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Panel 2: Ecology (Contd.)

FODDER SHRUBS IN LIBYA

Fernando Riveros
Senior Officer, Grassland and Pasture Crops Group
Plant Production and Protection Division
FAO, Rome

1. INTRODUCTION

In 1973, The Socialist People's Libyan Arab Jamahiriya decided to improve their range and develop livestock with the object of reducing imports and achieving selfsufficiency in meat.

Rangelands, as national policy in Libya, are considered as those between the isohyets of 50 and 200 mm rainfall. Above 200 mm the arable lands are reserved for agricultural practices. Rangeland production below 50 mm is negligible.

Therefore, 17 range projects were created and well distributed from West to East along the coastal rangelands.

A rangeland program concerning the improvement of the range projects, called grazing perimeters, has been prepared and followed using several different techniques: prohibition, scarification, reseeding, soil conservation and plantation on a large scale.

The plantation of fodder shrub species had —and still has— an important place in this program aiming at the creation of fodder reserves for drought seasons.

Almost 60 thousand ha have been planted on suitable sites, mainly with Acacia and Atriplex. More than 70% of these fodder shrubs are at their optimal production stage and are now exploited by the animals.

Parallel to the large scale plantation and after a recommendation of the FAO Range Projects, about 35 species were planted in the arboretum and pastoretums (Wishtata, Wadi Sasu, South Zliten, Wadi M'rah) for experimental purposes aiming to study their performance vis-a-vis the local conditions, their palatability and their use.

The present article presents a summary of the species selection, the plantation and shrub management techniques.

2. FODDER SHRUB SPECIES

The major fodder shrubs species planted on large scale in grazing perimeters are as follows, by order of importance:

2.1 Acacia cyanophylla (Acacia saligna)

These well known species have given good results mainly on sandy deep soil dunes receiving an equivalent of 200 mm rainfall. Plantation density is between 200 and 400 plants per hectare.

Yearly production varies from 300 to 3000 kg of edible DM with an average of 800 kg/ha.

Longevity is estimated from 7 to 12 years if the species is not exploited. Regeneration is noticed only when rainfall exceeds 250 mm and where the soil is deep sandy.

2.2 Atriplex nummularia

This species is successful on deep loamy and loamy sandy soil receiving 150 mm rainfall and runoff.

Plantation density varies between 1200 to 1800 plants per hectare, and its dry matter yield is estimated between 300 and 2000 kg, with an average of 1000 kg per hectare.

Its longevity under local conditions is between 6 to 10 years. Regeneration is observed only on very exceptional sites.

2.3 Atriplex halimus

This local species is more resistant than A. nummularia to aridity, and gives good results on all types of soils, even where there is gypsum and salt. It is planted with the same density as A. nummularia. However, its production is lower, between 150 and 1500 kg of DM per hectare-year, with an average of 600 kg.

Longevity varies from 7 to 10 years, but regeneration is very good.

2.4 Atriplex canescens

This species, with different ecology than A. nummularia, has given good results, particularly on deep sandy soil and dunes.

It is planted with the same density as the other Atriplex, and its production is more or less equivalent to A. halimus. Its longevity can be estimated between 8 to 10 years, and regeneration was not noticed.

2.5 Calligonum comosum

This Saharian local species is used with success on mobile dunes and even very dry sites (less than 150 mm rainfall). Spacing is equivalent to 1300 plants per hectare, and the estimated production is about 600 kg DM/year/ha.

Its longevity is very long. However, it is only palatable to goats and camels.

2.6 Opuntia ficus-indica

This species requires more moisture, deep soil and organic matter. It was planted only on a small scale (Bir El Ghanem, Zliten) but the success was generally poor.

Density was about 1300 raquettes per hectare.

2.7 Acacia tortillis (Acacia raddiana sp tortilis)

Originally this local species was intended to be planted at a rate of 10%. However, the success was negligible due to the fast development of long root at the nursery.

It requires a special treatment and has to be kept at the nursery not more than 3 months.

2.8 Periploca laevigata

This local species was tried on small scale at the Central Zone (Bogrine, Wadi Sasu, Wadi M'rah), and the result is promising due to its resistance to the aridity. While growth at first stages is low, Periploca laevigata has been considered as a promising species in range improvement.

2.9 Other Fodder Shrubs Species

In trials testing the adaptation of fodder shrubs to the local conditions and as a preliminary indication, the following species showed promising results: Acacia victoria, Acacia saliana, Acacia aneura, Acacia farnesiana, Parkinsonia aculeata, Cassia sturtii, Prosopis juliflora and Atriplex semibaccata.

3. PLANTATION TECHNIQUES

3.1 Nursery Operations

3.2 Selection of Planting Sites

Under less than 200 mm rainfall only depression and wadis with relatively deep soil are selected for plantation.

3.3 Soil Preparation

The most widely used technique for plantation in Libya is 80 to 90 cm deep tooth ripping. In wadi beds and where there is slope, mechanical soil preparation is made along the contour lines. Disturbance of natural vegetation is always kept at a minimum to avoid erosion.

3.4 Seedling Transportation

3.5 Planting

3.6 Plantation Density

Plantation density is related to the availability of water in the soil and the species planted.

For Acacia sp, recommended spacing is 5 m × 5 m or 5 m × 10 m. For Atriplex sp, 5 m × 1.5 m in single row or 5 m × 1,5 m × 2 m double rows.

3.7 Tending

4. FODDER SHRUB UTILIZATION

The art of fodder shrub management is not well known in North Africa in general, and Libya in particular.

This is manifest in the following:

Based on the up-to-date available information derived from the work of the FAO team in Libya and their experience in the last few years, the following guidelines on the use of shrubs are presently followed:

- Acacia cyanophylla (A. saligna)

Should be utilized after 4 wet seasons by direct grazing. Periodic cutting is conducive to longevity. The usual method is by lopping at 40/80 cm above ground level every 2/3 years.

When the top branches are removed (every 2/3 years), half of remaining biomass should be anually pruned and used as feed reserve.

- Atriplex nummularia

To be used in two wet seasons after planting by direct grazing in summer and autumn, when it should have reached a height of 80 cm.

When its height is beyond the reach of small ruminants (sheep and goats), camels are introduced to contribute to the utilization of the shrub by direct grazing, or alternatively pruning at 80/100 cm above ground level in July/August or December/January. Cutting is repeated when the shrubs become woody at 50/80 cm above ground.

Atriplex halimus and Atriplex canescens

These species are utilized by direct grazing after the second season of planting. The first cutting should be done during the third year in August/September or December/January at 10/20 cm above ground level. Cutting is repeated when the shrubs become woody and inaccessible to animals.

In general, shrubs should be used mainly in the drought seasons, when range production is minimal. It should be supplemented by concentrate, or mixed with a grain ration.

CONCLUSION

The experience in large scale fodder shrub plantations in Libya is huge, and has contributed to the knowledge on the adaptability of some fodder shrub species, but knowledge on the long term production and the utilization of these plantations is still to be gained.

To realize these plans, the study of the following fields as a priority should be formulated and executed in the immediate future:

REFERENCES

BESKOK T.E. 1979. Nursery and Plantation Problems in the Gefara Plain and Jebel Nefusa Zones. FAO/LIB/010, Final Report, 98 p.

GADDES N.E. & JALEL J. 1976. Carte des zones traitées contre la desertisation - Tunésie Centrale et Meridionale. Ech. 1:1.000.000. Bull. Sols de Tunésie No8, 20 p.

FAO/LIB/011 PROJECT 1980. Specifications for Planting in Perimeters 1.1 and 2.1.3 p.

FAO/LIB/010 & LIB/011 PROJECT, Feb. 1982. Review Meeting on Rangeland Development, 6 p.

FAO/LIB/010 & LIB/011 PROJECT, Jun. 1982. Review Meeting on Rangeland Development, 6 p.

FAO/LIB/011 PROJECT 1984. Note on the Use of Cutting Machine. 2 p.

FODDER SHRUBS IN AFRICA

Fernando Riveros
Senior Officer - Grasslands and Pasture Crops Group
Plant Production and Protection Division
FAO, Rome

1. INTRODUCTION

1.1 The Dry Regions in Continental Africa

Continental Africa includes vast regions considered dry on account of being affected by severe climatic conditions, the main features of which are the low intensity and irregularity of rainfall, and the occurrence of long drought periods.

According to the dryness of the climate, the areas can be rated as semi-arid, arid and extremely arid or hyper-arid. Semi-arid regions are generally considered as those receiving an average of 400–600 mm rainfall yearly. Arid regions are those with annual rainfall ranging from 100 to 400 mm. Last, those regions with less than 100 mm average annual rainfall are rated as hyperarid or desertic.

At the areas with subtropical climate of both hemispheres rains occur, usually, in the cold season, while in the intertropical zone rainfall takes place in the warm season.

Nearly 60 per cent of the countries located in Continental Africa (47 in total) have more or less significant arid or semi-arid areas. The countries are as follows:

Northern Africa:Morocco, Algeria, Tunisia, Libya, Egypt;
Western Africa:Western Sahara, Mauritania, Senegal, Mali, Upper Volta, Nigeria, Niger;
Central Africa:Cameroon, Chad;
Eastern Africa:Sudan, Ethiopia, Djibouti, Somalia, Kenya, Uganda, Tanzania;
Southern Africa:Angola, Namibia, Botswana, Zimbabwe, Mozambique, Swaziland, South Africa.

Without taking Swaziland and South Africa into account (data unavailable), the area of the combined dry lands of the above countries is around 14 million km2, distributed as follows among the five parts of the African Continent:

TABLE 1
Dry Lands in Continental Africa (km2)

 Total Area (1)Dry Lands (2)% of total area
Northern Africa5,752,8905,538,00096.26
Western Africa6,396,1403,610,70056.75
Central Africa5,365,5501,060,00019.75
Eastern Africa6,205,3202,754,41044.39
Southern Africa (3)4,764,970      1,167,969 (3)24.51
Total28,484,870  14,131,079  49.61

(1) FAO Production Yearbook, 1982
(2) EMASAR estimates (work papers 2, 3 and 4) and Le Houérou/Popov (1981)
(3) Swaziland and South Africa not included

The more important semi-arid, arid and hyper-arid lands occur in the northern hemisphere, where the most part is occupied by the Saharan Desert and the Sahelian Zone south of this vast desert.

Tables 2 and 3 indicate respectively the dry land areas per country in Northern Africa and in Intertropical Africa.

TABLE 2
Area of Semi-Arid, Arid and Hyper-Arid Lands in Northern Africa (km2)

CountryTotal area
(*)
Semi-aridAridHyper-aridTotal% of total area
Morocco   446,550100,000120,000   130,000   350,00078
Algeria2,381,741  90,000200,0002,000,0002,290,00096
Tunisia   164,150  20,000  55,000     63,000   138,00084
Libya1,759,540    5,000  90,0001,665,0001,760,000100  
Egypt1,001,499         —  30,000   970,0001,000,000100  
Total5,753,480215,000495,0004,828,0005,538,00096

Source: FAO/UNEP EMASAR Conference, Rome, Feb. 3–8, 1975, work paper No. 4
* According to the Grand Atlas of the African Continent - Paris, Editions Jeune Afrique, 1973.

TABLE 3
Arid and Semi-Arid Lands in Inter-Tropical Africa (km2)

CountryTotal Area
(*)
EMASAR estimate
(**)
Le Houérou/Popov estimate
(***)
% of total land
Western Africa    
Western Sahara266,000 (266,000) (266,000)  100
Mauritania1,030,700(1,030,700)849,709 82–100
Senegal201,40064,000 72,803 32– 36
Mali1,240,710966,000 828,685 67– 78
Upper Volta274,20022,000 35,099 8– 13
Niger1,267,0001,211,000 2,210,970  96
Nigeria923,76851,000 3,641 0.4– 6
Total5,203,778 3,610,700  3,266,907  63– 69
Central Africa    
Cameroon475,442 48,000   3,726  0.8– 10
Chad1,284,0001,012,000 884,581 69– 79
Total1,759,442 1,060,000  888,307  50– 60
Eastern Africa    
Sudan2,505,813 1,345,000  1,471,514  54– 59
Ethiopia1,221,900725,000 447,118 37– 59
Djibouti22,000(22,000)21,990  100
Somalia637,657580,000 587,477 91– 92
Kenya583,000410,000 316,703 54– 70
Uganda243,0008,000 — 3– 
Tanzania937,70174,000 6,842 0.7– 8
Total6,153,071 2,754,410  2,851,644  45– 46
Southern Africa    
Angola1,246,700 —  119,479   10
Namibia824,292— 311,185  36
Botswana600,372600,000 319,078 53–100
Zimbabwe389,361— 64,937  17
Mozambique783,000— 72,368  9
Total3,843,725  887,047   23
Grand Total16,960,016 8,044,410  7,912,905   

* According to the Grand Atlas of the African Continent. Paris, Editions Jeune Afrique, 1973.
** FAO/UNEP EMASAR Conference, Rome, Feb. 3–8, 1975, work papers Nos. 2 and 3.
*** Le Houérou H.N., Popov G.F.. - An ecoclimatic classification of intertropical Africa, Rome, FAO, 1981.

The figures in parenthesis are from A. Naegelé.

1.2 Importance of Livestock Raising

Raising of larger livestock (cattle, camelidae) and small ruminants (sheep, goats) is a major activity in the dry regions of continental Africa.

Taking into consideration only those countries where dry areas account from 50% to 100% of the total land of the country, ruminant stocks at those countries would be as follows, as of 1982, according to statistics released by FAO:

TABLE 4
Livestock Populations in African Countries Where over Half of the Territory is Arid or Semi-Arid (millions of head)

CountryCattleBuffaloesDromedariesSheepGoats
Morocco2,900  230 14,900 6,250
Algeria1,39015013,7002,760
Tunisia6001734,500800
Libya1941355,6001,500
Egypt2,3212,447901,7001,542
Western Sahara9220148
Mauritania1,2008004,9002,650
Mali5,1341736,3507,000
Nigeria3,3504102,9007,300
Chad3,8004462,3582,358
Sudan19,2342,57018,54713,174
Ethiopia26,2001,00023,35017,220
Djibouti4354380550
Somalia4,0005,60010,30016,700
Kenya12,0006105,5005,500
Botswana3,000200700
Total85,366  2,44712,533 115,205 86,152

Source: 1982 FAO Production Yearbook (36th Ed.)

Most domestic ruminants are concentrated in arid and semi-arid regions.

1.3 Animal Production Systems

Two animal production systems prevail in arid and semi-arid regions: nomadism and transhumance. These systems are based on the extensive and maximum use of fodder produced by natural plant formations, depending on water availability for the animals. Additionally, at forested or cropped areas, livestock may benefit from fallow or tree harvesting slash.

Pastoral nomadism is a very common livestock raising practice in desert regions (less than 100 mm rainfall annually) and semi-desert areas (100–250 mm rainfall anually). The continuous movement of livestock is essential to obtain the maximum benefit from limited water and pasture resources which, in these regions, vary greatly in time and are discontinuous in space. Nomads raise mainly camels, goats and sheep. These animals are particularly well adapted to the harsh desert conditions. Nomads raising cattle are less common than those raising camels, goats and sheep; they are found more frequently at areas where rainfall exceeds 200–250 mm yearly.

Transhumance is practiced mostly in Northern Africa and in the Sahelian zone of tropical Africa. Cattle and small ruminant herds move every year, at predetermined times, from summer to fall pastures, or from rainy to dry season pastures. This movement follows routes well established by custom, known as transhumance roads or axis.

2. EXPLOTATION OF RANGELANDS WITH WOODY SPECIES

Traditionally grazed natural plant formations at arid and semi-arid regions are largely steppe formations, covering siginificant areas. Many of the steppes present mixed populations, i.e., made up of herbaceous plants —mostly short-cycle annuals—, and woody species of varied shapes: trees, shrubs, bushes and thicket. These types of plants may be differentiated as follows (according to R. Rol, 1962, cited in M. Baumer 1980):

Among the steppes covered by woody species the most relevant are:

The woody species included in the floristic composition of various steppe formations are essential for livestock raising in arid and semi-arid regions, as many of them, with their leaves, fruit or twigs provide, if not all, most of the feed during the dry months.

Woody species provide not only fodder to livestock, but also a number of products useful to desert dwellers as well (timber, fruit, medicinal products, dyestuffs, tannins, fibres, etc.). Among these collectable products, wood is in highest demand to meet fuel requirements (heating and cooking).

Besides their productive role, woody plants are effective in stabilizing soils and, therefore, preventing water and wind erosion. They provide as well organic and mineral matter to enhance soil fertility. Shade trees offer livestock shelter from the sun at the hottest hours. The presence of trees and shrubs in rangelands is both a quantitative and qualitative improvement factor of the herbaceous layer. Indeed, at the Sahelian zone is has been detected that, after the end of the rainy season, grass under trees and shrubs stays green longer than that exposed to direct sunshine, and that the dry weight of these grasses and forbs per square meter is higher under trees than elsewhere. Observations by L. Civatte, by the end of October 1946, in Northern Senegal, showed the following results:

Grass under trees:100–150 g dry weight/m2 (= 1–1.5 ton/ha)
Exposed grass:50–75 g dry weight/m2 (= 500–750 kg/ha)

In arid and semi-arid regions woody species constitute an essential element for pastoral economy, for their favourable influence on the soils and herbaceous cover, and their nitrate and mineral contributions during drought periods; additionally, the nutritive value of dry forbs is very poor. As a result of anarchic and abusive exploitation (felling of trees and shrubs, removal of bushes and thickets), woody perennials decrease in population every year. Their progressive disappearance enhances aridity and favours soil erosion, leading to desertification and a regression in pastoral life.

It is widely admitted that the main cause of the progressive decrease of the resources offered by woody species in arid and semi-arid regions is the deterioration of rangelands as a result of rapid demographic growth (2–3.5% a year), often rated as explosive. This is, in turn, due to progress in medicine and hygiene since after World War II. This growth imposes ever increasing demands on fuelwood and food obtained from cropped lands and livestock raising.

To meet the food demand of an ever larger number of people, it is necessary to put under crop production increasing areas of land through clearing of the steppes. The result is a substantial and increasingly important disappearance of the best rangelands. Finally, when all lands have been claimed for these purposes, the only lands left for livestock raising will be the less fertile stretches, more degraded or not suitable for crops. Parallel to this, the improved animal health conditions (prophilaxy of epizotic disease and improvement in treatment of parasitic ailments) over the last three decades has made it possible to substantially increase the animal stocks, despite the sizable losses caused by the third severe climatic crisis this century, which swept Africa, particularly the Sahel, between 1968 and 1973, after those of 1910–1916 and 1944–1949. Consequently, the larger animal stocks cause an intense degradation of the grazing lands presently available.

Currently, significant rangeland areas are being permanently stripped, or are on the way thereto, by irrational human practices. It was not until the 1950's that the governments of those countries with substantial proportions of arid and semi-arid lands started to worry about matters related to management, use and improvement of their rangelands.

3. ACTIONS RELATED TO WOODY FODDER SPECIES

Various specialized United Nations agencies are actively engaged in problems inherent to arid and semi-arid regions throughout the world, particularly the Food and Agriculture Organization of the United Nations (FAO), the United Nations Educational, Scientific and Cultural Organization (UNESCO), the United Nations Environment Programme (UNEP), and the United Nations' Sudanese-Sahelian Office (UNSO).

As regards FAO, particularly, with the help of UNEP, in 1975, it designed an international cooperative program, commonly known as EMASAR Program, engaged in the ecologic management of the arid and semi-arid stretches in Africa and the Near and Middle East. Within the framework of this program, it has released, among others, an important work paper (365 p.) under the name of Notes on trees and shrubs in arid and semi-arid regions, providing scientific and technical information on 74 species and two genera of woody plants, which may be employed in operations aiming at the reclamation of dry Mediterranean or intertropical regions. This document is available both in French and English.

In 1981, FAO dedicated one of its technical papers of the Plant Production and Protection Series (No. 25) to Prosopis tamarugo: Fodder tree for arid zones. This paper is available in Spanish, French and English.

In 1971, through the UNDP/FAO/TUN/11 Project (Reforestation Institute, Tunisia), FAO released a technical report with an in-depth study on Atriplex in Tunisia and Northern Africa.

In 1980 it took part in the International Colloqium on Woody Fodder Species in Africa, organized in Addis-Abeba by the International Centre for Livestock Raising in Africa (CIPEA).

FAO, to this date, has provided significant assistance to various African countries to improve their rangelands through the establishment of fodder tree and shrub plantations.

In Libya, for instance, within the framework of the FAO/TF 9496/LIB/010 and FAO/UTFN/LIB/018 Projects, considerable areas of arid lands were improved through the plantation of Acacia cyanophylla, various species of atriplex (Atriplex halimus, A. nummularia, A. canescens, A. lentiformis) and others from India (Opuntia ficus-indica var. inermis). Other plantations, of a more reduced scope, were established with several acacia species (Acacia ligulata, A. aneura, A. salicina, A. victoriae) and others, as Calligonum comosum, C. arich, C. azel, Periploca laevigata, Morus alba, Prosopis juliflora, Medicago arborea, Cassia sturtii, Colutea arborescens.

List of Shrubs and Trees Introduced in Field Project's in Various Countries

LIBYA: Projects LIB 10 and LIB 11

Range and livestock Production in the Gefara Plain and Gulf of Sirte

Trees:
Acacia farnesiana
Acacia tortilis
Acacia victoriae (Australia)
Acacia cyanophylla
Cassia sturtii
Parkinsonia aculeata

Shrubs:
Atriplex glauca
Atriplex halimus
Atriplex nummularia
Atriplex canescens
Artemisia herba-alba (native)
Opuntia ficus-indica
Periploca laevigata (native)
Rhus tripartitum

PAKISTAN: Range Management in the Sind PAK/71/001

Trees:
Acacia nilobica
Acacia senegal
Prosopis cineraria (native)
Tecoma undulata
(native)

Shrubs:
Calligonum polyonoides (native)
Ziziphus nummularia (native)

PAKISTAN: Watershed Management in the North West Frontier Province WFP Project 2451

Trees:
Robinia pseudo-acacia
Morus alba
(fodder)

IRAN: Pasture and Fodder Crop Investigations Project IRA/10

Shrubs:
Atriplex canescens
Atriplex gardneri
Atriplex nuttali gardneri
Eurotia lanata
Kochia prostrata (native)
Purshia tridentata
Spaeralcea grossularicafolia

NEPAL: Sheep, Goat and Wool Development NEP/72/006

Trees:
Bauhinia longifolia (native)
Bauhinia variegata (native)
Ficus nemoralis (native)
Litsia polyantho (native)
Leucaena leucocephala (Leguminous Species)

YEMEN ARAB REPUBLIC: Highlands Farm Development Project SF/YEM 9

Trees:
Albizzia lebbeck (from India)
Parkinsonia aculeata (fodder)
Pithecolobium dulce
Prosopis chilensis
Azadirachta indica
(from India)
Dalbergia sisoo (from India)
Tecama undulata

PDR YEMEN: Range Management and Fodder Crops Project (PDY/75/R40)

Trees:
Macula crassifolia (native)
Moringa peregrina (native)
Pithecolobium dulce (native)
Prosopis cineraria (native)
Tamarindus indica (native)
Ziziphus spina-christi (native)
Ziziphus jujuba (native)
Conocarpus lancifolius (native)
Acacia mellifera (native)
Acacia raddiana (native)
Anogeissus benthii (native)

POSSIBLE UTILIZATION OF TAMARUGO TO HELP MODERNIZE MIGRATORY ANIMAL PRODUCTION SYSTEMS

Donald L. Huss
Regional Animal Production Officer
FAO Regional Officer for Latin America and the Caribbean
Santiago, Chile

INTRODUCTION

Approximately 10% of the earth's land surface is farmed, 28% is in forests (which in part can be grazed), 15% is covered with icecaps or fresh water, leaving 47% as rangelands which are suitable only for grazing (Williams et al., 1968). These grazing lands provide the bulk of the food consumed by millions of head of domestic livestock and wildlife. Williams et al. (1968) estimated that on a worldwide average, domestic animals obtain about 75% of their nutritional needs from rangelands. This is much higher in Latin America, Africa and the Near and Middle East, where livestock obtain most of their needs from this source.

It is important that these rangelands be managed in such a way that they can be as productive as possible on a sustained basis. It is felt that the fodder trees and shrubs can play a significant role in the achievement of this goal, particularly in respect to certain kinds of rangelands.

There are many different kinds of rangelands, depending upon the climatic, edaphic, physiographic and pyric factors involved. These are normally named by the predominant kind of vegetation that gives them identifiable character such as tall, mid or short grass prairies; desert shrubs; savannah and woodland ranges, to name just a few. Native pastures can also be classified according to the only season in which they can be utilized owing to phenological growth of the vegetation and environmental conditions. Seasonal use may also be regulated by the availability of drinking water.

Consequently, there are winter, spring, summer, fall and, in the case of some mountainous areas, spring-fall rangelands. These seasonal ranges, regardless of the kind of vegetation that they produce, are of primary interest in this presentation because their utilization requires some kind of movement of livestock.

MIGRATORY ANIMAL PRODUCTION SYSTEMS

Two different kinds of migratory animal production systems are recognized, nomadic and transhumance. Nomadic grazing occurs mainly in the extremely arid and desert areas of the Near and Middle East and Africa. The pastoral nomads move continuously with their families in search of forage and water. While movements are as erratic as the rainfall, they are not haphazard wanderings as migration is usually confined within certain territorial limits (Abdallah 1978). This is a way of life which they seem to prefer (Cole 1975) and it is the only way in which the forage produced by the sporadic rainfall in these areas can be utilized.

The transhumance system differs from nomadic in that the migrations are regulated by seasonal forage availability depending upon normal climatic conditions and in some cases, agricultural practices. Transhumance grazing is a major system of livestock production in many parts of the world, such as the Guajira peninsula of Colombia and the Pacific coast of Chile and Peru, the western United States, the whole of the Near and Middle East and arid Africa. It is not only a means for producing meat, milk, fiber and leather; it is a a livelihood for millions of people.

Unfortunately, the rangelands under nomadic and transhumance grazing in the developing parts of the world are being destroyed and turned into man-made deserts through overgrazing fuel gathering and cultivation in areas incapable of sustaining agriculture. There has been a several-fold increase in livestock numbers during the past few decades in some areas (FAO, 1972). The amount of shrubs that are annually cut or uprooted for fuel is astounding. In Jordan, for instance, it has been estimated that 182 million shrubs palatable to livestock are uprooted each year for fuel (FAO, 1976). This puts man and his animals in direct competition.

Many people feel that sedentarization is the solution to these problems. However, with sedentarization, much of the forage produced on the seasonal rangelands and by the sporadic rainfall in the extremely arid areas would not be utilized. Since the demand for meat and milk is greatly increasing and since the desert and seasonal ranges can contribute to the supply, it would be unfortunate not to utilize them. Therefore, some sort of migratory grazing system is needed and for this reason nomadic and transhumance systems of livestock production do not in themselves constitute a problem. However, there is a need to modernize the systems in the developing countries so that they can become more productive and less destructive to the natural resources.

HOMING GROUNDS

While some of the concepts presented here also apply to some degree to a nomadic system, they are mainly focused upon the transhumance system. The transhumant pastoralists have “homing grounds” similar to migratory birds and animals. The homing grounds are places where they can keep their animals and themselves during the severe seasons, such as the dry or winter seasons.

They may select their homing grounds for any one of several reasons, such as fodder availability on adjoining cropland areas, housing (some own houses in villages or on farms), a habitable climate, lack of pestiferous insects (an important reason in parts of Sudan), water supply (some transport water to their homing grounds) or tradition. However, the homing grounds have one common feature, an inadequate supply of feed or poor quality feed. Thus the animals suffer and the pastoralist do not like to see their animals suffer.

A significant feature of the homing instinct is that normally several families of the same tribe occupy the same grounds. Thus homing is also a social affair. This, plus the fact that the transhumants do not like to see their animals suffer, are two features that can be capitalized upon to form the first step towards modernizing the transhumance livestock production system. This can be achieved through the creation of cooperative grazing reserves on or near the homing grounds for the exclusive use by the members.

COOPERATIVE GRAZING RESERVES

In ancient times, the groups of pastoralists or tribes in many of the African and Near and Middle East countries had grazing reserves for their exclusive use. These went by many names, such as “koze” in Kurdish or “hema” in Arabic (Draz 1983). The purpose of a reserve was to defer grazing during the wet season to establish forage for use during the dry season. The means of harvesting or grazing the forage was strictly controlled by the groups in order that the vegetation would not be destroyed. Unfortunately, most of these have been abandoned during the past 50 years or so, due to governmental programmes making rangeland public property open to grazing by all (Draz 1976).

Native pasture deteriorated by overgrazing (Syria)

Natural regeneration of desirable foraging species (Syria). This rangeland could be further improved with Atriplex or Prosopis plantations

Wide-tailed sheep under transhumant husbandry system

White camel in a typical arid rangeland in Jordan

However, the concept has been revived in the form of Hema Cooperatives in Syria (Draz 1983). The author was also personally involved in the successful establishment of cooperative grazing reserves on the home grounds of certain groups in Jordan. It is felt that the concept would be applicable to most migratory animal production systems in Latin America, Africa and the Near and Middle East. However, this would first require that the governments award a group of pastoralist, who have formed themselves into a grazing cooperative, a specific area of rangeland for their exclusive use, as was the case in Syria and Jordan.

IMPROVING THE GRAZING RESERVES

To just set aside an area of rangeland as a cooperative grazing reserve is not sufficient. As previously said, the rangelands in general are in very poor condition due to destructive grazing. While deferment during the wet season for dry season use would result in some improvement of the forage composition and production, research in many of the countries indicates that it takes several years of complete protection from grazing to attain appreciable improvements (Juneidi and Huss, 1978). Also, many rangeland areas have probably reached the point of irreversibility.

There is a need for range improvement methods that will result in rapid increases in forage quantity and quality. Since the probabilities of succesfully seeding grasses in these low rainfall areas is nil, the alternative seems to be to establish either forage trees, forage shrubs or cactus plantations. Various species of saltbrush (Atriplex) have been successfully used for this purpose in some areas, but forage productivity is often low. The spineless cactus (Opuntia) has also been used succesfully in the North African countries, but its value as a feed, other than a filler, is dubious. The search for better species must continue.

Tamarugo must be considered as a candidate for this purpose because it is native to Chile's harsh Atacama Desert, meaning that it might be adapted to other deserts as well and because of its forage, firewood and lumber producing potentials. Some examples are generalized to illustrate its potential productivities. Readers wanting more details and more comprehensive review of the literature are referred to Habit et al. (1981) and Contreras (1982).

Tamarugo is a tree that produces feed in three different forms: 1) fruit which can be hand harvested or grazed after it falls to the ground; 2) leaves and twigs which are browsed, and 3) leaves which fall to the ground as litter. About 50% of the forage is fruit and the other 50% is leaf litter. The nutritive values of the fruit and dry leaves according to analyses by Lanino (1966) are shown in Table 1. While the percent digestible protein and Total Digestible Nutrients, TDN, for the dry leaves are low, these values for the fruit are enough to meet maintenance requirements. This would be satisfactory for animals being carried over dry or winter seasons in a migratory production system.

TABLE 1
Nutritive Values of Tamarugo Fruit and Dry Leaf Samples
(Lanino 1966)

COMPONENTSLEAVESFRUIT
Composition
(%)
Digestible nutrients (%)Composition
(%)
Digestible nutrients (%)
Moisture  9,47   3,34 
Dry matter90,53 96,66 
Total protein (N × 6.25)  9,98  1.2711.14  6.07
Crude fibre10.72  2.7031.4516.22
Ether extract  1.90  0.90  1.62  0.81
Extract without nitrogen45.9117.4548.1835.72
Ash22.02   4.27 
Calcium  2.82   0.28 
Phosphorous  0.91   1.44 
TDN23.45 59.87 

Tamarugo becomes productive as far as fruit are concerned within 7 to 8 years after planting. It is known that trees of 400 or more years are still productive. The amount of fruit that is produced in Chile depends upon age, the individual tree (there appears to be variability between trees) and insect damage. The National Academy of Sciences (1979) stated that each mature tree yields up to 160 kg of pods, leaves and small twigs. Other studies indicate that fruit yields are around 1 kg per square meter of crown cover. Tamarugo plantations in Chile are used mainly for the rearing of sheep and goats, but studies have shown that cattle can also be fed. Stocking rates of 10 sheep or goats per hectare have been reported for 30 year old plantations (Habit, personal communication).

An important feature of tamarugo is that its lower branches should be pruned so that the forage on the ground can be harvested or grazed. Therefore, tamarugo plantations can be used to produce firewood as well. Contreras (1982) reported that a mature tree could produce around 500 kg of firewood. The proper use of tamarugo could be one way to help control uprooting of shrubs on rangelands.

The planting procedures for saltbrush and tamarugo are much the same, meaning that the cost would be about the same as well. Therefore, research relative to the adaptability and productivity of tamarugo in the various arid and semi-arid enviroments associated with migratory livestock production systems is highly warranted.

While this paper pertains to tamarugo, the possibilities of using ghaf (Prosopis spicigera) for establishing fodder tree plantations on cooperative grazing reserves should also be mentioned. Ghaf is a native of the Gulf and Arabian Peninsula and perhaps elsewhere in the Region. Ghaf forests growing on sand dunes have been observed in the United Arab Emirates and the author was informed that such forests existed to a much greater extent in the past than at present, and that the forests were destroyed by cutting. He was also told that the penalty for cutting a tree today is death.

Apparently, ghaf root shoots and the sprouts are eaten by livestock, at least by camels. Camels also browse the leaves and twigs. It is a beautiful tree which is planted as an ornament in many of the cities in the Peninsula. Scientific information about ghaf as a fodder tree is lacking. Consequently, adaptability and productivity research is also warranted.

RESEARCH AS AN INVESTMENT FOR THE FUTURE

If the above recommended research should prove that either tamarugo or ghaf are suitable for establishing fodder tree plantations at least in some areas, the effort and funds required to as certain this will be a good investment for the future. The transhumants' sense that they have a well larded “home” for the exclusive use by their animals is an essential first step towards their modernization. This paves the way for their acceptance of other technologies and practices required for complete modernization, increased animal production and desertification prevention.

Moreover, experience indicates that most of the people will become permanently settled, because only a select few individuals will accompany the livestock during the migration seasons. Thus, the livestock of a grazing cooperative are semi-settled but most of the people associated with it are settled. Therefore, the people become amenable to the countries' social, economical and political development programmes, such as education, health, integrated rural development and others.

REFERENCES

ABDALLAH M.I., 1978. The nomadic pastoral system and its implications in the Near East. FAO of the U.N., RNEA, Cairo, Egipt.

COLE D.P., 1975. Nomads of the Nomads. Aldine Publishing Co., Chicago. Illinois, U.S.A.

CONTRERAS D.L., 1982. Distribución, productividad y manejo de ecosistemas de tamarugo y algarrobo en Chile. Primer Simposio Brasilero sobre Algarrobo, Natal Brasil.

DRAZ O., 1976. Rangeland development in the Arabian Peninsula. EMASAR, FAO of the U.N., Rome, Italy.

DRAZ O., 1983. The Syrian Arab Republic. Rangeland conservation and development. World Animal Review No 47. FAO of the U.N., Rome, Italy.

FAO 1972. Near East regional study. Animal husbandry, production and health, fodder production and range management in the Near East and FAO's policies and plans for promoting the animal industry. FAO of the U.N., Rome, Cairo.

FAO 1976. Desert creep and range management in the Near East. Mission Rep. FAO of the U.N., RNEA, Cairo, Egypt.

HABIT M.A., CONTRERAS D., GONZALEZ R.H., 1981. Prosopis tamarugo: Fodder tree for arid zones. FAO Plant Production and Protection Paper No 25. FAO of the U.N., Rome, Italy.

JUNEIDI M., HUSS D.L., 1978. Rangeland resources of the Gulf and Arabian Peninsula countries and their managerial problems and needs. FAO of the U.N., RNEA, Cairo Egypt.

LANINO R.I., 1966. Comparación en tres razas ovinas alimentadas con tamarugo (Proposis tamarugo Phil.) (Pampa del Tamarugal). Univ. de Chile. Thesis (as cited by Habit et al., 1981).

NATIONAL ACADEMY OF SCIENCES 1979. Tropical legumes: resources for the future. Washington, D.C., U.S.A.

WILLIAMS R.E., ALLRED B.W., DENIO R.M. & PAULSEN H.A. Jr. 1968. Conservation development and use of the world's rangelands. J. Range Manage, 21: 355–360.

PROSOPIS PALLIDA AT THE SEMI-ARID BRAZILIAN NORTHEAST

Benedito Vasconcelos Mendes
Head Professor at the Mossoró-ESAM Agricultural School
Mossoró-RN, Brazil

PHYSICAL ENVIRONMENT OF THE SEMI-ARID NORTHEAST

The Semi-Arid Northeast Region of Brazil is also known by the suggestive name of Drought Polygon, on account of the periodical occurrence of such phenomena at this polygonal area.

The Brazilian semi-arid zone is located in the Northeastern Region, reaching up to the northern coast of the State of Rio Grande do Norte and the Cearan coastline. This is one of the five geographical regions of Brazil and represents as well the South American Northeast. Its geographic coordinates are 1°01'00" SL and 18°20'45" SL, and 34°45'55" WL to 48°50'15" WL.

The Drought Polygon covers a 1,150,662 km2 area, accounting for 74.30% of the Northeastern area and 13.52% of the total land of Brazil, and including 9 States in the Northeast (Maranhao, Piauí, Ceará, Río Grande do Norte, Paraíba, Pernambuco, Alagoas, Sergipe and Bahía), plus a portion of the State of Minas Gerais.

The Northeast is flat to slightly rolling, with low mountainous sectors which rarely exceed 1,000 m in altitude. The humid low mountainous areas have a so-called “altitude climate”, with cooler temperatures and more abundant rainfall, being somewhat of an oasis in the midst of the dry plain, a little similar to the humid temperate zones of the Brazilian Southeast.

The most relevant aspect of the Drought Polygon is the climate, mainly because of the occurrence of a rainfall regime which defines two sharply different seasons: a short rainy season, 3–5 months long, labelled as “winter” and occurring in the first half of the year, and a long dry season labelled as “summer”, 7 to 9 months long, stretching up to 18 months in dry years. Rains are usually heavy and irregular, both in time and space. The irregular behaviour of rainfall, both in intensity and distribution, periodically provokes prolonged droughts. Although rainfall, in absolute terms, is not low (500 mm/year on average), the water balance is markedly deficitary as a result, mainly, of high evaporation rates. The latter exceed rainfall about fourfold. The Drought Polygon's outer border is the 800 mm/year isohyet and, within it, rainfall rarely exceeds 800 mm or drops below 400 mm per year. Higher rainfall occurs at the humid mountainous areas, randomly distributed throughout the dry lands, while the lowest rainfall occurs at the Cabeceiras district in the State of Paraíba, with an average of 252 mm/year. Rainfall distribution and onset of the rainy season are highly variable, making it impossible to establish them with any degree of certainty. The yearly rainfall coefficient is a very important index for the semi-arid Northeast, as the higher values thereof are correlated with drought occurrence. This index exceeds 55% at the isohyets below 500 mm, and varies between 25% and 45% when the average rainfall exceeds this figure. Periodic droughts are characterized for the lack or inadequate distribution of rains in the “winter” season, turning water into the limiting factor for most crops and for the establishment of pastures for livestock grazing.

The Drought Polygon is one of the warmest regions in the world. Mean temperature remains more or less constant throughout the year, and is relatively uniform across the Region, ranging from 23 to 27° C. Daiy-to-night temperature difference is about 10°C, unchanged by latitude or nearness to the ocean.

Thanks to its proximity to the Equator, and to the negligible cloud cover during most of the year, mean annual luminosity is very high, staying around 2,800 sunlight hours of sunlight.

One of the greatly significant climatic factors for the Region is the extremely high evaporation occurring at the Polygon. As a consequence of the lack of cloud cover and the low latitude, solar radiation bears almost vertically upon the ground surface, favoring high temperatures which, added to the low atmospheric humidity, provoke excessive evaporation. The high evaporation coefficients come from the considerable heating of the soil, as a consequence of the intense sunlight which, besides acting directly on the evaporation, has also an indirect influence through the air movements it causes. It gives rise to hot dry winds with high mean speed (15–25 km/h). The intense evaporation, reaching an average of 2,000 mm per year, is the main factor for the deficitary water balance of the semi-arid Northeast.

Mean annual relative humidity is about 50%.

Soils, in general, are flat, stony or sandy, pH neutral or near 7, poor in organic matter content but rich in soluble minerals, particularly calcium and potassium.

The plant cover is composed of a mixture of trees and thorny shrubs, gnarled, small-sized, small deciduous leaves, and donned with a particular ability to withstand drought.

PROSOPIS PALLIDA AT THE BRAZILIAN NORTHEAST

Prosopis pallida (Humboldt and Bopland ex Willdenow) H.B.K. (= Prosopis juliflora (Sw) D.C.), is one of the most spectacular successes in species introduction at the Brazilian Semi-Arid Region.

P. pallida was introduced in Brazil in 1942, at the Serra Talhada district, State of Pernambuco, by Prof. J.B. Griffing of the old Viçosa-MG Superior Agricultural School and, in 1946, at the San Miguel Ranch, at Angicos of Río Grande do Norte, under a recommendation of the technician S.C. Harland of the Companhia Brasileira de Linhas para Coser, and from there to all of the Northeast.

This leguminous species adapted remarkably well to the soil and climatic conditions of the Brazilian Semi-Arid Region. It is grown in large scale in the States of Río Grande do Norte, Paraíba, Pernambuco and Bahía. In the last few years, as a result of the financial support from the Brazilian Forest Development Institute (IDBF) for reforestation at the Northeast, the area covered by this species has increased significantly.

P. pallida is a multiple use species, but it is as a fodder tree that it is being profusely used at the Polygon.

Pods are highly nutritious and palatable to cattle, goats, sheep, horses and other domestic animals, with a capacity for substituting maize and wheat bran in animal diets. Besides the high nutritional value of its pods, this xerophyte, which stays green and has good yields even under prolonged drought, has also the great advantage of bearing its fruit during the driest season of the year (September, October, November), when natural fodder availability is at its critical minimum. As a reforestation species it is valuable thanks to its precocity, tolerance to drought and because it yields good timber, besides giving good quality charcoal. It is also used as bee fodder. Beehives are placed inside plantations to enhance pollination and, consequently, fruit yields, apart from favouring honey production.

Recently, Figueiredo* found that carob gum can be extracted from P. pallida pods, presently obtained in large scale from Ceratonia siliqua L. and Cyamopsis tetragolonoba L. This type of gum has many applications in food technology, and Brazil could explore the possibilities of using P. pallida as source of this gum, turning from a net importer into an exporter thereof.

Besides P. pallida, the Brazilian Agriculture and Livestock Research Agency at Río Grande do Norte (EMPARN), introduced, from Argentina, Chile and Peru, four other species to be tried at the Brazilian Northeast. P. nigra and P. alba were brought from Argentina; from Chile, P. tamarugo and P. chilensis; from Peru, new P. pallida germoplasm was imported.

CLIMATE AND SOILS

P. pallida seems to grow well throughout the Brazilian Semi-Arid Region, where rainfall ranges from 252 to 800 mm per year, relative humidity stays around 50%, mean temperature ranges from 23 to 27° C, and luminosity around 2,800 hours annually.

P. pallida is not very demanding as regards type of soil, as it is found growing and thriving on different kinds of soils at the Brazilian Semi-Arid Northeast. Onaluvial soils, at river banks, it reaches considerable dimensions, with significant height and crown diameter. In general, this species grows on flat stony or sandy soils poor in organic matter and pH close to 7, typical of the Region.

PROPAGATION AND YIELD

Propagation is achieved with seeds collected from vigorous, thorn-free, straight trees with good yields of large, thick pods.

Trees blossom twice a year in Brazil, in October and June. June flowering is partial, and not all the flowers produce fruit, so that pod yield is not very high, while that in October occurs in the midst of the drought period, when all trees produce.

Mean annual pod yields per ha are in the range of 6 tons.

* FIGUEIREDO, A.A. “Lebensnittel chemischrelevante Inhaltshoffe der Schoten der Algarobeira (Prosopis juliflora DC).” Dissertation zur Erlangung des naturwissentschaftlichen Doktorgrades der Julius-Maximilians Universität Würzburg. Bayern, FRG (1975).


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