and A. catechu were planted at a spacing of 5×5m, the composition of grass species was noticed to have changed. New species appeared such as Phaspalum sp., Phragmites sp. and Seteria sp. were more palatable to cattle. After protecting the area from grazing, Cassia occidentalis was seen to have disappeared. Where as in block plantation area, growth of Imperata cylinderica and Saccharum munja was completely stunted. Most probably, it was due to shading. Also the growth of grass species was seen to have prevented during second rainy season.

Conclusions

Agroforestry systems especially D. sissoo inter-cropped with the local agricultural crops such as beans, finger millet, pigeon pea, maize and potato are suitable for land reclamation. Block plantation of various MPTS is also useful, however, farmers prefer planting D. sissoo along with agriculture crops instead of planting trees alone. Protecting grasslands and planting D.sissoo and A. catechu result in a change in the vegetation composition leading to increased plant diversity.

References

Brown, L.R. (1981) The global loss of top soil. J. Soil and water conservation36:255-260

Kafle, S.K. (1994) Environmental impact of farm forestry Activities: A case from Chitwan, Nepal. In Panjab Singh, PS Pathak, and M.M. Roy (Eds.) Agroforestry systems for sustainable land use, Oxford & IBH , PP 185-195.

LRMP (1986) Forestry land use report, Topographical survey branch, Kathmandu.

Dent F.R. (1984) land degradation: present status, training and education needs in Asia and Pacific. UNEP, Banglore.

Restoration of degraded pasture lands with forest plantations and Canavalia ensiformes

Carlos Enrique Aguirre^[15], Morena Raquel Mangandi Ramos^[16],
Rolando Henríquez Salgado^[17], Javier Magana^[18]

Introduction

In the Cooperative El Platanar (department of San Miguel, El Salvador), the land has been severely degraded by inappropriate cattle management (high densities, uncontrolled grazing) and the extensive use of fertilizers and pesticides in the production of Henequén (Agave letonae). In order to restore the degraded pasture lands present in the Cooperative, a reforestation and soil conservation program was started in 1997. This program planted more than 200 mz with native tree species and also constructed roughly 11,000 linear meters of ditches with live barriers of gandul (Cajanus cajan) and Zacate Limón (Cymbopogon citratus). Most of the trees were planted directly into the degraded pastures; however in a subset of the area (6 Mz) the trees were planted in association with Frijol Abono (Canavalia ensiformes), to determine whether the presence of Canavalia would benefit tree growth and improve soil conditions.

The objective of this study was to evaluate and compare the growth of the forest species in the degraded pastures and to evaluate the effect on Canavalia on soil conditions, and tree growth and development.

Methods

The study was conducted within the 200 Mz plantation (known as “La Coyota”) located within the Cooperative El Platanar, in the municipality of Moncagua, department of San Miguel en El Salvador. The area is characterized by steep slopes (40-50%) of moderate pedregosity and has latosol and litosol soils. The elevation is 490 m.a.s.l; maximum temperatures in the dry season are above 39 C and average annual rainfall is less than 1400 mm. The dry and wet seasons are very pronounced, each lasting six months.

The local population dedicates itself mainly to production of maize (for family consumption), but roughly half of the farmers also work for the Cooperative El Platanar that produces fiber from Henequén.

The forest trees were planted in February, 1997 in a degraded pasture that had been grazed for roughly 5 years. Prior to that the area had been planted with Henequen. Within a 200 Mz area, a variety of tree species were planted, using seeds of carefully selected mother trees: Ceiba (Ceiba pentandra) , Madrecacao (Gliricidia sepium), Laurel (Cordia alliodora), San Andrés (Tecoma stans), Paraiso (Melia azerdach) and Marañón (Anacardium occidentalis). The trees were planted at a distance of 3 X 3 m (density of 622 trees/Mz), and were fertilized by applying 2 lbs of an organic fertilizer, elaborated from the residue from the processing of Henequen, cow dung, ash, soil and water. The site contained many trees of “Pie de Venado” (Bauhinia ungulata; roughly 3000 sprouts/Mz) that had naturally regenerated in the site and these trees were freed of weeds to facilitate their growth. The reforested areas were also protected against erosion by constructing ditches and using live fences of Cajunus cajan. Since their establishment, the plantations have been regularly weeded and fertilized using organic fertilizer.

In June of 1998, a subsection of the original plantation (6 mz) was planted with frijol de abono (Canavalia ensiformes) in order to increase nutrient availability in the soil and possibly promote tree growth. Canavalia was planted at a distance of 0.8 m between plants and 1.0 m between rows, among the forest trees already present.

In order to compare the growth and development of the tree species within the degraded pastures, we measured the dap and height of 40 randomly selected individuals of each species. For those species present in both the areas with or without Canavalia, an additional 30 trees were measured within the area planted with Canavalia. In addition, all trees were examined for signs of disease and growth form defects.

To evaluate the preliminary effect of Canavalia on soil properties, soil analyses were taken both within and outside of the area sown with Canavalia, and were examined for organic material, humidity, N, P, K, texture and pH. Soil analyses were also taken before the Canavalia was planted and at the end of its growth. In addition, data were collected on the production of biomass and the percent cover within the Canavalia plantation.

To evaluate the preliminary effect of the Canavalia on the growth of forest trees (Gliricidia sepium, Tecoma stans and Anacardium occidentalis) the heights and diameters of the trees within the planted area (30 per species) were compared with those of trees planted in areas that had no Canavalia (40 trees per species).

Local farmers who had participated in the establishment and management of the forest plantations were also asked their opinions of the performance of the different forest trees in the site and the use of Canavalia, in order to document local acceptance of these technologies.

Results and discussion

The growth of the forest trees varied greatly among species, with some species reaching mean heights of nearly 4 m(within 3 years) and other reaching less than 2 m (Table 1). Of the tree species planted, Gliricidia sepium and Tecoma stans had the highest growth rates, while Paraiso and Caoba grew the slowest.

Table 1. Diameters and heights of trees planted in degraded pastures (with Canavalia), at 36 months.

The presence of the Canavalia within the forest tree plantations appears to have slightly increased the growth of Gliricidia sepium, Anacardium occidentalis and Tecoma stans (Table 2). All three of these species had slightly higher diameters and heights when grown in association with Canavalia, suggesting that the presence of Canavalia may help increase tree growth.

Table 2. The effect of Canavalia ensiformes on tree growth and height on 3 forest tree species (n=30 trees/species for trees with Canavalia; n= 40 trees/species for those without Canavalia).

Although these data are preliminary, they suggest that the establishment of forest plantations on degraded pasture lands may be aided, at least partly, by the establishment of Canavalia in the understory.

A comparison of two methods for the establishment of a silvopastoral system om degraded pasture land

Margarida M. Carvalho^[19], Carlos Renato T. Castro^[20], Luiz Carlos T. Yamaguchi^[21],
Maurílio J. Alvim^[22], Ben Hur A. Rocha Filho^[23], Rui da Silva Verneque^[24]

Key words: legume trees, nitrogen, pasture degradation, rehabilitation

Introduction

In the mountainous area of southeast Brazil, two major constraints for the development of the degraded pasture land are: i) the main soils are very acid and infertile; ii) soil mechanization, for pasture sowing, is difficult and may enhance erosion, with loss of the surface soil, which is the most fertile.

The low fertility of the main soils, particularly of the red-yellow latosol (oxisol), and the low carrying capacity of the naturalized molasses-grass (Melinis minutiflora) has led to its substitution for the more aggressive and higher yielding species of the genus Brachiaria. However, to be successful, the Brachiaria species establishment depend on the application of phosphorus fertilizers and on the use of a soil preparation method, not conducive to soil erosion (Carvalho, 1998). In addition, the long term productivity of the sown grass pastures in these areas depend on the availability of a nitrogen source.

The silvopastoral systems appear as a viable option to develop the degraded pasture land which predominate in the region, due to its potential for soil fertility improvement and land stabilization, among other advantages to animal production systems.

Two methods of establishment of a silvopastoral system designed to resolve the problems arisen, are compared, emphasizing the time required for the establishment and the budget necessary for the establishment phase.

Materials and methods

The experiment was undertaken at the Coronel Pacheco Field Station, which belongs to Embrapa Dairy Cattle Research Center, and located in the southeastern region of Minas Gerais State, Brazil. The site was a degraded molasses-grass pasture, with declivity around 30%, and the soil is a red-yellow latosol (oxisol), with the following chemical characteristics before sowing: pH in water, 4.61; available P (Mehlich), 4.47 mg/dm³; exchangeable bases (cmol_c/dm³): K, 0.11; Ca, 0.33; Mg, 0.12; Al, 0.79.

Characteristics of the proposed silvopastoral system are as follows: trees are planted in 10 m wide strips, with four rows, prepared across the slope and separated by 30 m wide strips, for the herbaceous forages. Treatments compared were two methods of protecting tree strips: 1) Strip protection with wire fences; 2) Without protection, but without grazing. In addition, two different combinations of tree species in the strips were compared: a) Eucalyptus grandis and Acacia mangium, spaced 3 m x 4 m, total of 100 trees/ha of each species. b) Eucalyptus grandis, Acacia mangium, spaced 3 m x 6 m, total of 68 trees/ha of each species; Mimosa artemisiana, Acacia angustissima and a hybrid Leucaena leucocephala x L. diversifolia, spaced 3 m x 3 m, total of 42 trees/ha of each species. The main objective of the present paper is the comparison of the tree protection treatments.

Treatments were allocated in 5,000 m² plots, with two replications. The experiment was planted during the period from November to December 1997. In treatments with tree protection, the tree seedlings and the herbaceous forages were planted simultaneously. In treatments without tree protection, the tree seedlings were planted in 1997, and, in the 30 m wide strips, pigeon pea (Cajanus cajan) was sown, aiming at improving soil fertility. In November-December 1998, maize plus the herbaceous forages were sown after soil incorporation of pigeon pea.

The herbaceous forage species used were: Brachiaria decumbens and Stylosanthes guianensis var. vulgaris cv. Mineirão. In the 30 m wide strip soil preparation for sowing of these species was done in strips, across the slope, according to Cruz Filho et al. (1986). Liming and fertilizers application were performed prior to sowing, based on previous research results, using the following sources and rates: dolomitic limestone, 1,000 kg/ha; Araxá rock phosphate, 600 kg/ha; single superphosphate, 250 kg/ha; KCl, 100 kg/ha and fritted trace elements (FTE Br-16), 30 kg/ha.

Tree seedlings were planted in pits and fertilized with (g/pit): a) eucalypt, dolomitic limestone, 50; ammonium sulfate, 75; single superphosphate, 225 and KCl, 15. b) legumes, dolomitic limestone, 50; Araxá rock phosphate, 80, single superphosphate, 100, KCl, 25 and FTE Br-16, 10. In January 1998 the tree seedlings were fertilized again with (g/plant): a) eucalypt, ammonium sulfate, 30; single superphosphate, 50 and KCl, 15. b) legumes, single superphosphate, 30 and KCl, 10.

For the evaluation of the establishment methods, two main parameters were considered: tree height and budget necessary for the establishment phase. Tree height was measured every four months, in four rows per plot. The mean of a species in each row per plot was used as replication in the analysis of variance. Prices of all items (seeds, tree seedlings, fertilizers, fences) and of labor used, were recorded to calculate the budget. Besides, the calculated income relative to liveweight gains (with tree protection treatment) and maize yield (without tree protection), were used to discount from the total budget necessary to each treatment.

Results

Tree growth was not significantly affected (P>0.05) by the method of protecting tree strips in any period of height measurement. However, tree height was always affected (P<0.05) by species combination, the average height of the two species (Combination “a”) being higher than that of the five species (Combination “b”). Significant differences among species were observed in tree combination “b” (Table 1). The species M. artemisiana and the Leucaena hybrid reached lower height than the other three species. A separated analysis of variance, performed with data of E. grandis and A. mangium, indicated that the average height of the two species did not differ significantly, but were higher (P<0.05) in combination “a” than in combination “b” in all periods of evaluation.

Table 1. Average height (m) of five tree species, in three periods and under two species combination schemes.

¹ Numbers in brackets indicate months after tree seedlings planting.

² Tree combination 1 = E. grandis + A. mangium; Tree combination 2 = all five species.

³ Means in the columns followed by the same letters do not differ significantly by Newman-Keuls test.

The initial budget required for the establishment of the trees and the pasture amounted in US$ 738.61 for method 1 and US$ 515.89 for method 2 (Table 2). Thus, the initial budget was 64.89% higher in method 1 than in method 2, due to the expenditure with preparation of fences to protect the trees in method 1. Discounting the net income obtained through animal gains in method 1, and with maize yield in method 2, the total budget necessary for the establishment of one hectare of silvopastoral system, in a period of two years were US$ 582.68 and US$ 434.02 for methods 1 and 2, respectively.

Table 2. Budget required for the establishment of a silvopastoral system in a degraded pasture land, under two methods of tree protection.

Discussion

In method 1, the establishment of the B. decumbens x S. guianensis pasture was completed three months after sowing. In this treatment, grazing started in April/98, when trees were too small to support animal damage, thus requiring protection.

By October/98, ten months after planting of the tree seedlings, the average height across the five species and treatments reached 1.94 m, and 14 months after planting, all species reached height over 2 m (Table 1). Thus, despite the high acidity and low soil fertility conditions prevailing, the fast growing legume trees used in the experiment, particularly A. mangium and A. angustissima, had a very good performance, as observed in a previous study (Carvalho et al, 1999). According to information for eucalypti (Silva et al., 1996), the minimum height of trees by the time of the first grazing, to avoid significant damage to the trees is 2.0 m. Therefore, the wire fences could be removed by March-April/99 and grazing extended to the whole area.

In method 2, maize was harvested in late April/99 and pasture establishment was delayed relative to method 1. Grazing in this treatment could start by October/99, when tree height (Table 1) was sufficient to avoid serious damage by grazing animals. Thus, in the establishment of the proposed silvopastoral system without tree protection (method 2) the first grazing will be delayed by about six months relative to method 1. However, the lower initial budget required will compensate for the late grazing. In more fertile soils, farmers will be able to grow a maize (or other) crop in the first year too, decreasing further the total budget necessary for the silvopastoral system establishment.

Conclusions

The total budget necessary for the establishment of a silvopastoral system in a degraded pasture land was lower when trees were not protected with wire fences than when they were protected. However, in the latter case, grazing the whole area of pasture can be advanced by about six months relative to the other method.

Using fast growing and adapted trees, the silvopastoral system will be established in 16 to 22 months depending on the method of tree protection.

References

Carvalho MM (1998) Recuperação de pastagens degradadas em áreas de relevo acidentado. In: Dias LE, Mello JWV ed. Recuperação de áreas degradadas. Viçosa: UFV, Departamento de Solos; Sociedade Brasileira de Recuperação de Áreas Degradadas, 251p., p. 149-161.

Carvalho MM, Freitas VP, Xavier DF (1999) Comportamento de cinco leguminosas arbóreas exóticas em pastagem formada em Latossolo Vermelho-Amarelo de baixa fertilidade. Rev. Árvore, 23: 187-192.

Cruz Filho AB, Cóser AC, Novelly PE (1986) Comparação entre métodos de plantio de Brachiaria decumbens em pastagens de capim-gordura em áreas montanhosas. Rev. Soc. Bras. Zoot. 15: 297-306.

Silva JLS, Garcia R, Saibro JC (1996) Desempenho de bovinos e seus efeitos sobre as árvores em florestas de eucalipto (Eucalyptus saligna) na região fisiográfica da Depressão Central no RS. In: SIMPÓSIO INTERNACIONAL SOBRE ECOSSISTEMAS FLORESTAIS, 4., 1996, Belo Horizonte. Belo Horizonte: Biosfera. p. 342-345.

Livestock grazing in forest by livestock dependent forest dwelling communities: A case study

Tanmay Samajdar^[25], Mahesh Chander^[26]

Key words : buffaloes, dairy husbandry, North India, participation, Van Gujjars

Introduction

Livestock grazing in forest is significant in developing countries including India. About 60% of the world’s pasture land, just less than half the world's usable surface is covered by grazing system, which supports 360 million cattle and over 600 million sheep and goats (Steinfeld et al., 1997). The diverse opinion on the impact and implication of such grazing is well documented. The majority of workers have indicated a very positive relationship between livestock and deforestation (Downing, et al., 1992; Pearce and Warford, 1993; Kaimowitz, 1996 and Teuscher, 1998), yet some consider positive impact of grazing on forest resources (Quarro, 1986; Faminow, 1998 and Kotiluoto, 1998). The Animal Health and Production division of FAO has taken a stand that the role of livestock as agents of environmental damage has often been misunderstood and consequently misrepresented. Even, the presence of livestock keeping forest dwelling communities are viewed by the forestry experts, economists and other agencies as a cause of forest depletion while anthropologists and ecologists have argued that the pastoralists have developed sustainable mode of pasture management based on sound knowledge of forest ecosystem (Bollig and Schulte,1999).The arguments in this regards including the relocation of such communities are manifold and well documented. One such community called Van Gujjars who solely live on animal husbandry inside the forest of North India was studied in order to assess the actual scenario.

Materials and methods

A case study with anthropological approach was conducted in Tanda forest range of Nainital district of Uttar Pradesh (now under newly created state named Uttranchal) in North India to study the animal husbandry practices of Van Gujjars.Three hamlets (Lalkuan,Dhimri and Tanda Gatter hamlets) were purposively selected for study due to availability of large number of Van Gujjars and easy access from the authors' institute. The data were collected by observation and questioning the key informants.

Results and discussion

Grass was a major source of feed for the animals. Grasses mainly Cynodon dactylon and Ischoemum angustifolium were available from April to September. Earlier, Van Gujjars used to maintain their animals on grazing alone but now-a-days, due to less availability of different kinds of grasses and restriction by the forest department, grazing has decreased considerably. Apart from the grasses, some of the important fodder trees lopped by Van Gujjars are Acacia catechu, Trewia nudiflora, Albizzia procera, Mitragyna parvifolia, Kydia calycina, Ficus religiosa, Toona ciliata, Adina cordifolia, Ficus glomerata and Stereospermum suaveolens.These trees are otherwise not popular among non Van Gujjars as fodder trees but Van Gujjars attach good importance to these trees. As such, these fodder trees once found nutritively valuable (through laboratory tests) may be suitably improved through genetic interventions for introduction into the agroforestry systems to supplement the fodder to meet the feed and fodder scarcity situations prevailing in most of the developing countries. The feeding particularly grazing and lopping is important aspect of livestock rearing by Van Gujjars since it makes the whole system a unique one wherein livestock are reared almost totally on forest resources.

The average duration of grazing was found to be 14 to 16 hours per day. Van Gujjars follow rotational grazing. They comeback to the grazing area when the grasses in that area are regenerated. Their traditional wisdom in this regard was quite important from the stand point of natural resource management and sustainability of Common Property Resources (CPRs). Whereas, when the grazing is uncontrolled it causes denudation of soil, destruction of vegetation and tree saplings, dissemination of animal diseases, unrestricted movement of livestock and other social problems such as conflicts with the farmers (Okaeme et al., 1998).Moreover, they continuously exploit the forest resources without contributing towards forest conservation and management. Only they pay grazing tax to the forest department at the rates given below:

Upto 10 animals : Rs. 8 or 0.18$ per year
Upto 20 animals : Rs. 10 or 0.22$ per year
Upto 30 animals : Rs. 16 or 0.36$ per year
Upto 40 animals Rs. 20 or 0.44$ per year
Above 40 animals : Rs 56 or 1.24$ per year.

The meagre tax paid to the forest department was not a deterrrant to the Van Gujjars. Moreover, inputs being almost free, any amount of earning from livestock was bonus to the Van Gujjars, hence, a large number of livestock were maintained by each family. These families were not bound by any formal arrangement towards forest protection, forest management, afforestation etc.

Of late, this community owing to the reported adverse impact on forest is pressurized by the government to evacuate the forest where they had been living since centuries and to be relocated outside the forest where they have to make lots of adjustment against their will. Eventually, the relocated people are forced to give up their independent and dignified lives and end up as exploited and alienated communities (Rao and Geisler, 1990).As such, relocation does not seem to be an answer to solve the problem of forest and forest dwelling communities.

Conclusion

Van Gujjars should be made responsible towards afforestation, maintenance of forest, etc. through the arrangement like Forest Committee, Joint Forest Management (JFM) so as to secure participation of this community in forest management. Since, the relocation efforts for this community have so far not met with success, they should be allowed to stay inside the forest with proper education and training on appropriate grazing practices, and the mechanism need to be evolved wherein their effective participation is ensured towards sustainability and better productivity of forest along with the socio-economic and cultural well being of this indigenous livestock dependent forest dwelling community. There are several other similar communities in India as well as other developing countries who need to be properly educated and trained on sustainable natural resource management while drawing livelihood from the forest. The change in relationship from purely extractive to symbiotic is very much needed in such cases.

References

Bollig M and Schulte A (1999) Environmental change and pastoral perceptions : Degradation and indigenous knowledge in two African pastoral communities. Human Ecology 27(3) : 493-514.

Downing T, Hecht S, Pearson H and Downing C (eds) (1992) Development or destruction : The conversion of tropical forest to pasture in Latin America. Boulder, Westview Press.

Faminow MD (1998) Cattle deforestation and development in the Amazon :An economic, agronomic and environmental perspective. Oxford, CAB International.

Kaimowitz D (1996) Livestock and deforestation in Central America in the 1980s and 1990s : A policy perspective. Center for International Forestry Research, Jakarta.

Kotiluoto R (1998) Vegetation changes in restored seminatural meadows in the Turku Archipelago of SW Finland. Plant Ecology 136: 53-67.

Okaeme AN, Ayeni JSO, Wani M, Oyatogun MO, Haliru MM and Okeyoyin AO (1988) Cattle movement and its ecological implications in the middle Niger Valley area of Nigeria. Environmental Conservation 15(4): 311-319.

Pearce DW and Warford JJ (1993) Resource degradation : Cause and policy response. In: World without end. Washington DC, Oxford University Press pp. 7-20.

Quarro M (1986) Goats and forest ecosystems : Direction for research and development concerning pastoralism in Morocco, Fourages 106: 3-9.

Rao K and Geisler C (1990) The social consequences of Protected Areas development for resident population. Society and Natural Resources 3: 19-32.

Steinfeld H, Haan Cees de and Blackburn H (1997) Livestock environment interactions : A summary of global issues and options. Draft FAO, Rome.

Teuscher T (1998) Different effects of livestock farming systems on the environment. Entwichlung - + - landlicher-Raum 32(4): 13-16.

Role of animals in improved fallow management in the tropics

Donald L. Kass^[27], M. Ibrahim^[28], A Schlönvoigt^[29], O. Flores^[30], H.Perla^[31]

Key words: Chaco, matorral, organic fertilizers, P availability, scrub forest, tacotal

Introduction

The presence of animals in improved fallows can enhance almost all fallow functions: animals can enhance fertility restoration, weed suppression, and seed disperson of fallow species. Possible negative effects on soil structure can be overcome by controlling animal populations and by the frequently beneficial effects of fallow systems on soil physical properties.

Most fallow systems in Latin America include animals. Animals are frequently grazed on previously cropped areas during the dry season. The so-called “tacotal” which is fallow land used for animal grazing is an ubiquitous component of farms throughout Central America. Most areas in the wet-dry tropics of Latin America contain a similar component (Acahuales in Mexico, the Cerrado and Caatinga of Brazil, the Chaco of Argentina and Paraguay,the Espinales of Chile) (Kass and Somarriba, 1999). The animal component increases the quality of the fallow since animal manures generally contain phosphorus and calcium in more plant-available forms than the plant residues on which the animals fed (Satti et al., 1999; Arco-Verde et al., 1998). Organic compounds in animal manures also confer increased stability to soil organic matter , serve as an energy source for microbial activities, serve as precursors to soil organic matter, reduce phosphorus sorption by the soil and may be significant in binding toxic substances such as aluminum in non-plant available forms (Flores et al., 1999). It has been pointed out that the major land use in Central America and Mexico is now unimproved pasture consisting of poor quality grasses and small trees of varying nutritional value (Greenberg et al., 1997) used for extensive cattle grazing. Buckels and Triomphe (1999) state that the major challenge to the frijol abono system of producing maize in Northern Honduras is the conversion of land to pasture. They also point out that the pasture land is often rotated with crop production for brief periods. Fortunately, there is a rich asortment of trees and shrubs available that can contribute to both cattle feeding and long-term soil improvement. A sustainable system has been developed in Panama in which Canavalia ensiformis is sown into maize and then enriches the maize stover which is grazed in the ensuing dry season, permitting a repetition of the maize crop in the next wet season (Gordón et al., 1995).

In many areas of Africa and Asia, land is too scarce for long fallows.Cattle may wander over previously cropped areas and eat crop residues or receive feeding supplements from protein banks, line-plantings, or hedgerows (Paterson et al., 1998). In many parts of Africa, cropping and livestock husbandry and ethnically and operationally separate enterprises (Powell and Mohammed-Saleem, 1987). Where efforts have been made to incorporate grazed fallows into the production system, effects on crop yield have generally been positive (Powell and Mohammed-Saleem, 1987).

Pathways of increased N and P Availability

Most of the work on plant residues has concentrated on organic matter breakdown and nitrogen release. Lupawyi and Haque (1998) report that four accessions of Sesbania species and two accessions of Leucaena species were significant sources of N, K, and Mg but insignificant sources of P and Ca in an incubation study. Not all Leucaena species release significant amounts of N during the incubation period (Lupawyi and Haque, 1998). The only effective organic sources of Ca and P to succeeding crops would appear to be animal manures (Arco-Verde et al., 1998) . Jama et al. (1997) report greater financial benefits from a maize-calliandra system at P-deficient sites in western Kenya when the leaf biomass of Calliandra was fed to dairy cattle as a protein supplement and resulting cattle manure was returned to maize than when leaf biomass was directly applied to maize. It is generally felt that plant residues must contain more than 2.4 g kg^-1 of phosphorus to increase plant available P in soil (Buresh, 1999). Of 9 woody species screened in Kenya (Calliandra calothyrsus Meisn., Croton meglocarpus, Dactylandenia barteri, Gliricidia sepium (Jacq.) Walp., Lantana camara, Leucaena leucocephala (Lam.) de Wit., Senna spectabilis, Sesbania sesban, and Tithonia diversifolia), only three (C. megalocarpus, L.camara, and T. diversifolia) are found to have the threshhold P content (Palm et al., 1999).

Because of the materials contained in conventional rations and some peculiarities in their physiology, chicken manure has frequently been shown superior to other animal manure in cropping trials (Arco-Verde et al., 1999). Because of their limited ability to assimilate P, chicken are generally fed rations with high P content resulting in high P levels in the manure. Similarly, Ca levels are increased when egg production is the chief objective. The nutrient content of the manures reflects these differences. Feeding chickens from agroforestry systems has been little studied but offers a promising way of reducing imports of feedstuffs.

Kass et al. (1999) report significant increases of readily available P fractions (extracted with resins and bicarbonate) when cattle manure was used as the only P source for maize and beans in a twelve-year experiment in Turrialba, Costa Rica. Levels of readily available P are higher in the manure treatment without added P than in the treatments where mineral P was added yearly for ten years. Addition of Erythrina leaves has a smaller effect on P fractions. Addition of mineral phosphorus has a greater effect on less readily available (hydroxide extracted) P fractions (Kass et al., 1999). More recent research has shown even more striking effects on available P fractions from the addition of chicken manure and lime. Unlike phosphate rock for which no source has yet been found in Central America, limestone is extremely abundant in the region since the greater part of Central America was a shallow sea until 2-3 million years ago (Coates, 1997). Until native sources of rock phosphate are located in Central America, use of phosphate rock to increase the P availablility of organic amendments (Tian and Kolawole, 1999) is not a viable option. Furthermore, results of adding phosphate rock to plant residues were inconsistent and were not effective on all soil types (Tian and Kolawole, 1999).

Following the application of various organic amendments including a mucuna fallow to an extremely infertile Acrudoxic Melanudand with very high P retention characteristics yield of dry beans and snapbeans as well as P levels in various fractions was determined. Although resin P was only significantly increased by the application of chicken manure, inorganic bicarbonate extracted P which according to Tiessen et al. (1984) also forms part of the most plant available inorganic phosphorus, was significantly increased over the control in all treatments receiving organic amendments including a rotation with a mucuna fallow which should have supplied insignificant amounts of external P (Kass et al., 1999). The only external P supplied by the Mucuna fallow could have come from the seeds and could not have amounted to more than 1-2 kg/ha P, while the increase in bicarbonate extracted P from the mucuna fallow was more than 5 mg kg-1 P which would correspond to about 3.5 kg ha-1 P since the soil had a bulk density of 0.7 t m-3. Although lower than the control, the organic bicarbonate P fraction which, according to Bowman and Cole (1978) is readily mineralizable and contributes to plant available P, was higher in the mucuna treatment than with the chicken manure. So, we have considerable evidence that the mucuna fallow is contributing by making considerable amounts of otherwise unavailable soil P available to succeeding crops. These results may support the hypothesis that in the absence of animals, fallow materials function to increase P supply to succeeding crops principally by blocking sorption sites in soils.

Liming only consistently increased the Resin P fraction and increased bean yield in all cases except where chicken manure was applied. Although the highest bean yields in both 1999 and 2000 were obtained with chicken manure , the combinations of liming and chicken manure seemed to increase some of the recalcitrant.

P fractions (inorganic NaOH extractable P and reisdual P) especially at the higher chicken manure rates. In the case of mucuna, the only P fraction to be increased by liming was the resin P. As bean yields were sharply increased by liming, one must conclude that only the resin P is signficantly exploited by the bean crop or that calcium and magnesium deficiency were more significant than phosphorus deficiency in this soil.

Conclusions

There is a need to develop practical systems adapted to different ecological conditions. Several woody and non-woody fallow species are available but their comparative advantages are often poorly characterized. Some of these species also have insecticidal and other antagonistic properties which can be of value in organic and low-input production systems (Paterson et al., 1998). A collaborative project with Tithonia diversifolia sponsored by DFID and the University of Wales has shown that valuable fallow species need not be confined to the Leguminosae. The organic compounds which may be functioning in blockage of P sorption sites should be characterized so that breeding programs can screen for them (Lowell, 2000). With proper choice of both plant and animal species and good management practices, managed fallows with animals could be an important source of nutrients as well as a means of weed control for crop production in the tropics. They could also function to maintain biodiversity of both temperate and tropical species (Greenberg et al., 1997).

Acknowledgement

Funds for the P fractionations reported here were supplied by the Cornell University International Institute for Food, Agriculture, and Development (CIIFAD).

References

Arco-Verde, M., Kass, D.L., Muschler, R., Ibrahim, M.,Fernandes, E.C. 1999. Capacity of nitrogen-fixing trees to supply nutrients to maize on a base-deficientsoil of Costa Rica. Actas de la IV Semana Cientifica, CATIE. 179-184.

Bowman, R.A. and Cole, C.V. 1978. An exploratory method for fractionation Of phosphorus from grassland soils. Soil Science 125: 95-101

Buckles, D. and Triomphe, B. 1999. Adoption of mucuna in the farming systems of northern Honduras. Agroforestry Systems 47: 67-91..

Buresh, R.J. 1999. Phosphorus management in tropical agroforestry: current knowledge and research challenges. Agroforestry Forum 9(4): 61-66.

Coates, A. G. 1997. The forging of Central America. In Coates, A.G. eds. Central America, a natural and cultural history, p. 1-37. Yale University Press. New Haven, USA.

Flores, O, Ibrahim M., Kass, D. and Andrade, H. 1999. El efecto de los taninos de especies forrajeras sobre la utilización de nitrógeno por bovinos. Agroforestería en las Américas.6(23):42-44.

Gordón, R., Franco, A., de Herrera, N., González, A, and Herrera, D. Siembra de maíz en rotación con Canavalia. Panama. Instituto de Investigación Agropecuária de Panama (IDIAP), Panama City, Panama, 6 pp.

Greenberg, R. Bichier, P. and Sterling, J. 1997. Acacia, cattle and migratory birds in southeastern Mexico . Biological Conservation 80: 235-247.

Jama, B., Swinkels, R.A., and Buresh, R.J. 1997. Agronomic and economic evaluation of Organic and inorganic sources of phosphorus in western Kenya. Agronomy Journal 89: 597/604.

Kass, D.C.L. and Somarriba, E. 1999. Traditional fallows in Latin America. Agroforestry Systems 47: 13-36

Kass, D.C.L., Somarrriba, E., and Vasconcelos de Macêdo. 1999. Effect of sampling time and depth on P fractions in agroforestry systems. Agroforestry Forum. 9(4): 42-49. Morillton, USA.

Lupwayi, N.Z. and Haque, I. Mineralization of N, P, K, Ca, and Mg from Sesbania and Leucaena leaves varying in chemical composition. Soil Biol. Biochem. 30: 337-343.

Palm, C., Nziguheba, G., Gachengo, C., Gacheru, E. and Rao, M.R. 1999. Organic materials as sources of phosphorus. Agroforesty Forum 9(4): 30-33

Powell, J.M. and Mohamed-Saleem, M.A. 1987. Nitrogen and phosphorus Transfers in a crop-livestock system in West Africa. Agricultural Systems 25: 261-277.

Paterson, R.T., Karanja, G.M., Roothaert, O.Z., Nyaata, L.Z, and Kariuki, I.W. 1998. A review of tree fodder production and utilization within smallholder agroforestry systems in Kenya. Agroforestry Systems 41: 181-199.

Satti, P., Mazzarino, M.J. y Laos, F. 1999. Relación entre fracciones de fósforo en enmiendas orgánicas y disponibilidad en suelos volcánicos. Congresso Latinoamericano de Ciencias de Suelo. Santiago, Chile.

Tian , G. and Kolawole, G.O. 1999. Phosphorus availability of phosphate rock incubated with plant residues with various chemical compositions. Agroforestry Forum 9(4): 40-42.

Tiessen, H., Stewart, J.W.B, and Cole, C.V. 1984. Pathways of phosphorus transformations in soils of differing pedogenesis. Soil Science Soc Amer. J. 48: 853-858

Tiessen, H., Salcedo, I.H., and Sampaio, E.S.V.B. 1992. Nutrient and soil organic matter dynamics under shifting cultivation in semi-arid Northeastern Brazil. Agriculture, Ecosystems an Environment 38: 139-151

Sustainable production of natural resources and management of ecosystems: the potential of South American Camelid breeding in the Andean Region.

(SUPREME)

Sebastiano Vinella^[32], Maria Rosa Virdis^[33], Marco Antonini^[34], Massimo Iannetta^[35]

Key words: animal breeding, dryland ecosystems, environmental impacts, regional economics, rural development.

Objectives

The EU-funded RTD project SUPREME was set up in 1996 to assess the potential of South American Camelid breeding in the Andean region. It seeks to assist in developing the production chain of fibre and meat from Llama and Alpaca, capable of reconciling conservation and sustainable use of natural resources of Andean Altiplano with the improvement of quality of life in rural communities.

The specific objectives focused on:

A. Identification of regional policies of sustainable development connected to the productive use of Llama and Alpaca.

B. Definition of an institutional and social approach to ecosystem management in homogeneous areas of Llama and Alpaca production.

C. Identification of resource management methods and operative tools, aimed at strengthening the potential of Llama and Alpaca production chain, from the pastures and stock-breeding to the manufacturing and trade of fibre and meat.

D. Integration of the RTD activities carried out with those ongoing in the Andean region for the purpose of fostering development and economic co-operation among the Latin-American countries considered and between them and the European Community.

Activities

The SUPREME project was broken down into Work-packages, three of which covered the main research aspects considered by the specific objectives:

Work-package A: Relationship between the environment and economic activities

The goals of this research package were to provide an information framework concerning the various factors affecting the environment of Camelids production areas of Andean Altiplano and to set up a management methodology of these factors.

The aim was to support the development of policies of sustainable management of natural resources and to propose pasture improvement measures to strengthen Camelids breeding.

Work-package B: Economic and social development issues

The goals of this research package were: to analyse the policy, socio-economic and cultural factors affecting the Camelid-breeding activities and the management of natural resources in the region of the Andean Altiplano; to define the conditions for a viable and sustainable development strategy for the Camelid production chain in the region.

Work-package C: Relationship between sustainable development and improvement of Camelids production

The identification of management methods and operative tools concerning Camelids breeding improvement and products qualification able to strengthen the Camelids production chain represented the main goals of this Work-package.

In addiction two Work-packages concerned the project management:

Work-package D: Exchange of information/experience

Work-package E: Co-ordination and evaluation

The research activity has been carried out in the following geographic areas:

• In Argentina, in the portion of the “Altiplano” included in the Jujuy Province for field activities and in sites outside the “ Altiplano ” (central area of the “Pampa”), at private operators farms, for the activities in experimental sites.

• In Bolivia, in the Sajama national park (Department of La Paz), in parts of the Central Andean highland and in Patacamaya (at IBTA experimental station) for the activities in experimental sites.

• In Chile, in the “ Altiplano ” area of the Ist Region of Tarapacà - Province of Parinacota.

• In Ecuador, Province of Tungurahua - Central Ecuador;

• In Peru, Province of Caylloma and in the industrial areas of the same city.

Results

The SUPREME project has provided some scientific and technical results for practical use in ecosystem management for sustainability. Important progress have been achieved in the assessment of the state of relevant natural resources (water, soil and vegetation) and of land use.

The pasture assessment for different experimental areas describes the most representative species and the edible total biomass over the year taking into account the main soil characteristics and the water availability.

The analysis on the introduction of new forage species to improve the vegetation biomass shows a better dry matter production in relation to natural pastures after 3 years of post implantation.

The study on the use and management of natural resources in dry Puna condition points out that water management represents the most effective intervention to improve the vegetation quantity and quality.

According to the natural resources availability, the feeding behaviour and the grazing management practices, the Camelids carrying capacity has been evaluated.

Some of the information achieved is managed by digital data sets and GIS technology. Some of the GIS applications developed include the use of remote sensing (Landsat and NOOAA satellites) to acquire a synoptic evaluation and a multi-temporal monitoring of some environmental parameters (such as vegetation, soil, water availability) and general information on land use.

The Information systems developed allows a spatial reference of multiple thematic layers and the link of cartographic data with tabulated data-bases. This represent an important progress with respect to the majority of previous available information. Some of Information system produced are in use by public and private local operator.

Environmental sustainability indicators (pressure, state, impact, response indicators) aimed to classify the Andean Region in different Environmental Sensitive Areas (ESAs) were selected. According to this classification the critical environmental and land use aspects can be focussed and the most effective and sustainable interventions to improve the Andean ecosystem productivity can be selected.

The main interventions identified by the research are: water management, introduction of new forage species and grazing management practices, such as controlled grazing and grazing feeding integration with stocked forage over the dry season.

The general socio-economic framework for the countries of the Andean Region describes a rather alarming situation which can adversely affect the future of the economy for the communities living in the Altiplano, the development perspectives of Camelid-breeding activities and the development of a market for their products.

From the study carried out emerges the following picture:

• Extreme poverty of the human population: low incomes; low education levels; widespread illiteracy especially among the female population; limited access to basic health services and to communications and energy infrastructures; fragility of the natural ecosystems and exhaustion of soil resources (overgrazing); scarcity of water resources being often an additional problem.

• Inadequate level of technological development in the farming and Camelid breeding activities.

• Economic weakness of farming and stockbreeding activities, forces producers to adopt diversified strategies to improve their incomes (migration).

• The consequent slow drain of the human resources of the Altiplano.

• Scarce or non-existing access to formal credit sources.

• Extremely low levels of investment, as in many cases farming and stockbreeding activities represent a complementary income within a pure survival strategy.

Presently the producers share in the final price of their goods is generally very low, and the terms of exchange of the Altiplano are unfavourable both for meat production and for fibre commercialisation. The causes of such weakness include the fragmentation of production and the absence of producers consortia, and the power of wholesale traders and brokers networks. The migratory process towards the cities or the coasts will likely continue for some time, and unless national governments implement special programs to provide basic services to these populations and to develop local production activities, some areas of the Altiplano will become nearly entirely depopulated.

However in some of the areas under consideration, the development of these activities so as to improve the incomes of producer families seems feasible, possibly with inclusion of tourist service activities in which Camelids may represent an additional attraction. A key factor for this development is the improvement of the quality of the products of the Camelid filière and the interiorisation of a quality oriented culture by the producers. The growth of forms of cooperation and association among producers so as to increase self-reliance in production as well as bargaining power at the product commercialisation stage will play a critical role. The intervention of both governmental and non-governmental organisations alike should be inspired by these two strategic criteria.

The SUPREME project has therefore provided some scientific and technical results that are or can be translated into practical recommendations/tools for the achievement of increased quality in the products on a sustainable basis.

Concerning the feeding behaviour of Alpacas and Llamas in the different plant community produced progress in knowledge of selection ability and metabolic energy requirements. It proved the n-alkanes technique to be a new and effective methodology to study the animal feeding behaviour in its environment.

Concerning animal resources the project produced basic information on the state of the existing population and on the productive attitudes of the various types of animals, suggesting the basic principles of a genetic selection strategy for productive improvement purposes.

The biologic processes governing Camelids fibre production were investigated to a good level of completeness. The definition of the Peruvian Alpaca selection plan represents the fundamental starting point to carry out further research and diffusion activities. Active participation of the Peruvian industry in the program was a key factor of success particularly in the shearing and fleeces management studies.

The different types of Camelid fibre and fleece were well investigated and understood at the microscopical level utilizing also molecular methodology (DNA analysis) in view of fibre certification during industrial processing. In the case of Suri an instrument for objective fibre analyses was set up. For the first time Llama fleece and fibre productions were studied with a systematic approach in Bolivia and Argentina and basic information was provided to manage woolly Llama fibre production at industrial level. The fibres and fleeces colour study was dealt with in a comprehensive way down to the molecular techniques to study genetic transmission of colour in view of the production of uniform coloured fleeces.

The baby fleece study suggested a theory of fleece and fibre maturity at birth and improved the knowledge of the potential for baby fleece production. As the baby fleece is the most requested in the market, these results will permit a future rational management of the baby category and its optimisation with respect to meat production strategy too.

Concerning Camelid meat production, the project identified the optimal slaughter age in Llama and Alpaca and the best carcass management procedure to achieve a good meat quality in Andean conditions.

Meat organoleptic tests were performed directly in South America to provide objective tools for meat quality evaluation. Taking into account of the low nutritional level of human diet presently available in the Altiplano, Camelid meat could be very useful to tackle malnutrition problems in the Andean region, owing to its low fat and high proteins content.

Finally, a DNA primer sets for the differentiation of Camelid from non-Camelid was identified and a Technical Protocol for applying DNA techniques to Camelid fibre identification have been set up. This results could be proposed in the official fibres blend for industrial textiles.

Conclusions

SUPREME is the first project of investigation and technological development carried out simultaneously by all the South American countries interested to the Camelids breeding. The information acquired in several areas where the Camelids are actually bred has a practical application with regard to the sustainable development of this activity.

A good relation and integration between the research groups has been obtained at the scientific and cultural level. The interchange among researchers with different scientific background produced good results in the scientific experimental trials. The main result obtained has been the organisation of all the activities in a filière perspective where all production segments from animal production and pasture management, to the products transformation and commercialisation, have been analysed. This approach has allowed to stress the product quality concept.

The use of native trees for pasture restoration in humid tropical regions

Florencia Montagnini^[36], Luis Ugalde^[37]

Key words: degraded lands, indigenous species, mixtures, reforestation, timber

Introduction

In areas of degraded pastures where potential seed sources are distant, secondary successional processes may be too slow for many farmers to consider as an alternative for pasture recovery. Under these conditions, silvopastoral systems, in which cattle and pastures are combined with trees, shrubs and other crops, may have the greatest probability of adoption (Szott et al., 2000). Research on timber trees for silvopastoral systems should concentrate on selecting high value commercial species that can permit or favor the growth of pastures and tolerate the presence of cattle. This article reports results of studies of growth of mixed and pure tree plantations in Costa Rica. Information on tree form, timber value, and nutrient cycling are considered as factors influencing the suitability of the species for their use in silvopastoral systems.

Materials and methods

Study site

The plantations were established in 1991-192 on abandoned pasture at La Selva Biological Station in the Atlantic humid lowlands of Costa Rica (10^o26'N, 86^o59'W, 50 meters mean altitude, 24^oC mean annual temperature, 4000 mm mean annual rainfall). Twelve native tree species of economic value were planted in three plantations, each with four species: Plantation 1: Jacaranda copaia (Aubl.)D.Don, Vochysia guatemalensis D.Sm., Callophylum brasiliense Cambess and Stryphnodendrom microstachyum Poepp. et Endl.; Plantation 2: Terminalia amazonia (Gmell.)Exell., Dipteryx panamensis (Pittier) Record&Mell, Virola koschnyi Warb and Albizia guachapele (H.B.K.) Little; and Plantation 3: Hyeronima alchorneoides Fr. Allemao, Pithecellobium elegans D.C.Benth., Genipa americana L. and Vochysia ferruginea Mart. The plantations are in randomized blocks, with four replicates and six treatments: four pure plantation plots of each species, a mixed-species plot (with the four species), and a fallow (natural regrowth) plot.

Tree measurements

For each measurement, the total height, DBH, survival, basal area and volume per hectare were compared among the four species of each plantation and the mixed-species plantations using analysis of variance and tests for means (LSD, N = 4, P<0.05).

Results

In Plantation 1, results from measurements taken at 86 months show that the mixed plantations, and the pure plantations of Jacaranda copaia and Vochysia guatemalensis had the largest average diameters at breast height (DBH), with Calophyllum brasiliensis showing average DBH about half that of the other species (Table 1). Both J. copia and V. guatemalensis were the principal contributors to basal area of the mixed plantation plots, and were the two best growing species in mixed plantation conditions. In Plantation 2, at 81 months old, the greatest average DBHs were found in the pure plantations of Virola koschnyi, followed by the pure plantations of Terminalia amazonia, and by the mixed plantations, in that order (Table 1). In Plantation 3, at 70 months old, the greatest average DBHs were found in the pure plantation of Vochysia ferruginea, followed by the pure plantation of Hyeronima alchorneoides, and by the mixed plantation, and the smallest were found in Genipa americana (Table 1).

Discussion

Suitability of the species tested for their use in silvopastoral systems

From the species of Plantation 1, it appears that J. copaia and V. guatemalensis would be good species for agrosilvopastoral systems, due to their good growth in pure and mixed conditions, and the fact that their canopy characteristics allowed for enough illumination to favor the growth of abundant understory. V. guatemalensis is probably the most frequently planted species in the Atlantic lowlands of Costa Rica. In contrast, J. copaia is not being planted by farmers in spite of its good growth, due to its poor timber quality. Of the four species of this experiment, V. guatemalensis had the highest rates of litterfall, and its litter decomposed relatively quickly (Byard et al., 1996) therefore nutrient release from this species could favor growth of associated crop or pastures. Since C. brasiliensis has very good timber quality but slower growth, a good alternative would be to combine it in silvopastoral systems, so that the earlier earnings from the cattle products could help offset the relatively high maintenance costs.

Among the species tested in Plantation 2, V. koschnyi and T. amazonia appear as good potential species for combination in silvopastoral systems, due to their good growth. Growth of understory vegetation was very abundant under T. amazonia (Montagnini et al., 2000), suggesting a good potential for its combination with pastures. V. koschnyi also encourages the growth of abundant understory vegetation (Montagnini et al., 2000). Beneficial effects on some soil nutrients have been reported under V. koschnyi and T. amazonia (Montagnini 2000), again suggesting that these species would aid in soil restoration of degraded lands.

V. ferruginea and H. alchorneoides appeared as the most promising species for silvopastoral combination from the species tested in Plantation 3. In fact, H. alchorneoides is currently being used for combination with cattle in the region. This species encourages the growth of abundant understory (Carnevale and Montagnini, 2000), and results of nutrient cycling studies have shown that growth of test crops was favored from nutrient release from its litter (Horn and Montagnini, 1999). V. ferruginea has abundant leaf litter production that covers the ground and protects against soil erosion (Horn and Montagnini, 2000; Stanley and Montagnini, 1999). This dense litter cover may not favor the growth of pastures under its canopy; however, this effect could be compensated with wider spacing such as is generally used in silvopastoral systems.

The faster growing species of these experiments, such as Vochysia guatemalensis, Virola koschnyi, Hyeronima alchorneoides, can help recover degraded pastures by rapid establishment of tree cover (2-3 years). For the slower growing species such as Calophyllum brasiliense or Dipteryx panamensis, combination with cattle helps offset the higher costs of establishment and maintenance of the tree plantation, and their higher timber value will result in higher revenues in the long term.

In all three plantations, the mixtures performed very well in terms of tree growth and growth of understory vegetation. A mixed-species treatment may combine beneficial effects of the different species’ characteristics, with the additional advantage of product diversification, an important factor among the small farmers of the region.

Table 1. Number of trees per hectare, diameter at breast height (DBH), height, basal area and volume of tree species in pure and mixed plantations at La Selva Biological Station, Costa Rica.

Note:

CALPBR: Calophyllum brasiliense, VOCHGU: Vochysia guatemalensis, JACACO: Jacaranda copaia, VIROKO: Virola koschnyi, DIPRPA: Dipterix panamensis, TERMAM: Terminalia amazonia, GENIAM: Genipa americana, VOCHFE: Vochysia ferruginea, HYERAL: Hyeronima alchorneoides, PITHEL: Pithecellobium elegans, MIXED: mixture of species of a plantation, SR = without thinning; CR = with thinning.

References

Byard R, Lewis K C, Montagnini F (1996) Leaf litter decomposition and mmulch performance from mixed and monospecific plantations of native tree species in Costa Rica. Agriculture, Ecosystems and Environment 58:145-155

Carnevale N J y Montagnini F (2000) Facilitamiento de la regeneración de bosques secundarios por plantaciones de especies nativas. Yvyraretá (Argentina). En prensa

Horn N and Montagnini F (1999) Litterfall, litter decomposition and maize bioassay of mulches from four indigenous tree species in mixed and monospecific plantations. International Tree Crops Journal 10: 37-50

Montagnini F, Campos JJ, Cornelius J, Finegan B, Guariguata M, Marmillod D, Mesén F and Ugalde L (2000) Perspectives for environmentally-friendly management systems in tropical forestry. In: Krishnapullay B, Soepadmo E, Arshad N L, Wong A, Appanah S, Wan Chik S, Manokaran N, Tong H L and Choon K K (eds). Forests and Society: the role of research. IUFRO World Congress, August 6-12, 2000. Sub-plenary Sessions, Volume 1. International Union of Forestry Research Organizations. Kuala Lumpur, Malaysia.

Stanley W and Montagnini F (1999) Biomass and nutrient accumulation in pure and mixed plantations of indigenous tree species grown on poor soils in the humid tropics of Costa Rica. Forest Ecology and Management 113: 91-103

Szott L, Ibrahim M and Beer J (2000) The hamburger connection hangover: cattle pasture land degradation and alternative land use in Central America. Serie Técnica. Informe Técnico No. 313. CATIE, Turrialba, Costa Rica.

Silvopastoral research in Central America: an outlook for the future

Alyson B.K. Dagang^[38], P.K.R. Nair^[39]

Key words: adoption, agroforestry, cattle, extensive pasture

Introduction

Central America’s natural resource base faces enormous pressures from a burgeoning human population, increasing pasture proliferation, and diminishing forest cover. Human population grew 300% from 1961 to 1999, causing substantial expansion of agricultural and pastoral land. During this period, area under pastures increased by 67% resulting in immense deforestation. For example, during the period from 1961 to 1994, forests shrunk by six million ha, a major cause of which was expansion of ranching and livestock production (Wood, 2000). At present, 13 million hectares (26%) of Central America’s total land mass is under permanent pasture (FAOSTAT, 2000). The challenge of balancing human needs with conserving the planet’s natural resources is a complex global problem that eludes viable solutions. In the case of Central America, integration of forests and pastures in silvopastoral systems could be part of a solution.

Silvopastoral systems incorporate dispersed or blocks of tree stands in pastures, providing fruit, wood, shade, fodder for livestock, and habitat for fauna. In addition, grazed and isolated fodder banks produce quality forage for livestock feed supplementation. Research on such systems in the region has enhanced our understanding of some aspects such as nutrient cycling, soil improvement, dry season fodder availability, and biodiversity enrichment, and has suggested the seemingly vast potential of these systems. For example, the region's thirteen million ha of expansive pastures provide ample opportunity for the integration of silvopastoral systems. Such systems could be promoted as a buffer to deforestation and a means of improving pasture productivity (Huxley, 1999). In spite of these suggested advantages and potential, silvopastoral systems and technologies are not being adopted on a wide scale in Central America. In this paper, we will review silvopastoral research of the 1990s in Central America and elsewhere, and examine the reasons for the low level of adoption of the technologies in the region.

Research findings

Nutrient cycling in silvopastoral systems

Trees can enrich soil conditions in agroforestry systems through various biological processes and mechanisms including increase in soil organic matter content from fine root sloughing and litterfall, increased soil N through N₂ fixation, (Nair et al., 1999; Nygren et al., 2000), changes in soil chemical, physical, and biological properties by meso and micro fauna around roots, and enhancement of the total nutrient pool by faunal droppings (Tornquist et al., 1999; Wedderburn and Carter, 1999; Belsky et al., 1993). In a long-term study in semiarid NE Brazil, two native species in pastures of varied conditions were shown to significantly increase available P and total C, and increase exchangeable K by 50% (Wick et al., 2000). Leguminous species such as Leucaena leucocephala can obtain 75% of their N from biological fixation. Gliricidia sepium, a N₂ fixing tree, has been observed to produce 112 kg N /ha during an eight month period grown in pasture in Sri Lanka (Jayasundara et al., 1997).

In some cases, it has been shown that N₂ fixing trees planted in silvopastoral systems can transfer N to companion grasses. In mixed pastures of Leucaena leucocephala and Setaria sphacelata, transfer of N from the tree component to grass has been reported. Setaria derived 21% of its N from the companion trees and in comparison with a grass monoculture, Setaria had a 16% higher N yield (Jayasundara et al., 1997). Rao and Giller (1993) observed transfer of N from Leucaena diversifolia to Cenchrus ciliaris roots and leaves. In this study, pollarding of trees had a significant, positive effect on N transfer. However, N production and transfer can depend on a number of factors such as the system’s management regime, intimacy of the component parts, and the methods by which the processes are measured (Liyanage et al., 1994). In addition, transfer of other nutrients can be dependent on tree age, microbial population, soil conditions, and plant nutrient deficiencies (George et al., 1996; Danso et al., 1992).

Hydraulic lift

In addition to accessing nutrients from deeper layers of soil, trees hydraulically lift water from deeper layers and distribute it on the soil surface in response to dry environmental conditions (Caldwell et al., 1998; Horton and Hart, 1998; Nepstad et al., 1994). Emerman and Dawson (1996) and Burgess et. al (1998) attribute maintenance of fine root viability in dry soil to such hydraulic lift and indicate that an active root system allows trees and other plants to utilize water available in deeper soil layers, enabling plants to maximize water acquisition during drought conditions and increase plants’ ability to acquire resources in times of scarcity. Possibility of the existence of hydraulic lift could have important consequences for silvopastoral systems.

Tree fodder legumes

Extensive research has been conducted on nutritive values, benefits, and adverse effects of tree fodder legumes such as Leucaena spp., Gliricidia sepium, Sesbania spp., Calliandra calothyrsus, and Erythrina spp. The main objective of such research has been to assess the ability of tree fodder legumes to meet production needs brought about by low-protein animal diets and dry season fodder scarcity (Ibrahim et al., 2000; Huxley, 1999; Larsen et al. 1998). These investigations have suggested viable options for livestock supplementation and increased animal production through the use of tree fodder legumes (Gutteridge, 1994; Shelton et al., 1991). For example, Gliricidia sepium produces high quality forage with 20 to 30% crude protein concentration, 15% crude fiber content, 60 to 65% digestibility, and abundant dry matter production of 3 to7 t/ha/yr (Simons and Stewart, 1994; Escalante, 1998; Adejumo, 1992). Leaves of Erythrina poeppigiana have been observed to have 42% crude protein concentration and 49% protein solubility. Although experiments have shown a 61% cell wall content, lignin in E. poeppigiana is similar to that of other tree legumes (Kass, 1994). Nutritive values of Sesbania spp. are reported to be superior to those of other legumes such as Gliricidia, and dry matter digestibility of its foliage ranges from 66 to 75%. However, live weight gains from feeding trials of Sesbania are lower than those of other tree legumes. According to Gutteridge (1994), nominal weight gains from Sesbania forage despite its high quality indicate the existence of anti-nutritive factors that limit full exploitation of the forage. Calliandra calothyrsus is a prolific species, producing 7 to 10 t/ha/yr of dry matter (Palmer et al., 1994). However, observed high tannin levels may hinder its use as fodder. In a study in the Kenyan highlands that compared forage production of Calliandra and Leucaena alley-cropped with napier grass (Pennisetum sp.), Nyaata et al. (1998) found that Calliandra reduced napier grass biomass yields by almost 50% in comparison to Leucaena, indicating Calliandra’s potentially competitive effect on companion species.

Leucaena is known to produce 7 to 20 t/ha of biomass depending on cutting regime and climate (Cobbina, 1998). As the most commonly used and researched tropical fodder legume, Leucaena foliage has a digestibility of 42 to 70% and crude protein concentration of 15 to 40% (Dalzell et al., 1998). In lowland Kenya, Abdulrazak et al. (1996) observed linear live weight gains in steers given incremental supplements of Gliricidia and Leucaena forage with napier grass. In this study, when legume was fed as 27% of total dry matter, a 57% increase in live weight gain resulted. In Australia, New Guinea, Philippines and Florida, USA, studies of different species of Leucaena have indicated differences in forage quality and acceptability by livestock. L. leucocephala and L. collinsii produce higher weight gains, higher digestibility, and palatability in steers, coupled with lower tannin levels when compared to L. trichandra, L. pallida, and L. diversifolia (Jones et al., 1998; Austin et al., 1995).

Unique to forage tree legumes is the ability to maintain green foliage during drought. Unlike most grasses, tree roots access water and nutrients in deeper soil layers and thereby maintain green foliage during dry periods. However, a tree’s ability to maintain its leaves during drought can depend on its management. Presence of foliage during water stress has been linked to pruning prior to the dry period. In addition, foliage production has been shown to correlate significantly with age at first tree pruning (Adejumo, 1992; Ella et al., 1991).

Biodiversity enhancement

Two types of silvopastoral systems, live fences and dispersed trees, can be commonly found in pastures throughout Central America. Gliricidia sepium and Erythrina spp. are among the most commonly utilized species in live fences (Kass, 1994). Holmann et al. (1992) found that a 1 km live fence of Erythrina beteroana contributed 453 kg N, 31.2 kg P, and 166.2 kg K to soil per year. Various isolated tree species are commonly found in pastures and are maintained for a multitude of uses including shade, fuelwood, timber, and fruit. Harvey and Haber (1999) found ninety species on a single farm in Costa Rica. A new body of research is emerging on dispersed trees, providing valuable results concerning trees’ effects on biodiversity enrichment and their augmentation of forest fragment habitats (Harvey et al., 1998).

Farmer adoption of silvopastoral technologies

Despite the abundance of research results on the positive effects of trees on pasture and animal production, farmer adoption of the technologies is limited. It is therefore imperative that a new research approach is taken to address the risks of technology adoption and assess the potential for integration of silvopastoral technologies into producers’ livelihood strategies.

If farmer adoption rests on the premise that new technology must either increase yields, decrease costs, decrease risk (Bunch and Lopez, 1995), or offer multiple products in a relatively short time, then silvopastoral research must gear its pursuits toward technologies that do not delay positive results, stimulate innovation among producers, are low-risk, and render a tangible, favorable impact on farming systems (Van Veldhuizen et al., 1997; Hildebrand and Russell, 1996). For example, research has shown repeatedly that integration of a grazed fodder bank can bring about positive increases in animal production. However, lengthy establishment period and the sacrifice of pasture area delay positive results and therefore hinder adoption (Argel et al., 1998). Alternatives to or enhancement of this technology through research on establishment, species that offer multiple products or other options, may lead to increased adoption.

Outlook for silvopastoral research in Central America

A change in outlook and approach toward low tropical pasture productivity should be considered. Such an approach must begin by examining sub-optimal pasture productivity not as the problem focus, but as the consequence of inefficient farm resource management. By examining resource use on-farm and discerning consequent low pasture productivity, researchers will be better able to hone their work toward adoptable and adaptive, farmer-friendly technologies. It is imperative that researchers conceive that farmers manage resources to optimize their perceived gains and objectives while system dynamics and constraints dictate producers’ decision making. Understanding farm goals, farmer motivation, and limitations is necessary for identifying farmer-appropriate- research targets and endeavors. By recognizing what drives producers’ management practices, choices, and constraints, research will be better able to address farmers’ needs and produce viable research results.

Without adoption, applied agroforestry research is for naught. The silvopastoral research agenda must give precedence to adoption: how it is generated, what limits it, and why Central American farmers, who suffer cattle losses during the dry season, currently choose not to integrate silvopastoral systems into their cattle operations. If research can embrace obstacles such as these, work in partnership with farmers throughout the research process, recognize the importance of adoption and guide efforts that will address these problems, future research will be better able to tailor and execute its study of appropriate, adaptive technologies.

References

Abdulrazak SA, Muinga RW, Thorpe W, and Orskov ER (1996) The effects of supplementation with Gliricidia sepium or Leucaena leucocephala forage on intake, digestion and live-weight gains of Bos taurus x Bos indicus steers offered napier grass. Animal Science 63: 381-388

Adejumo JO (1992) Effect of plant age and harvest date in the dry season on yield and quality of Gliricidia sepium in southern Nigeria. Tropical Grasslands 26: 21-24

Argel PJ, Lascano CE and Ramirez L (1998) Leucaena in Latin America Farming Systems: Challenges ofr Development. In: Shelton HM, Gutteridge RC, Mullen BF, and Bray RA (eds) Leucaena-Adaptation, Quality, and Farming Systems, Proceedings No. 86. Australia, ACIAR pp 319-323

Austin MT, Williams MJ, Hammond AC, and Weiguo S (1995) Establishment, forage, production, and nutritive value of Leucaena in Central Florida. Agronomy Journal 87: 915-920

Belsky AJ, Mwonga SM, Amundson RG, Duxbury JM, and Ali AR (1993) Comparative effects of isolated trees on their undercanopy environments in high and low rainfall savannas. Journal of Applied Ecology 30: 143-155

Bunch R and Lopez G (1995) Soil Recuperation in Central America: Sustaining Innovation after Invention. Gatekeeper Series no. SA55. London, England, Sustainable Agriculture Programme, International Institute of Environment and Development. 18 p

Burgess SSO, Adams MA, Turner, NC, and Ong CK (1998) The redistribution of soil water by tree root systems. Oecologia 115: 3 306-311

Caldwell ME, Dawson TE and Richards JH (1998) Hydraulic lift: consequences of water efflux from the roots of plants. Oecologia 113: 151-161

Cobbina J (1998) Forage productivity and quality of Leucaena as influenced by tree density and cutting interval in the humid tropics. In: Shelton HM, Gutteridge RC, Mullen BF, and Bray RA (eds) Leucaena-Adaptation, Quality, and Farming Systems, Proceedings No. 86. Australia, ACIAR pp 253-256

Dalzell SA, Stewart JL, Tolera A, McNeill DM (1998) Chemical composition of Leucaena and implication for forage quality. In: Shelton HM, Gutteridge RC, Mullen BF, and Bray RA (eds) Leucaena-Adaptation, Quality, and Farming Systems, Proceedings No. 86. Australia, ACIAR pp 227-246

Danso SKA, Bowen GD, and Sanginga, N (1992) Biological nitrogen fixation in trees in agro-ecosystems. Plant and Soil 141: 177-196

Ella A, Blair GJ, and Stur WW (1991) Effect of age of forage tree legumes at the first cutting on subsequent production. Tropical Grasslands 25: 275-280

Emerman SH and Dawson TE (1996) Hydraulic lift and its influence on the water content of the rhizosphere: an example from sugar maple, Acer saccharum. Oecologia 108: 273-278

Escalante E (1998) The role of fodder trees in agroforestry systems in Venezuela. In: Daniel J and Roshetko J (eds) Forest, Farm, and Community Tree Research Reports -Special Issue. Farm Forest and Community Tree Network of Winrock International, Arkansas pp 187-192

FAOSTAT (2000) FAO Statistical Databases http://apps.fao.org/

George SJ, Kumar BM, Wahid PA, and Kamalam NV (1996) Root competition for phosphorous between the tree and herbaceous components of silvopastoral systems in Kerala, India. Plant and Soil 179: 189-196

Gutteridge RC (1994) The perennial Sesbania species. In: Gutteridge RC and Shelton HM (eds) Forage Tree Legumes in Tropical Agriculture. UK, CAB International pp 49-64

Harvey CA and Haber WA (1999) Remnant trees and conservation of biodiversity in Costa Rican pastures. Agroforestry Systems 44: 37-68

Harvey CA, Haber WA, Mejias F and Solano R (1998) Remnant trees in Costa Rican pastures, tools for conservation? Agroforestry Today July-Sept: 7-9

Hildebrand PE and Russell JT (1996) Adaptability Analysis: A Method for the Design, Analysis and Interpretation of On-Farm Research-Extension. Ames, Iowa, Iowa State University Press. 189 p

Holmann F, Romero F, Montenegro J, Chana C, Oviedo E, and Banos A (1992) Rentabilidad de sistemas silvopastoriles con pequenos productores de leche en Costa Rica: primera aproximacion. Turrialba: 42:1 79-89

Horton JL and Hart SC (1998) Hydraulic lift: a potentially important ecosystem process. Trends in Ecology and Evolution 13:6, 232

Huxley, PA (1999) Tropical Agroforestry. Malden, MA, USA, Blackwell Science. 389 p

Ibrahim MA, Holmann F, Hernandez M, and Camero A (2000) Contribution of Erythrina to protein banks and rejected bananas for improving cattle production in the humid tropics. Agroforestry Systems 49: 245-254

Jayasundara HPS, Dennett MD and Sangakkara UR (1997) Biological nitrogen fixation in Gliricidia sepium and Leucaena leucocephala and transfer of fixed nitrogen to an associated grass. Tropical Grasslands 31: 529-537

Jones RJ, Galgal KK, Castillo AC, Palmer B, Deocareza A, and Bolam M (1998) Animal production from five species of Leucaena. In: Shelton HM, Gutteridge RC, Mullen BF and Bray RA (eds) Leucaena-Adaptation, Quality, and Farming Systems, Proceedings No. 86. Australia, ACIAR pp 247-252

Kass DL (1994) Erythrina species - pantropical multipurpose tree legumes In: Gutteridge RC and Shelton HM (eds) Forage Tree Legumes in Tropical Agriculture. UK, CAB International 84-96

Larsen PH, Middleton CH, Bolam MJ and Chamberlin J (1998) Leucaena in large-scale grazing systems: challenges for development. In: Shelton HM, Gutteridge RC, Mullen BF and Bray RA (eds) Leucaena-Adaptation, Quality, and Farming Systems, Proceedings No. 86. Australia, ACIAR pp 324-330

Liyanage M de S, Danso SKA, and HPS Jayasundara (1994) Biological nitrogen fixation in four Gliricidia sepium genotypes. Plant and Soil 161: 267-274

Lott JE, Khan AA, Ong CK, and Black CR (1995) Sap flow measurements of lateral tree roots in agroforestry systems. Tree Physiology 16: 995-1001

Nair PKR, Buresh RJ, Mugendi DN and Latt C R (1999) Nutrient cycling in tropical agroforestry systems: Myths and science. In: Buck LE, Lassoie JP and Fernandes ECM (eds) Agroforestry in Sustainable Agricultural Systems. Boca Raton, FL., CRC Press pp1-31

Nepstad DC, de Carvalho CR, Davidson EA, Jipp PH, Lefebvre PA, Negreiros GH, da Silva ED, Stone TA, Trumbore SE and Vieira S (1994) The role of deep roots in the hydrological and carbon cycles of Amazonian forests and pastures. Nature 372: 666-669

Nyaata OZ, O’Neill MK and Roothaert RL (1998) Comparison of Leucaena leucocephala with Caliandra calothyrsus in napier (Pennisetum purpureum) fodder banks. In: Shelton HM, Gutteridge RC, Mullen BF, and Bray RA (eds) Leucaena-Adaptation, Quality, and Farming Systems, Proceedings No. 86. Australia, ACIAR pp 257-260

Nygren P, Lorenzo A, and Cruz P (2000) Decomposition of woody legume nodules in two tree-grass associations under contrasting environmental conditions. Agroforestry Systems 48: 229-244

Palmer B, Macqueen DJ, and Gutteridge RC (1994) Calliandra calothyrsus - a multipurpose tree legume for humid locations. In: Gutteridge, RC and Shelton HM (eds) Forage Tree Legumes in Tropical Agriculture. UK, CAB International pp 65-74

Rao AV and Giller KE (1993) Nitrogen fixation and its transfer from Leucaena to grass using ¹⁵N. Forest Ecology and Management 61: 221-227

Shelton HM, Lowry JB, Gutteridge RC, Bray RA and Wildin JH (1991) Sustaining productive pastures in the tropics 7. Tree and shrub legumes in improved pastures. Tropical Grasslands 25: 119-128

Simons AJ and Stewart JL (1994) Gliricidia sepium - a multipurpose forage tree legume. In: Gutteridge RC and Shelton HM (eds) Forage Tree Legumes in Tropical Agriculture. UK, CAB International pp 30-48

Tornquist CG, Hons FM, Feagley SE and Haggar J (1999) Agroforestry system effects on soil characteristics of the Sarapiqui region of Costa Rica. Agriculture, Ecosystems, and Environment 73: 19-28

Van Velduizen L, Waters-Bayer A and De Zeeuw H (1997) Developing Technology with Farmers: A Trainer’s Guide for Participatory Learning. London, Zed Books. 283 p

Wedderburn ME and Carter J (1999) Litter decomposition by four functional tree types for use in silvopastoral systems. Soil Biology and Biochemistry 31: 455-461

Wick B, Tiessen H and Menezes RSC (2000) Land quality changes following the conversion of the natural vegetation into silvo-pastoral systems in semi-arid NE Brazil. Plant and Soil 222: 59-70

Wood S, Sebastian K and Scherr SJ (2000) Pilot Analysis of Global Ecosystems: Agroecosystems. Washington DC, International Food Policy Research Institute and World Resources Institute. 93 p

Silvopastoral systems in the leeward side of Guadeloupe: conditions and objectives of study.

G. Alexandre^[40], A. Larade^[41], M. Anselme^[42], H. Archimède^[43]

Key words: livestock-environment relationships, sustainability, traditional production systems

Introduction

The National Park of Guadeloupe is in charge of the land management of the leeward side of the island (Côte Sous le Vent, CSV). Recently a program has been set up in order to promote a sustainable development plan (Le Parc 1999). A range of altitude from 0 m to more than 800 m (with many mountainous parts) characterises this CSV. Natural, agricultural and urban spaces are gradually distributed according to altitude, climatic constraints and biophysical conditions, from the dry lowlands (coastal region) to the humid hillsides. Unfavourable economic conditions, inadequate land management policies and natural disasters have been responsible for the low level of development of CSV. On the contrary, valuable human and natural characteristics - among them, traditional integrated crop-tree-livestock systems, very attractive and diverse landscapes and high biodiversity of natural and agricultural spaces - could support this new program. In that sense, an inter-disciplinary co-operation between forestry and land management agents and livestock researchers is now being carried out in the field of agrosilvopastoral systems. Objectives are to enhance their environmental services (landscapes modelling for tourism development, biodiversity and soils conservation, rehabilitation of degraded forest or pasturelands), to increase livestock productivity and finally to identify decision-making tools.

Area characteristics

Guadeloupe (French West Indies) is a humid tropical island of the Caribbean, (16,1° N, 61,6° W) small sized (1700 square km) and overpopulated (400 000 inhabitants). The area of study is located in the leeward side of the island (Côte Sous le Vent, CSV). The CSV population accounts for about 25 000 inhabitants disseminated in four villages spreading over 19 300 ha (table 1).

Land physical conditions

A range of altitude from 0 m to more than 800 m (with many mountainous parts) characterises this CSV. Natural, agricultural and urban spaces are gradually distributed according to relief constraints. Soils are formed from volcanic rocks, the main ones consist of oxysols and vertisols and are fine or coarse textured. In the highlands, the soil depth is low.

Climate is diversified and presents wet and dry seasons (Lassere 1982). In the southern area, rainfall ranges from 1200 (sea level) to 12000 mm (higher peak). Vegetation zones are related to rainfall distribution. The climatic climax vegetation of CSV is mainly tropical rainforest and tropical semi-deciduous forest.

Land use

Main values of grazing land area and livestock heads are tabulated in table 1. Only 22 % of the total agricultural land of this region is devoted to the production of forage (i.e. 518 ha). Additionally rangelands spreading over 678 ha, are potentially grazable areas. They include natural grasslands and savannas in the dry lowlands of the coastal region and include shrublands and mountain meadows in the humid hillsides. As in many parts of the island, the pasturelands and the rangelands are dominated by indigenous vegetation (Lassere 1982, Le Parc 1999)

The CSV large and small ruminants account for 1042 and 3336 heads representing 1.6 % and 10.5 % of the total population, respectively. Same figures were related by Salas 1989 for cattle and Alexandre et al., 1991 for goats: ten years ago the CSV cattle and goats population represented 3 % and 18 % of the total guadeloupean population, respectively.

Table 1. Main land use and livestock characteristics of the four villages of the leeward side of Guadeloupe (Côte sous le Vent, CSV)

Systems of production in Côte sous le Vent

Traditional CSV agroforestry system

Fields are disseminated according to land availability and to altitude distribution: either homestead-garden or even clearing in the forest. The majority of CSV people depends on the forest for cooking and firewood. But in fact, the depletion of the rainforest for these purposes, although a concern for many, has been insignificant compared to other countries. In CSV, land traditional use is a system in which woody perennials are exploited either for wood production or for charcoal. Very frequently in the same area, the land bears evidence of former forest that have been converted to other vegetation. There appear fruit trees, shrubs and herbaceous forbs and cultivated crops. The garden is under intensive, permanent production and contains a mix of perennial and annual crops grown in a complex agroecosystem. Moreover, agricultural crops are grown and fruits are harvested in order to support family consumption and sometimes to be sold at the very local level. The rangeland is grazed. Some parts of this region are forestland (representing 25 % to 50 % of total area) that produces sufficient understory vegetation that can be grazed. Traditional tethering animal systems are undertaken in mountainous parts of the CSV especially during the dry season because they can support grazable forestland. On the other hand, rangeland, where indigenous vegetation is either grasses or grass-like plants or forbs and plants, is managed as a natural ecosystem. CSV populations depend on agriculture to survive and this system is the CSV traditional agroforestry. Moreover, this system supports another sector linked to the well being of people: pharmacopoeia. The majority of CSV people have always opted for herbal treatment over Western medicine. Some hardwood species, like Mahogany well known in Guadeloupe, are grown in order to support the wood sub-sector in this region very famous for its traditional finished furniture. But exploitation of Guadeloupean timber, used mainly in the construction and the furniture business, for commercial purposes is scarce.

Traditional CSV animal production systems

Nine percent of the total number of livestock producers (LP) owning large and/or small herbivores have been investigated the 6 last months. 8 % of the farmers breed chicken and duck. On the other hand, hives are numerous but this sector has not been studied because honey production is for family consumption or because bee owners are located elsewhere in the island. Horses and asses are reared among 6 % of livestock producers. Results are tabulated for cattle, goat and pig numbers (table 2). Classes have been discriminated according to the number of total heads bred by the LP. In major cases, whatever the species is, the herd is small-sized. Animal production is one of the numerous activities undertaken by the farmers, including non-agricultural ones. 40 % of them are commercially oriented for both crops and animal products. The local CSV market is the main one (except for the banana and for the citrus products). The LP rarely interfere with the vital cycle of their animals, reproduction is carried out all year long owing to the great reproductive abilities of the local breeds reared in CSV. Questions about animal disease constraints do not arise as limiting factor for animal production in this region. Grazing natural dry savannas or humid mountainous meadow, browsing shrubs or tree foliages available in the natural ecosystem are the main feeding practices. The traditional tethered animal system, based upon a strong traditional know-how of local LP (Boval 1995) is widespread even on steep slopes. It allows to graze any available feed resource whatever the area dimensions and altitude are. Livestock are a feature of the homestead and adjacent areas and they feed on fallow and residues of the harvested fields.

Table 2. Herd characteristics of CSV livestock producers (LP): different classes of herd size (number of heads) and percentage of LP owning cattle, goats or pigs.

Diagnosis and perspectives

It’s well-documented (TED 1999) that in the cases of Costa Rica or Ghana, the impact of deforestation is widespread, affecting the livelihood of local people, disrupting important environmental functions and severely disturbing the biological integrity of the original forest ecosystem. In the Caribbean region, there is a serious concern about climatic change, soil erosion and large-scale desertification. In Haiti for example, deforestation has claimed an enormous toll through the ages in environmental damage, economic deterioration and human misery. That is the reasons why, in the case of Guadeloupe CSV, these damages must be avoided. First of all, it is highly recommended not to improve animal production by the way of intensive grazing system or by expanding ranching systems.

Objectives

The land management agents of the National Park of Guadeloupe together with the INRA animal researchers are willing to promote decision-making tools, to determine social norms and codes of conduct as well as to define technical options aiming at different objectives:

- to enhance potential positive contribution of livestock production systems (biodiversity and soils conservation, and rehabilitation of degraded forest or pasturelands) or to reduce their negative impacts where changes are required (regions with very high slopes, fragile soils, natural forestland);

- to increase number of small farmers and/or to improve their economic results with better tree-crop-livestock systems of production while promoting animal roles in stronger crop-livestock relationships (such as manure for agricultural crops or agricultural by-products in pigs feeding);

- to set up systems of production based upon breeding of local genotypes, matching to available feed resources (forbs, tree foliages and by-products) as well as to avoid destructive process of deforestation (principally motivated by unfavourable economic conditions and short-sighted government policies);

- to extend the animal product market at the local level for CSV people and for tourists (thus facilitating collective action and benefit sharing among users groups) while diversifying the animal products (such as meat goat for traditional curry goat or animal power for horse and donkey hill-ridding);

- to put forward animal benefits for eco-tourism development: landscapes modelling, picturesque scenery with local animal (tethered Creole cattle and goat or pig tied under mango tree) attractive for tourists;

- and to give farmers, and even animal owners, due recognition for the many significant environmental benefits afforded by livestock production under suitable conditions.

Research planning

There is a dearth of factual information about type and numbers of animal concerned and practices and objectives of farmers. Three kinds of studies would be carried out in two different areas of this region representing diverse conditions (natural pastures, brushes and bushes in the dry coastal lowlands as well as agrosilvopastoral systems disseminated in the humid forest hillsides). First, silvopastoral systems of production would be described (conditions, structure, pasturelands, tree-fodder resources, animals, traditional technologies, management practices). They would be investigated in order to determine their main assets and constraints, and environmental and socio-economic issues. In a second study, biophysical conditions, botanical composition, biomass levels and feeding values would be determined in a one-year experiment taking into account geographical and seasonal variations. Forage allowance would be assessed in terms of dry matter per unit area according to various factors of variation: regions (hillsides vs seaside), types of forage (herbage vs browse), seasons, characteristics of landscape position, soils and hydrology in order to determine different levels of animal carrying capacity. This latter term would allow setting up rules of suitable grazing land management. In addition, on-farms experiments would be carried out in order to improve pasture and tree-fodder management in livestock oriented systems.

These further studies claim for livestock-environment complementarity as reported by Mearns (1997) and aim at sustainable development (Le Parc 1999).

References

Alexandre G, Borel H, Matheron G, and Remy C (1991). Elevages caprins en Guadeloupe. Revue d’ Elevage et de Medecine Veterinaire des Pays tropicaux (special issue): 27-40.

Boval M (1995) La conduite à l’attache de bovins créoles. Etude des quantités ingérées. Thèse de doctorat de l’Université de Paris VI. 96 p

Lasserre G (1982) Atlas des départements français d’Outre Mer: La Guadeloupe. Paris, CNRS. 99 p

Mearns R (1997) Livestock and environment : potential for complementarity. World Animal Review 88 : 2-14

Parc National de la Guadeloupe (1999) Diagnostic territorial et 1ères orientations pour un développement durable de la Côte sous le Vent . Documents de travail. 88 p.

Salas M (1989) Systèmes d'élevage bovin allaitant en Guadeloupe. Diagnostic et voies de développement. Thèse de doctorat de l'université. Université Paris XII. 347 p.

TED Trade and Environment database (1999) Case Studies of beef exports in Costa Rica and in Ghana.

Effect of native tree legumes on soil restoration under agroforestry systems in the South of Mexico

E. Hernández-Cruz^[44], S. Palacios-Mayorga^[45]_, J.E. Gama-Castro^[46], and V. Cervantes^[47]

Key words: CO₂ evolution, native tree legumes, soil aggregation, soil restoration

Introduction

According to the FAO (1996), the most severely damaged ecosystems in the world are located in tropical indigenous communities and are due to the change caused by indiscriminate soil-use, a change that has accelerated during the last three decades. In Mexico, which is part of this environmental problem, more than 85% of our territory shows various soil degradation problems, particularly biological soil degradation and erosion. These conditions are found in both the lowland and mountainous tropical areas in the south of México (Gama et al., 1996). Looking for ecological and socioeconomic alternatives that could be adapted to these areas, we believe that agroforestry systems offer one of the best options. Many of the tree and shrub species that have been incorporated into these systems are legumes. The importance of these species in soil restoration and soil fertility maintenance is well known (Nair, 1984; Young, 1997; Tornquist et al., 1999). The objective of this work was to evaluate the effect of an agroforestry system with three native woody legumes established in disturbed deciduous tropical forest soils (Entisols) that have been opened to annual agriculture and pasturage.

Materials and methods

The study area is situated in San Nicolas Zoyatlán, Guerrero state, Mexico (17° 27’ N and 28° 38’ W). The climate may be classified as warm to semi-hot. The mean annual temperature is 27.5°C and average annual precipitation is 731mm. In these areas the elevation ranges from 1300 to 1700m, and slopes range from 1 to 75%. The original vegetation is deciduous tropical forest. The main impact of deforestation occurred approximately 100 years ago, and current vegetation consists of secondary growth and grasses with remnants of primary growth (Cervantes, et al., 2000).

The field experiment consisted of three mono-specific planted bands separated by open alleys plus a fourth unplanted control plot. Three native species of tree legumes were used: Leucaena esculenta, Acacia macilenta and Lysiloma divaricata. Potential field survival and plant growth plus the farmer’s preference were the principle considerations in the selection of the legume species. In each alley a soil sampling was made taking four sub-samples, from 0 to 30 cm deep, for each legume species.

Physical and chemical soil analyses were made on air-dried soil samples passed through a 2 mm sieve and determined as described by the USDA (1996). Thin sections were made and examined with a petrographic Zeiss microscope in plane and polarized light. Micro-morphological properties of soil samples were determined as described by Bullock et al. (1985). Soil aggregate size and stability were determined according to Savvinov (Kaurichev,1980). The Chemical plant analyses were made according to USDA (1996).

The efflux of CO₂ from soil (“soil respiration”) was measured by means of a random experiment in which soils were treated with the dried and ground leaves of one of each of the specific legume and incubated in glass flasks for periods of 8, 16 and 32 days (Pramer, 1974; Anderson, 1996).

Results and discussion

Soil analysis.

The soils examined in this experiment were shallow and poorly developed, with loose grains and coarse textures. Their pH values varied from slightly acid to alkaline; base cation content fluctuated from poor to medium, and OM contents were moderate. However, all cation exchange capacity values corresponded to a high potential rate of soil fertility. These values come from the presence of variable charges due to volcanic glass weathering. By their features, these soils can be classified as Regosols and Leptosols.

Effect on soil structure and aggregation.

The micro-morphological photographs of the soils gave us a clear picture of the effect of the legumes on the soil structure (Fig 1). The control plot soil (Fig. 1-A) shows a lack of soil aggregation; loose grains of pyroclastic and lithic materials and felsitic minerals are predominant. In contrast, a clear effect on soil aggregation was observed in figure 1-B (L. esculenta) where aggregates varied from weak to moderate. In 1-C (A. macilenta) and 1-D (L. divaricata) aggregates were moderately developed. Increased aggregation corresponded to a major OM content (Table 1). Similar results have been described by several authors (Mapa and Gunasena, 1995). The analyses of aggregate stability can be arranged in the following gradient: 1-D> 1-C> 1-B> 1-A. The microphotographs show round and sub-round aggregates with a high porosity density. This type of aggregation decreases soil erosion and produces an increment in water and air permeability, consequently improving root development (Mapa and Gunasena, 1995).

Plant analysis.

The chemical composition of foliage revealed a very low C:N ratio. However no significant differences were found among plant species (Table 2). The TN detected in the experimental plants were high compared with other legume species (Oorts et al., 2000). These results correspond to a higher potential effect on soil amelioration and better soil nutrient balance (Lal, 1989). Low C:N ratios are also characteristic of high levels of organic matter mineralization (Tornquist, et al., 1999).

Table 1. Some physical and chemical properties of the arable soils (0-30 cm)

^a Average ± Standard deviation of four sub-samples.

CO₂ evolution.

Significant differences (p£0.01) were found among legumes and incubation periods. These results probably were due to the different C:N ratio of each legume. In contrast, no significant differences were noted among incubation periods in the control soil. The highest CO₂ efflux among legumes was that of L. esculenta incubated for 32 days. Also this legume produced one of the best effects on soil aggregation (Fig. 1-B).

Table 2. Carbon and nitrogen concentration of selected legumes foliage.

Conclusions

The differences in aggregation levels observed between soils from alleys with and without legumes can be attribute to the effect of the organic matter added to the soil by these plants. However, the aggregates’ quality was probably due to the specific effect of the individual legume species used in the agroforestry system.

References

Anderson JM and Ingram, JSI (1996) Tropical soil Biology and Fertility: A Handbook of Methods. 2 ed Cab International UK

Bullock P N, Fédoroff N, Jongerius A, Stoops G, Tursina T (1985) Handbook for Soil Thin Section Description. Wayne Research Pub., Albrigton, England

Cervantes, V., M. López, N. Salas y G. Hernandez (2000) Técnicas para propagar especies nativas de la selva baja caducifolia y criterios para establecer de reforestación. In prensa. Semarnap- UNAM. México. 200 p.

FAO (996) El desarrollo rural sostenible: Progresos y problemas, Cuarto Informe sobre los progresos realizados en la aplicación del programa de acción de la CMRADR, FAO, Roma, Italia

Gama-Castro J E, S Palacios-Mayorga, M and Villegas-Soto (1996). Hidroerosión de Suelos de Tepetzingo, Morelos, México. Revista de Edafología Mexicana, Instituto de Geología, UNAM 1: 1-15

Kaúrichev, I.S., Panov NP Stratonóvich MV and Grechin IP (1980) Prácticas de Edafología. Ed. Mir, Moscú. pp: 94-95

Lal R (1989) Agroforestry systems and soil surface management of tropical alfisol: III: Changes in the soil properties. Agroforestry systems 8:113-132

Mapa R.B. and H.P.M. Gunasena. (1995) Effect of alley cropping on soil aggregate stability of tropical. Agroforestry Systems 32: 237-245.

Nair, P.K.R., Fernandes, E.C.M. and Wambugu, P.N. (1984). Multiporpose leguminous trees and shrubs for agroforestry. Agroforestry Systems. 2:145-163.

Oorts K, B. Vanlauwe, O. Cofie, N. Sanginga and R. Merckx (2000) Charge Characteristics of soil organic matter fractions in a Ferric Lixisol under some multipurpose trees. Agroforestry systems 48: 169-188

Pramer D and EL Schmidt (1974) Experimental Soil Microbiology. USA, Burgess Publishing Company, 107 p

Soil Conservation Service (1996) Procedures for collecting soil samples and methods for analysis for soil survey. Soil Survey Investigations Report No. 8. US Departament of Agriculture, Soil Conservation Service, Washington, D.C.

Tornquist C. G., Hons, F.M., Feagley S.E. and J. Haggar (1999) Agroforestry system effects on soil characteristics of the Sarapiqui region of Costa Rica. Agriculture, Ecosystems and Enviroment 73: 19-28.

Young A (1997) Agroforestry for soil conservation. 2 ed. ICRAF Nairobi, Kenya

Reclamation of sodic soils “through investment in people” - A success story

Ajay Sehgal^[48]

Key words: community participation, pastureland, Shram-dan, soil reclamation, village forest committee

Introduction

Simultaneous land degradation and explosion of population are the basic agrarian problems in North India .Consequently pressure on farm and forest land increases . As such out of a total of 329 Mha about 174 Mha of land is degraded in India. Unrestricted tree felling, overgrazing, deliberate fires and clearing of land for agriculture are the undisputed apparent reasons. Further erratic distribution of rainfall, lack of irrigation facilities, urge for over productivity through energy subsidies and small land holdings have further compounded the problem. Soil, the basic life support system, if once degraded, results in slow and difficult recovery .The deterioration in the soil fertility, productivity and land qualities have become a matter of serious concern. The land and water resources management has received top priority to improve the socio-economic condition of the locals. Lack of fodder for sizable animal population was a problem having serious repercussions on land degradation.

This paper attempts to share the success model of reclaiming sodic soils through people’s participation. Impact of environmentally sound, technologically feasible, cost effective, socially acceptable and community driven silvopastoral management on an area which was extremely sodic and where profitable agriculture was not warranted but had great potential for providing fuel, fodder and timber to locals, was taken. The study area lies in North India, U.P. About 5 decades ago it was a fertile land. However due to unsustainable land use it lost it’s fertility character and thus productivity. When it’s management came under the charge of the presenter, the soil had a very high pH and exchangeable sodium and presented an appearance of greyish white efflorescence of salt on the surface. It had slow infiltration rate and hydraulic conductivity. It often developed thin cracks and became cloddy in dry conditions and sticky when wet. Most serious impediment to root development was the cemented bed of ‘Kankar’ in lower depth.

Emanating from the past experiences/actions of my predecessors ,a little departure, that involved the participatory approach was adopted. The basic strategy to reclaim the land for improvement of pastures was to ‘invest in people than in land’ This was done by motivating, training and educating locals. Consequently all forestry related activities were carried out by the locals. Due to the carelessness and ignorance among the locals, about the’ real loss’, land degradation had been increasing consistently. It prompted the need of creating better understanding among the locals about the importance of forests, forage security, fuel security, food security, ecological security and social security. Problems of locals were not addressed and there were other unclaimed reasons. The issues faced were:

a) meeting the fodder needs of the local cattle
b) meeting the fuel needs of the locals
c) checking the soil loss
d) lack of funds and infrastructure including manpower
e) bureaucratic hurdles

The best alternative thought of was “investment in people is better than any other investment”. In any of the participatory activity, for their self improvement people have to decide their needs for development in their own way, in their own place. Community participation during planning, designing and execution of silvipastoral improvement and subsequent management systems and implementation by the locals was the key to success.

Methodology

Most affected areas of the division and the competent forest guard/official with regard to pasture development were identified. Village Forest Committee(VFC) of the locals was constituted. The total number of members of the VFCs was kept at 14 plus forest guard as the member secretary. The Sex ratio was kept at 1:1(young were preferred over old). The executive committee was constituted in the following manner:-

• A forest guard or a representative of the forest department served as the member secretary who was answerable to the concerned Range forest officer.

• Three members from village panchayat who were sensitized to the menace of land degradation and willing to actively participate in all the activities leading to silvipastoral improvement were identified

• Five members from the local mahila mandal

• Five members from yuvak mandal

• After the EC is constituted Pradhan, (chairman),&Deputy Pradhan (Deputy chairman) were elected.

Operation

• To initiate the task “Shramdan”---(Voluntary Service) concept was introduced. During the ‘soilwork’ and “plantation seasons” the frequency of the meetings was made weekly where VFCs of the neighboring areas were also invited.

• Though VFCs exercised full control over the pasture improvement issues in their village however technical matters were brought at the divisional level and consulted with the presenter.

• On the day of the weekly meeting---- ‘shramdan’ full day exercise under leadership of the presenter was rendered along with the VFC and the villagers.

• In the morning stress was laid to have one to one meeting with the villagers to answer to their quarries to their satisfaction.

• After formal and informal question hour, VFC along with the villagers were led to specific area for “on the spot demo” of the methodology to be adopted for the improvement of pasturelands including ‘social fencing’----protection of the areas from grazing by the villagers themselves.

• Technique of nursery raising was demonstrated and they were encouraged to start their own nurseries

• Planting techniques, which included augur pit holes and trenches of different sizes, which were to be eventually filled with desired quantity of gypsum, farmyard manure and vermiculite were demonstrated to the villagers. During the actual operations it was observed that addition of small dose of nitrogenous and phosphatic fertilizers yielded as good results as in the case of replacement of sodic soils with normal soils which is not only costly but time consuming also.

• The villagers were taught and simaltaneous operation regarding social fencing, bio-fencing, stall feeding, soil treatment, water storage/check dams, planting of forage trees e.g.Leaucaena, Poplar, Sesbania etc, preparation of organic manure (rate of growth was evaluated and upto 65% of the increment was allowed to be removed) and rationing of fuelwood &fodder were carried out.

• Feed back from the VFCs .It became the main source of indicator of the interest of the villagers and their involvement in the activity. Enthusiasm bubbles with and resulted in chain reaction.

• After a good mental and physical exercise villagers were shown video films on wildlife and nature conservation for their relaxation.

• This exercise was repeated everywhere in the division in the different ranges.

Basically the interest of the foresters lies mainly in trees and that of the farmers in grasses. Effort was to maintain the balance between tree and fodder production. Fodder yielders (multipurpose) were preferred over timber yielders (Eucalyptus was discouraged). The increased availability of grasses from the land has direct bearing on the people’s participation in the government programs. Since if the number of trees and bushes increase disproportionately the grass yield would tend to decrease. So, the requirement of reasonable number of trees per hectare for achieving a given level of grass production was of great importance. Broadly the requirement of grass of the villages was calculated and accordingly2000 plants/hectare of different species were planted that were raised by villagers in their own ‘Kisan’ nurseries. Species such as Prosopis cinireria, Tamarix articulata, Prosopis juliflora, Acacia nilotica, Populus deltoides etc were planted. Eulaliopsis binata (bhabbar grass) was planted in the understory of these trees. Community based silvipastoral management was very cost effective as compared to the traditional methods.

Results

Survival rate at the end of third year was 60-65% and the soil analysis revealed decrease in pH, increase in the amount of organic matter and improved soil permeability. It also improved the socio-economic conditions of the locals as well as the soil environment with consequential improvement in forage production and diversity of vegetation and thus the ecological stability. Increased availability of fodder, economic consideration, social compulsions and self restraint brought dramatic changes in the animal husbandry sector. Socio-economic indicators like annual milk production in the villages increased and number of cows, buffaloes and bullocks increased. The availability of green fodder as well as dry fodder increased substantially. Further due to the increase in feed and fodder availability, migration of buffaloes and cows decreased. Reduction in grazing and migration, introduction of stall-feeding and change in the composition of the cattle population in favor of the better breeds increased the dung production in the villages. So the availability of dung for manuring and improving soil fertility also increased substantially. Thus silvipastoral improvement helped to a great extent in reducing the dependence of the villagers on fuelwood. Besides responsibility of the government gets reduced to a great extent due to the active participation of the locals.

Success parameter indicators

The success of this project could be attributed mainly to the peoples participation through VFCs for managing vegetation, soil and water resources. Besides there has been a general improvement in the standard of living of the villagers. Assets possessed by the families like sewing machines, scooters, televisions, ceiling fans were increased manifold due to the enhanced income from animal husbandry works. Area under ‘pucca’ cattle sheds, area under boundary with brick also increased. The average annual income of the whole village from all sources also showed increase. There was a sustainable improvement of vegetation in the area.

Incentives rewards and deterrents

• Appreciation letters /rewards from the department for the most effective VFC

• Scholarships to the youth for excellent participation and motivation to others

• Free ration for a week to the “best village”

As a deterrent (who indulged in anti environment practices) social and economic sanctions were imposed by the VFCs in the shape of not inviting them to community functions and ignoring them in personal terms as well .

A word of caution

Community based approach is tailored to the dire needs of a very poor and sensitive section of the society and hence need undivided attention of the department officials. But if the interest and approach of the officials remain casual or short-lived then there is little likelihood of success. Since the orthodox villagers are prone to rivalries, dedicated efforts are required to persuade people to join hands for common cause. It takes sufficient efforts of the officers to make rapport with the locals and generally it is ‘personality oriented’. So, it should be ensured that a leader of the project stays at that place for a some fixed tenure and he should also groom a deputy who should be able to take the reins of the project if the leader has to be shifted to some other place by the govt. due to unavoidable circumstances. The contractors if dragged in against the wishes of the people may naturally shake the pillars of faith.

Suggestions/gaps in information

What should be the most reasonable number of trees for optimizing bhabbar and forage grass yield has still not been experimentally worked out for different tree species and soil and slope conditions .However systematic studies are required to work out the best tree-grass associations keeping in view the twin objectives of optimizing wood and grass production as well as water yield. Inaddition,

• Marketing infrastructure

• Strengthening Extension education strategy

  Assured Maintenance funding for atleast 3-4 years

• Technical evaluation such as change in runoff, siltation loads, ground water recharge etc should be ceremoniously performed and encouraged

• The present century should be devoted to the use of forests for their indirect environmental, social and recreational functions ensuring the welfare of the locals. The need of empowering the locals and making them accountable too should be the area of thrus

Conclusion

Community based silviopastoral management seems the only sustainable and cost effective model system for the small silvopastoral holdings for the locals under joint Forest Management policy.

Advances in the implementation of sustainable livestock production systems in high mountains in Barragan and Santa Lucia, Valle del Cauca, Colombia

Walter Galindo^[49]

Introduction

This work is being carried out in the localities of Barragán and Santa Lucía in the slopes of the central cordillera of Tuluá municipality, Valle del Cauca province, Colombia. The area has an extension of 482 Km2 located bewen 2.400 and 3.500 metres of altitude, and includes an area in the Paramo biotope. The region produces 25.000 litres of milk per day that account for 69% of local incomes. An additional 29% of incomes is provided by agriculture (mainly potato, peas and carrots crops).

Dairy cattle is kept in extensive and semi-extensive grazing scheme, carrying capacity of pastures is 1 animal/ha; milk yield is 5 litres/animal/day (1.260 litres/lactation). Pastures are composed by Pennisetum clandestinum (90% of area) and improved species (10% of area). Traditional cattle grazing in the region has caused evident negative impacts on the environment, particularly due to deforestation and soil degradation.

Materials and methodology

In order to implement more sustainable practices of livestock in the region and agreement was established between DRI, COAGALBASA and CIPAV Foundation. The main goals of the agreement are:

• To develop models of sustainable cattle production in 15 pilot farms.

• To establish sustainable livestock practices as follows:

• -83 ha of pastures with electric fence for intensive rotation.

• -12 ha for silvopasture.

• -5 ha protein stock.

• -30 km of living fences.

• To train 150 farmers in the implementation of sustainable livestock for high altitudes.

• To train a locate co-researcher to help in the implementation and monitoring of the project.

Results

Table 1 shows the characteristics of the systems implemented .

Table 1. Components of sustainable livestock systems for high mountainous regions.

In order to improve the pastures already established a plough “renovador” for animal drought was obtained. It ventilate the soil and breaks the Pennisetum clandestinum rhizomes stimulating its growth.

Economic impact of subclinic mastitis in 73 herds

1. Infected animals produce 40% less milk than healthy animals.

2. Reduction in milk of 374 effected cows detected in 73 farms amounts 748 litres/day (179.520 litres/year) that worth US $ 30.192 in the market.

3. Each farmer stops to receiving US $ 414 per year.

Expected impacts

-To develop a model of sustainable cattle production for high mountains that can be applied in other regions of similar topographic conditions at both national and international levels.

-To increase milk yield in 20% during dry season.

-To create a database with information of productive and reproductive parameters of performance for local herds.

-To improve milk quality by controlling and preventing subclinic mastitis.

-To employ alternative veterinary medicine practices in order to control the most common cattle diseases in the region.

Management of natural regeneration for introduction of livestock agroforestry systems

Virgílio M. Viana^[50], Rogério M. Maurício^[51], Rodrigo Matta-Machado^[52], Ivan A. Pimenta^[53]

Introduction

Brazil has the second bovine herd in the world (160 million) and the livestock activities are an important factor to transform wild areas into pastures. Therefore it promotes the deforestation process by large tree cuttings. Nowadays, millions of hectares are destroyed per year in the Amazon forest and for most of the areas pastures are implanted. For the Atlantic Forest 93 % was destroyed and the rest is surviving as forest fragment (Viana et al., 1997). In the Brazilian Savana (total area: 180 million hectares) 120 million hectares are natural pastures which are normally abandoned after 15 or 20 years of use as pasture (Haridasan, 1987). In places where wild vegetation was changed by introduced grass, the pastures are rapid process of degradation (Lascano, 1991).

The statistical data about deforested areas in Brazil do not reflect the problem. Most deforested areas promote a production system, which is not sustainable in environmental, economical and social terms. The environment consequences are most of the times, extremely negative including erosion, CO₂ and other gases emission which contribute for the increase of the greenhouse effect and loss of the biodiversity. In addition, the culture and social aspect of the local people are affected.

The search for a sustainable agricultural production system more appropriate in terms of social and environmental is a great challenge for the agricultural sciences. The conventional environmental models due to the “green revolution” were based on the use of chemical fertilisers, forages varieties, soil mechanisation and the control of carrying capacity. The aim of the present work is to describe the management of natural regeneration of native tree species for introduction of livestock agroforestry system. This is a descriptive work and the results of this system has implications on the soil fertility, nutritional quality of the pasture, which were described by Mauricio et al. (2000).

Material and Methods

Study area

The study area was situated in Lagoa Santa in Minas Gerais State (19°, 35', 36'' S, 43°, 51', 56'' W, altitude 747m), Brazil.

Management System

The management system has been implanted since 1998. This system was based on the selective cutting of vegetation. The conventional management system is based on the systematic cleaning of the vegetation where every year one or two cuttings of all the vegetation (e.g. fodder trees) are done. In the management system adopted in this work the cutting process of the trees is the selective cutting only of the selected species.

Results and discussion

The findings of this work suggest a great cut in the maintenance and conservation costs. The most vigorous species which represent an environmental natural gift, are trimmed but not cut. This means a smaller number of cut off trees and bigger cutting interval. Secondly, it also represents a cheaper implantation of sylvopastoral system with negative costs. On the other hand the use of exotic trees for the introduction of a sylvopastoral system implies a greater cost for the farmers..

Sylvopastoral subsystem with Zeyhera tuberculosa (Bolsa-de-Pastor or Ipê Felpudo), family: BIGNONIACEAE

This system has been implanted since 1980. The natural regeneration of Bolsa-de-Pastor, which was harvested by the cattle, suggests a high nutritional value of its leaves. After reaching 3 metres the trees were not eaten anymore. However, the cattle bends the trees to eat the young blossoms. Various species were found in this subsystem (Table 1).

Table 1. Species list: Sylvopastoral subsystem with Zeyhera tuberculosa (Bolsa-de-Pastor or Ipê Felpudo

It is recommended the oriented cutting of excess trees to get 6-10 m²/plant. The rectilineal growth and the natural fall of the branches of Bolsa-de-Pastor is a fundamental characteristic in terms of wood quality and for the wood industry. And it is also recommended the cutting of the branches aiming at reducing the dead branches. The pasture growth under the Bolsa-de-Pastor shade did not represent any limitation for the grass in above mentioned density. The shade is mild and promotes the reduction of evapo-transpiration. The leaf-falling behaviour is a positive factor to reduce the competition between trees and grass for water during the dry season (Figure 1).

Figure 1. Sylvopastoral subsystem with Zeyhera tuberculosa (Bolsa-de-pastor or Ipê Felpudo)

Sylvopastoral subsystem with Myracrodruom urundeuva (Aroiera), family: ANACARDEACEAE

This subsystem has been implanted since 1982. During the natural regeneration process, the Aroeira trees were not harvest by the cattle. After reaching one meter the trees were not affected by the cattle foot. Several species were found in this subsystem (Table 2).

Table 2. Species list: Sylvopastoral subsystem with Myracrodruom urundeuva (Aroiera)

The vigorous growth is an excellent characteristic of Aroeira (Figure 2). However, the natural fall of the branches was not verified. Therefore it is recommended the cutting of branches with the objective to reduce the branches and the dead branches and also aiming to achieve 6-10 m²/plant. It is a fundamental recommendation to produce good wood quality. The pasture growth under the Aroeira trees was reasonable.

Figure 2. Sylvopastoral subsystem with Myracrodruom urundeuva (Aroeira)

Conclusion

The natural regeneration of tree species on the sylvopastoral system represents an low cost alternative for the farmers. This system is specially applied for farmers with low capacity for long term investment. Bolsa-de-Pastor and Aroeira were species with excellent characteristic for the implantation of sylvopastoral system in the study area. Several other native species have positive characteristics for the implantation of sylvopatoral system and further studies are needed. The sylvopastoral system based on the natural regeneration of tree species represent an alternative to reduce the expansion process of the agricultural border due to its sustainable aspects. Moreover this system promotes the permanence of the rural workers in the field due the high job demand in both the trimming and wood related activities. The spreading of this system should be followed by economical, social, phytotechnical, zootechnical data. Further research is also required.

Acknwoldegments

We would like to thank Dr. Iolanda Viana, owner of Hacienda Grota Funda, to CIPAV (Centro para la Investigación en Sistemas Sostenibles de Producción Agropecuaria - Colombia) and to CEBRASP (Centro Brasileiro de Apoio a Sistemas Agroflorestais Pecuários - Brasil) for their support.

References

Haridasan, M. 1987. Agroforestry systems for the cerrado region of central Brazil: potential and constrains. In: Metereology and Agroforestry. Proceedings of na international workshop on the applications of metereology to agroforestry systems, Planning and Management. AID.

Lascano, C.E. 1991. Managing the grazing resource for animal production in savannas of tropical América. Tropical Grassland 25: 66-72.

Mauricio, R.M., Viana, V., Matta-Machado, R., Pimenta, A. 2000. Avaliação de um Sistema Agroflorestal Pecuário baseado na Regeneração Natural de Espécies Arbóreas: influência da Bolsa-de-pastor (Zeyheria turbeculosa) e Aroeira (Myracrodruon urundeuva) em parâmetros de fertilidade dos solos. In: International symposium on silvopastoral systems Tropical Agricultural Research and Training Centre (CATIE), Turrialba, Costa Rica.

Viana, V. M., Tabanez, A.A.J. e Batista, J.l.F. 1997. Dynamics and restoration of forest fragments in Brazil’s Atlantic Moist Forest. (15 páginas) In: Bierregard, R. & Laurance, W. (eds) Tropical forest remnants: Ecology, Management and Conservation of Fragment Communities. Chicago University. Press, Chicago.