PARAGUAY

by Albrecht Glatzle and Dieter Stosiek

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1. Introduction
2. Soils and Topography
3. Climate and Agro-ecological Zones
4. Ruminant Livestock Production Systems
5. The Pasture Resource
6. Opportunities for Improvement of Fodder Resources
7. Research and Development Organizations and Personnel
8. References
9. Contacts

Paraguay is a landlocked Central South American country (Figures 1 and 2) which has common frontiers with Argentina (to the south and west), Brazil (east) and Bolivia (north). The total land area is 406,752 square km. The country is divided in two major geographical regions, with distinct topography and geology, by the south-flowing Paraguay River. Whereas the eastern region (Oriental) with 159,827 square km has an undulating landscape of rolling hills with abundant rainfall (up to 1,700 mm/year), the western part (Región Occidental or Chaco) is an extensive semi-arid to sub-humid alluvial plain with 246,925 square km (AHK 1999).
Paraguay’s population was estimated to be 5,734,139 in July 2001 and 6,506,464 in July 2006 (World Factbook 2006, July 2006 est.), of which about 98 percent are in the eastern sector; the 2006 estimated growth rate was 2.45%. More than 50 percent of the population is considered urban. Agriculture and Forestry account for 26 percent of GDP and 90 percent of exports (70 percent of which goes into the neighbouring MERCOSUR [Southern Cone Common Market] countries). Total GDP is 8,273,000,000 US $. The contribution of livestock to the GDP is 8 percent (MAG 1996).

Note: ------------ boundary of Paraguay

Figure 1: Biogeographic Provinces of South America and Location of Paraguay. Adapted from Tarso Zuquim and Lima Serrano (1997)

Politically, the country is divided into 17 Departments of which the three largest ones are part of the Chaco, whereas the 14 most populated ones belong to the Región Oriental (Figure 3).

Land tenure is unbalanced. More than 80 percent of the farmers are small holders with properties of less than 20 hectares, but they account for less than seven percent of the total farming area, whereas farms larger than 1,000 hectares (1 percent of farms) account for 77 percent of the total farm land (GTZ 1994). There are reports of farm occupations, by a growing number of landless campesinos, particularly in the Oriental sector of the country.

Figure 2: Map of Paraguay (from World Factbook 2006 Website)

Figure 3: Republic of Paraguay: Political Subdivision, Departamentos (GTZ 1994)

Landforms.Within the two main physiographic zones, the Chaco Paraguayo and the oriental region, there are further subdivisions to be featured (Figure 4):

A) The Chaco Paraguayo which comprises about 60 percent of the country, is an alluvial plain with sediments from the Andes, naturally limited to the east by the Rio Paraguay and to the south and south-west by the Rio Pilcomayo. Altitudes range between 380 m in the north-west and 80 m in the south-east, where the Paraguay and Pilcomayo Rivers join, a distance of 750 km (Ramella and Spichiger 1989). Mereles et al. (1992) distinguish two major zones of the Chaco:

• the Humid Chaco (Bajo Chaco), a plain liable to flooding, influenced by the Paraguay and Pilcomayo Rivers (annual rainfall 900 to 1300 mm);
• the Dry Chaco (Chaco Boreal) with an annual rainfall range of 400 to 900 mm, which is further subdivided into 3 major sub regions (Glatzle 1999):
• The Central Chaco is derived from a former inland delta with a mosaic of so called "campos" (old riverbeds with coarse sandy sediments) which contrast with the "monte" areas with fine textured soils (formerly temporarily inundated by flooding of the ancient river system). Campos areas comprise 15 percent of this region.
• Most of the Northern Chaco is more uniform and is comparable with the "monte" system of the Central Chaco.
• Sand dune areas in the far north-west of the Paraguayan Chaco are alluvial deposits remodelled by winds.

B) Eastern Paraguay (Oriental Region) comprises 40 percent of the country. Altitudes range from above 600 m in the north-eastern corner (Pedro Juan Caballero) and 55 m in the south-west (Pilar). The Oriental sector of Paraguay is a rather humid region of rolling hills with three major subdivisions (Bertoni and Gorham 1973):

• The Rio Paraguay Valley is an undulating lowland with plains, parts of which are liable to flooding and with a few hills or strings of hills. Almost half of Paraguay’s population live here, where the capital Asunción is located.
• The Central Plateau with many low hills forms the "continental divide" between the watersheds of the Rio Paraguay and the Rio Alto Paraná.
• The Alto Paraná Valley is an undulating plain, rising to the west. As annual rainfall is high, this zone has many large and small watercourses, all draining to the Rio Alto Paraná, which runs through a deep gorge and is dammed as the Itaipu reservoir which powers the world’s biggest electrical power plant.

Figure 4: Paraguay: Physiographic Zones (adapted from Bertoni and Gorham 1973)

Soils. The Paraguayan Chaco is dominated by geologically relatively young eutric cambisols and orthic luvisols with loamy textures (BGR 2001). Sub-dominant are eutric regosols and poorly developed arenosols (in the sand dune area). Poorly drained eutric gleysols and planosols are found in inclusions of the Central Chaco (so called "water-camps" with temporary water logging) and in the inundated areas of the Humid Chaco. As the distance from the Andes increases, soils tend to become finer in texture. The dominating soils in the Chaco have no major limitations in soil fertility, there are however big differences in water availability (drought and excess of water) over long periods (Fatecha 1989). Soil pH ranges from mildly acid to mildly alkaline.

The horizons are deep with relatively high salinity. From north-east to south-west, right across the Paraguayan Chaco, there is a belt of about 500 km long and 50 to 75 km wide with a shallow saline ground water table. This transitional zone between the Dry and Humid Chaco is prone to dry land salinity due to capillary ascension and salt enrichment at the soil surface, producing orthic solonetz and solonchaks in the "discharge area" of saline ground water. In eastern Paraguay, ferric acrisols with sandy to loamy texture are the main groups of soils in the rolling hills (Central Plateau). In contrast to the Chaco with greyish soils, for the Oriental Region a reddish soil colour is typical, due to sesquioxide formation in a rather humid environment. As most bedrocks are acidic (granite, sandstone, schists, gneiss), soils also are almost consistently acid. The depth of the soil profile and also the pedogenetic stage depends largely on its position in the relief of the landscape. Seasonally swampy, lower-lying areas in the Rio Paraguay Valley, particularly in the south-western corner (vicinity of Pilar) produce soils with hydromorphic properties (planosols). Intensively cropped basalt-derived ferric luvisols are the dominant group in the Alto Paraná Valley. Generally, the soils in the Oriental sector of Paraguay are considered to have high to medium potential for rainfed crop production (two crops a year), so long as there are no limitations of topography (steep slopes) or waterlogging in temporarily flooded areas. Contrary to the Chaco, the region has been settled and farmed for several centuries and little of the original vegetation remains undisturbed.

There is a pronounced rainfall gradient right across Paraguay. Mean annual rainfall increases from about 400 mm in the north-west to 1,700 mm in the south-east (Sánchez 1973, Figure 5). In the Chaco, about 80 percent falls in summer, whereas in the south-east corner mean monthly rainfall is more equally distributed, with a slight depression in the driest months, July and August. The growing season lasts from October to March in the Chaco. Typical crops are sorghum, cotton and groundnuts. In eastern Paraguay, arable lands are often cropped twice a year under rainfed conditions, with soybean, cotton or maize, followed by a winter crop, such as temperate cereals.

Mean annual temperatures vary from 25.9 ⁰C in the north (Bahía Negra) to 21.4 ⁰C in the north-eastern corner of the oriental region (Pedro Juan Caballero). Summers are hot, even very hot. Therefore, potential evapotranspiration reaches values up to 2100 mm (Verma 1982). Absolute maxima range from 40.8 ⁰C (Encarnación) to 44.0 ⁰C (Mariscal Estigarribia). In winter, night frosts (to an absolute minimum temperature of - 6.0 ⁰C) occur, except in the extreme north east. Aerial parts of tropical grasses are generally burnt off by frost. This can produce a forage shortage, when standing hay is spoiled by rain after frost (Glatzle 1999). Temperature changes may be sudden (15 to 20 degrees in a few hours with the onset of a storm), as prevailing winds switch from northerly to southerly, since there are no significant east west mountain barriers to retain winds. Wind speed exceeds 6 m/s for 14 percent of the year, resulting in wind erosion of cleared, bare land (Hacker et al. 1996). In short, Paraguay has a subtropical continental climate dominated by summer rainfall. It falls within the C climates of Köppen’s classification (Eidt 1969).

Figure 5: Paraguay (Chaco): Rainfall and Temperature

Vegetation. The dominant vegetation formations are xeromorphic, thorny, dry deciduous forests in the Chaco and subtropical rainforests in the East.

Dominant trees in the Dry Chaco are Aspidosperma quebracho-blanco, Chorisia insignis and Schinopsis quebracho-colorado. Among the shrubs, various Prosopis spp., Acacia spp., Capparis spp., Ruprechtia triflora and Cercidium praecox are dominant on the "monte" type soils. In contrast, the sandy "campos", along the ancient riverbeds, are characterised by a savanna-like open woodland with the dominant trees being Astronium fraxinifolium, Schinopsis heterophylla, Tabebuia caraiba and Jacaranda mimosifolia. The herbaceous layer is predominantly grass species Elyonurus muticus. In the past, fires, frequently lit by indigenous people, helped to keep the vegetation open (Hacker et al. 1996). Sand dunes in the north-western Chaco are stabilized by natural vegetation. Their pronounced topography differs markedly from the flat, sandy "campos" in the Central Chaco, but their savanna-like vegetation is very similar. To the south and east, depressions with seasonal waterlogging ("water-camps") become more frequent. Here, the trees Prosopis ruscifolia, Calycophyllum multiflorum and Bulnesia sarmienti indicate cracking clay soils. The centre of the seasonal ponds, however, have no woody vegetation. An edaphic grassland with species tolerant of waterlogging like Hemarthria altissima, Leersia hexandra and Paspalum spp. covers the ground. In the humid Chaco, the vegetation is characterised by a mosaic with the irregular distribution of wetlands. The lower areas are seasonally waterlogged savannas with a palm (Copernicia alba) and grasses like those in the "water-camps" of the Central Chaco, whereas drier areas typically support a tall Anadenanthera colubrina forest (Ramella and Spichiger 1989). In the Oriental Region, the littoral of the Rio Paraguay Valley resembles the "Entre Rios Formations" of Argentina with open swampy grasslands and marshes. This region is suitable for cattle raising. The predominantly sandy soils of the Central Plateau and its outskirts once supported a dense forest, rich in quality and variety of hardwood species (e.g. Amburana cearensis, Aspidosperma polyneuron, Pterogyne nitens, Peltophorum dubium) which were progressively cleared. Besides timber species there are yerba mate (Ilex paraguariensis) and the tung-oil trees (Aleurites fordii) as well as the "coco"-palm (Acrocomia totai) grown in pure plantations or mixed cropping systems. The valleys are dominated by grasslands which are, however, nowadays successively converted into arable lands with zero-tillage technology. The undulating plain of the Alto Paraná Valley was also once covered by species-rich subtropical forest, much of which has been converted in recent years to intensively cropped arable lands (particularly for soy bean and temperate cereals).

There are about 10,000,000 head of cattle, 400,000 sheep, 350,000 horses, 120,000 goats plus 1,800,000 pigs and some 15,000,000 poultry in Paraguay (DCEA 2000). Figures in FAOSTAT for 2005 are 9.6M cattle; 500,000 sheep; 360,000 horses; 155,000 goats; 1.6M pigs and 17.9M poultry (FAO, 2006). Hence, cattle raising for meat and milk is by far the most important livestock sector. Livestock numbers are shown in Table 1. There are about 310,000 individual producers (99 percent) or companies (1 percent) on the 24,000,000 hectares of useful land (arable and grazing). On average there are 5.3 members per producer family.

Table 1. Livestock numbers (FAO databases, 2006)

	1980	1990	1995	2000	2001	2002	2003	2004	2005
Cattle nos (,000)	5,854	8,254	9,788	9,737	9,889	9,260	10,128	9,622	9,622
Goat nos (,000)	115.0	148.2	122.6	123	124	125.5	105.5	159.5	155
Sheep nos (,000)	380	457	386	402	406	410	423	525	500
Horse nos (,000)	310	334.6	410.9	400	358	358	360	360	360
Pig nos (,000)	955.5	2,444	2,525	1,800	1,804	1,365	1,474	1,507	1,600
Poultry nos (,000,000)	12.4	17.6	14.9	16.1	16.2	16.3	17.7	17.9	17.9

Land and Livestock Tenure. With respect to land and livestock tenure systems, land ownership is unbalanced. Farms between 1 and 20 hectares own less than 15 percent of the livestock and represent more than 70 percent of all producers / producer families. On the other hand, the producer class with more than 1000 hectares (1 percent of the farms) owns 77 percent of the farm land and 60 percent of the livestock population (Table 2).

About 25 percent of Paraguay’s producers are involved exclusively in crop production. Of the rest, 89 percent run mixed farms (Molas et al. 1996), combining, meat or milk production and crops, to diversify activities and minimize risk. The remaining 11 percent are exclusively livestock producers. Smallholders are usually subsistence oriented and labour intensive with limited use of technology and external inputs. However, farms at all production levels are commercially orientated, obviously with increasing market orientation, as the farm size gets bigger. Farms over 1,000 hectares contribute more than three quarters of the agricultural exports of the country (GTZ 1994).

Table 2: Land tenure system in Paraguay as analysed by most recent agricultural census (MAG 1992)

The most striking difference between farming systems in eastern Paraguay and the Chaco is average farm size and average stock number per farm (Table 2\3). Whereas in the sparsely populated Chaco (1 inhabitant per 2 sq. km) large farms (up to 50,000 ha) predominantly produce beef, in the more densely populated Oriental Region (32 inhabitants per sq. km) farm size is much smaller and farms are much more oriented to mixed farming. Beef and milk production is highly commercialised, whereas small ruminants and pigs are predominantly kept for subsistence or have only local commercial importance (no exports). Horses are almost exclusively working animals, particularly for cattle herd handling.

Table 3: Distinctive characteristics of farms in the Oriental Region and the Chaco
(MAG 1992 and DCEA 2000)

There is practically no permanent housing of ruminants. Steer fattening in feedlots has shown marginal profitability. Animals are ranched on natural or improved pastures. Even in intensive dairy systems milking cows gain part of their feeding requirements on pastures near milking pens. Tethering is common among smallholders and landless campesinos, otherwise they keep their animals on public land between the fences at both sides of public roads. Stocking densities on range, bush land and sown pastures vary from about 10 (Alto Paraguay) to 0,2 ha (Central Department) per head of cattle, depending on the agro-ecological conditions and feed and supplement availability.

Paraguay has a multicultural rural population with strong minorities (native Indians of at least eight different ethnicities and languages, groups of settlers of Brazilian, German or Japanese origin and foreign investors) which differ considerably in their production systems, production levels and organizational structures. While the native Indians live predominantly by subsistence agriculture on communally owned land, most of them showing little affinity for animal husbandry, typical Paraguayan campesinos and foreign groups of settlers generally apply mixed farming systems on privately owned land, being predominantly market oriented. Foreign investors, representing a fairly high proportion in the Chaco (Table 3), are exclusively commercially oriented and frequently grow monocultures, such as beef, soy bean or cotton.

The organizational structure of Paraguayan campesinos and foreign investors is relatively weak. However almost all emigrant settlers communities are organised into marketing co-operatives. Among them are so called "colonies" of Japanese and Mennonites (a religious community of German origin which settled in the Chaco and in eastern Paraguay mainly in the first half of the past century). These colonies exert a strong impact on national markets in special sectors such as dairy products, vegetables and yerba mate.

Herd Productivity and Breeds. Beef is commonly produced in extensive systems on the 165,000 square km of native pastures and grazed bush land plus 33,000 square km of cultivated pastures. Main capital investments refer to fencing, establishment of herd handling facilities, construction of dams or so called "Tajamares" (basins for rain water collection) and pasture establishment and maintenance. Traditionally, there was little veterinary care and infrequent herd mustering, no seasonal bull service, no weaning control and little genetic improvement. Therefore, traditional herd productivity is low compared to production figures which are regularly achieved nowadays by a growing number of cattle farmers (Table 4).

Table 4: Comparison of traditional and present production parameters of beef cattle herds and grazing lands in the Chaco (Glatzle, 1999)

The energy efficiency of forage was modelled on the basis of the production parameters of both traditional and modern systems. The improved herd productivity results in almost twice as much liveweight being produced from a unit of fodder energy consumed. Moreover, up to a tenfold rise in liveweight production per area (across the whole herd) is achieved by improving the forage base. Hence, improved pasture establishment results in a better land use efficiency (Table 4) as long as the production system is ecologically compatible. More efficient beef production technologies are increasingly adopted by cattle farmers, as indicated by an increase by 66 percent of the nation-wide extraction rate in the past 20 years (Table 6).

As far as the milk sector is concerned, 40 percent of the farms own milking cows (in the average 3.6 per farm). Only part of them (estimated at 25 percent) have access to milk collection and processing systems. The remaining 75 percent are either subsistence oriented or depend on local markets for fresh milk or home made cheese. There is a big variation of production levels, taking into account all (not only the commercial) milk producers. Whereas the nation-wide average production parameters are poor, specialised commercial milk producers achieve remarkably high production levels (Table 5) applying high technology, and covering up to 75 percent of the daily feed requirements with concentrates and silages, in order to raise milk yields and to achieve a more balanced production across the seasons.

Table 5: Milk production parameters in Paraguay comparing the national average with data from a commercial farm and a Mennonite co-operative (Molas et al. 1996)

The Criollio breed, derived from Spanish and later British cattle importations, is a well adapted, small framed and robust, double purpose breed, highly fertile but otherwise low in production. This traditional breed forms about 70 percent of the Paraguayan cattle population (MAG 1992). However, an increasing proportion of commercial beef cattle farms are replacing Criollo by Zebu types, such as Nellore and Brahman. Frequently a high level of Zebu-genes is maintained in the herds, served by bulls of British (Angus, Hereford) or European continental (Gelbvieh, Fleckvieh, Limousine) breeds in order to produce a fast growing, environmentally adapted and resistant industrial cross. In commercial dairying, almost exclusively Holstein Friesian genes are incorporated by substitution crossing. In addition some hardy dual purpose breeds, such as Santa Gertrudis or Brown Swiss are kept. Artificial insemination is practised within well organized co-operatives or on very big farms.

Production, Marketing and Consumption of Animal Products. Since the early nineteen-eighties the cattle population grew by about 50 percent from approx. 6,500,000 to almost 10,000,000 (MAG 1992 and DCEA 2000). In the same period, beef and milk production more than doubled, and indicators of production levels, such as average extraction rate of slaughter animals and milk yields per milking cow, increased by about 65 percent and 25 percent respectively (Table 6). These higher production levels can be attributed to better herd handling, improved veterinary care and the use of adapted and productive breeds, but also to the expansion of the area sown to improved pastures. Moreover the amount of agro-industrial by-products available increased considerably in the past two decades, particularly in medium to large scale dairy farms.

In 2000, total agricultural imports reached a value of US$ 383,241,000 and exports a value of US$ 647,699,000 (FAO 2005) by 2003 figures were US$ 207.7 for imports and US$ 1.02 billion for exports. Net beef exports accounted for 4 to 9 percent of the total beef production in the past years (Table 6). Beef exports vary from year to year and depend very much on the outbreaks of Foot and Mouth Disease and a positive immunological status of the animals due to compulsory vaccinations; meat exports beyond South America are insignificant. Beef imports are negligible, like imports and exports of other meats. Almost all wool and hides are processed locally or discarded.

There is only commercial milk production where an efficient and reliable collection system and a processing plant have been built up. This is the case in the Central Department (around the capital Asunción) with about 1,000,000 inhabitants, in the Boquerón and Presidente Hayes Departments (Chaco) and the Departments Caaguazú and Alto Paraná (Oriental Region). Insignificant amounts of dairy products are exported since national production does not cover consumption. Imported milk equivalents (predominantly from Argentina) account in recent years for 7 to 13 percent of the national production of commercialised milk (Table 6).

More than half of the meat consumed is beef. As stated in Table 6, total meat consumption is high in Paraguay. On the other hand the supply of processed milk is unsatisfactory (less than 2/3 of the 150 kg/head/yr. recommended by the FAO).

Table 6: Paraguay statistics of production, exports and consumption of animal products and important agro-industrial by-products used as animal feeds (FAO 2006)

¹ Sources: MAG (1992), DCEA (2000) and FAO (2006)
² Only commercialised milk
³ Bran yield: about 25 percent of wheat production - wheat exports
⁴ Seed cakes (production - exports) of soy bean, cotton, sunflower and groundnuts
n.r. = no record

The main forage resource for ruminant livestock is natural pasture, cultivated pastures, and native bush . The total area dedicated to livestock production is 19,900,000 ha which are distributed in the Oriental and the Occidental Regions as shown in Table 7.

Table 7: Areas (millions of hectares) of native and cultivated pastures and extensively grazed bush land in Paraguay (Molas et al. 1996)

Native Grazing Resources in Eastern Paraguay. Most of the grazing lands in the Oriental Region are marginal for agriculture due to natural constraints such as poor drainage, shallow soils, and rocky soil . Basically there are two types of native pastures in Eastern Paraguay.

• Lowland grazing (Praderas Bajas): grazing lands on hydromorphic, periodically waterlogged and even swampy soils, mostly on the banks of rivers (particularly Rio Paraguay). However, there are also extended stretches of plains with hydromorphic planosols with an impermeable clayey subsoil towards the central Oriental Region along riverain zones. Within these grazing lands, the dominant herbaceous species are large tussock grasses generally with low palatability and nutritive value Sorghastrum agrostoides, Panicum prionitis, Andropogon lateralis, and A. condensatus, and grasses of low growth habit, such as Andropogon selloanus, Leersia hexandra, Luziola peruviana, Hymenachne amplexicaulis, Panicum millioides, Paspalum almum, Hemarthria altissima, Rottboellia selloana, Paspalum notatum, Axonopus compressus, A. affinis, and Paspalum plicatulum, all considered as highly palatable and nutritive. Moreover, herbaceous legumes such as Desmodium canum, Aeschynomene americana, Macroptilium lathyroides and Arachis spp. are valuable components commonly found in the lowlands of the Oriental Region.
• Hillside grazing (Praderas Altas): These are grazing lands in the rolling hills of eastern Paraguay, predominantly at sites, sub-optimal for cropping in the Central Plateau and the Alto Paraná Valley. Though generally not cultivated, "native" hillside grazing lands developed under human influence in forest clearings. Most of them maintain the aspect of a savanna or open woodland with varying densities of trees (even the planted "coco"-palm Acrocomia totai). In the Central Plateau, grazing lands are often restricted to sandy soils with rocky outcrops (granite, sandstone, schist) and of limited fertility (high acidity, high aluminium and low phosphorous contents). In the Alto Paraná Valley, fertility characteristics of the basaltic soils are better, however, grazing lands frequently present slopes marginal for agriculture. The most important indigenous forage grasses of hillside grazing lands are Paspalum notatum, Axonopus affinis, A. compressus, Paspalum plicatulum and Andropogon lateralis. Common valuable native legumes are Chamaecrista rotundifolia, Stylosanthes guianensis, Arachis spp., and Alysicarpus sp.. Among the grasses of low stock acceptability are Imperata brasilensis and Aristida spp.. Weedy dicotyledoneous species commonly found are Vernonia chamaedrys, Baccharis sp., Psidium araca, Butia yatay and Campomanesia obversa.

Native Grazing Resources of the Chaco Region. The Occidental (Chaco) Region is an extended alluvial plain with a gradient of rainfall and soil texture from north-west to south-east (more rain and finer texture as the distance from the Andes Mountains increases). The agro-ecological conditions are good for permanent pastures. However cropping faces some limitations and risks from the quantity and distribution of rainfall (Dry Chaco) and temporary waterlogging (Humid Chaco) respectively (Figure 4). The native grazing resources in the two major physiographic sub regions of the Chaco can be described as follows:

• The Humid Chaco (Bajo Chaco): The grazing lands of the Humid Chaco are predominantly palm savannas with Copernicia alba on poorly drained, hydromorphic gleysols and planosols. The palm Copernicia tolerates fires and temporary waterlogging. It is found in densities of up to 100 trunks per hectare and its spread is promoted by livestock (Degen 1996). These natural grazing lands contain many grasses of medium to high nutritive value and palatability, such as Leersia hexandra, Hemarthria altissima, Panicum elephantipes, Diplachne uninervia, Hymenachne amplexicaulis, Paspalum lividum, P. alcalinum, P. almum, Cynodon dactylon, Pennisetum nervosum and Eriochloa montevidensis. Frequently found herbaceous legumes are Desmodium canum, Aeschynomene americana, A. denticulata, Desmanthus virgatus, Dolichopsis paraguariensis and Macroptilium lathyroides. Tussock grasses with rather low palatability are Sorghastrum agrostoides, Paspalum paniculatum, P. plicatulum and P. conspersum. Reported carrying capacities are one American Livestock Unit (454 kg LW) per 2 to 4 ha (Ramírez and Laneri 1989). Besides mechanical or chemical treatments or burning of the shrubby weeds (Acacia curvifructa, Prosopis ruscifolia and Geoffroea decorticans, and Tessaria dodoneaefolia), there are practically no interventions for the maintenance of good grazing economically feasible or necessary (Glatzle 1999).
  Periodically and episodically flooded areas with waters from the Pilcomayo river in regions with rather low rainfall (below 750 mm) are to be considered as a transitional zone between the Humid and the Dry Chaco. This zone along the left side riverbanks of the upper Picomayo-river is exposed to an extremely varying water regime, which may cause seasonally flooded grasslands to be reconverted into xeromorphic bush and vice versa within a few consecutive years.
• The Dry Chaco: Traditionally the most important natural grazing resource in the Dry Chaco are the "espartillo" grasslands ("campos") on the regosols or arenososls in old riverbeds of the former inland delta which shaped the landscape of the Central Chaco. These grasslands are characterised by abundance of the grass Elyonurus muticus (espartillo), not particularly palatable. Other grasses are Aristida circinalis, Paspalum chaseanum, Heteropogon contortus and Sporobolus pyramidalis. The espartillo-grasslands present a wealth of native legumes as soon as fire frequency is reduced and disturbance by grazing increased. Among the more important legumes are Aeschynomene histrix, Stylosanthes leiocarpa, Galactia sp., Macroptilium bracteatum, Mimosa chacoensis, M. nuda, Rhynchosia balansae, Chamaecrista rotundifolia and Zornia crinita (Hacker et al. 1996). Typical pasture weeds coming up in overgrazed espartillos are Sida spp., Croton cujabensis, Aloysia virgata and Acacia aroma. In former decades, a relatively high proportion of the campos was used for cropping by early European settlers and indigenous horticulturalists. Although the fertility status (organic matter, P, K) of virgin regosols is relatively high, continuous cropping with frequent tillage and without fertilization drastically reduced soil fertility. Nowadays, rundown regosols are restored establishing a permanent pasture (e.g. with Pangola grass) and introducing a suitable legume (e.g. Stylosanthes hippocampoides or Alysicarpus vaginalis).

Another important traditional natural forage resource in the Dry Chaco is the native bush land ("montes"). Browsing the mostly thorny woody plants, such as Acacia praecox, A. aroma, Caesalpinia paraguariensis, Ruprechtia triflora, Capparis tweediana and C. retusa and eating the pods of various Prosopis and Acacia spp. (Morello and Toledo 1959) supports an average stocking density of about one bovine animal unit to 10 to 15 ha of bush (Fretes et al. 1969). Understorey grasses are virtually absent: Setaria globulifera, S. fiebrigii and Digitaria sacchariflora are practically the only grasses found, but in very low frequency. There are studies demonstrating a severe degradation of the "monte" soils due to overgrazing under traditional grazing regimes. However, Adámoli et al. (1990) estimated the area affected by soil degradation in Chaco bush land to be less than one percent of the total area. Abril and Bucher (2001) reported that soil organic carbon losses are much lower under cultivated pastures than in over utilised bush land.

6. OPPORTUNITIES FOR IMPROVEMENT OF FODDER RESOURCES

Sown Pastures with Introduced Forages. The establishment of pastures with selected grasses and legumes on cleared land raises herd productivity per unit area about ten fold (Glatzle and Cabrera 1996, and Table 3). Hence it is not surprising that the area of cultivated pastures increased five to six fold since 1980, mostly at the expense of native forests and bush. Large scale land clearing and pasture establishment obviously has adverse effects on landscape and species diversity and carbon sequestration. Therefore it is indispensable to take into account a number of land clearing regulations in order to maintain or create a healthy and diverse agro-ecosystem. A steadily increasing number of farmers leave at least 25 percent of the forest, woodlands or bush of a property intact (Ley Forestal 422/73).

7. RESEARCH AND DEVELOPMENT ORGANIZATIONS AND PERSONNEL

At present little research is carried out actively in Paraguay in the fodder and pasture sector. However, in the past, international or bilateral programmes and projects introduced and screened pasture species, initiated trials on pasture and herd handling and grazing management, and disseminated innovations in the forage and livestock sector. For example:

• an American agronomist employed by the MCC (Mennonite Central Committee) who introduced buffel grass and initiated pasture cultivation in the Chaco
• the "Servicio Técnico Interamericano de Cooperación Agrícola (STICA)" who evaluated for the first time cattle breeds, native and introduced to Paraguay
• a Swiss project in connection with the "Instituto Agrario Nacional (IAN)" in Caacupé
• a USAID project in connection with PRONIEGA ("Programa Nacional de Investigación y Extensión Ganadera") in Pozo Colorado
• a French project in connection with the Fondo Gandero in La Patria
• a German project in co-operation with DIA (Dirección de Investigación Agrícola) in the Central Chaco (Estación Experimental Chaco Central, Cruce de los Pioneros).

Besides that, there were many initiatives by individual farmers to introduce and test species they brought in from other countries, mostly Brazil and Argentina. Most of the Brachiaria species and a number of Cynodon cultivars came in through this channel and were spread from farmer to farmer.

More recently, livestock farmers interested in applied experimentation became privately organised in the "Consorcio Ganadero para la Experimentación Agropecuaria (CEA)". CEA holds a highly appreciated international congress on technology transfer every year in Asunción at the headquarters of the "Asociación Rural del Paraguay (ARP)". CEA members even organised an information travel of farmers to Queensland, Australia, from where a lot of new ideas and aspects on cattle breeds and grass cultivars came into the country. Moreover, the ARP is the organiser of a big annual Agricultural Trade Fair, where regularly cattle breeds and adapted pasture seed are exposed and marketed. On a regional level, farmers conscious of sustainable and profitable production systems organise themselves in so called CREA-groups ("Consorcio Regional de Extensión Agropecuaria"). Some private CREA groups work very efficiently, and sometimes contrast favourably with public extension services, such as divisions of the Ministry based "Dirección de Extensión Agrícola y Ganadera (DEA)" or even services offered by credit institutes, such as CAH, BNF and Fondo Gandero. Only about one in ten farms is reached by a pubic extension service at a nation-wide average (Molas et al. 1996). However, many producers’ co-operatives provide competent technical assistance to their members.

A new programme has started in October 2001 at Loma Plata, Chaco, the "Iniciativa para la Investigación y Transferencia de Tecnología Agraria Sostenible (INTTAS)", initiated by the private foundation DeSdel-Chaco ("Fundación para el Desarrollo Sostenible del Chaco"), and sponsored by the Swiss foundation AVINA ("Acción para la Vida y la Naturaleza"). This programme integrates, co-ordinates and complements the on-farm-experimentation and technology dissemination activities carried out by various co-operatives and their extension services, and private farmer groups within the Paraguayan Chaco. Furthermore, INTTAS is to reactivate a virtually paralysed public research station in the Chaco Region, implementing joint research programmes, and to promote regular exchange of experience with private and public entities of interest from the other Chaco countries, Argentina and Bolivia.

The "Dirección de Investigación Agrícola (DIA)", part of the Ministry of Agriculture, carries out research mainly in the cropping sector in 9 research stations spread over the country. However, little importance is given to research in pastures and forages. The mandate of another Ministry-dependent research unit, the "Dirección de Investigación de Producción Animal (DIPA)", is to conduct research in the animal production sector in three stations across the country. Again, the products of co-operative based and other private initiatives on animal breeding, animal selection and improvement of herd handling are more obvious than public efforts in this field. The low efficiency of public research in Paraguay is primarily due to the lack of operational funds. More than 80% of the small budgets available (including revenues generated on the research stations) are used to cover the personnel costs.

In contrast to many other countries throughout Latin America efforts to revamp public-sector agricultural research and development agencies in Paraguay have yet to come to fruition. Major change was proposed in the mid-1990s in the form of the establishment of a national agricultural research institute, the Paraguayan Institute of Agrarian Technology (IPTA), as a joint public-private venture with multiple funding sources. The proposal for the creation of IPTA is still pending, however, and it now appears that no legislative decision will be made until at least 2002, following a public reform process that is currently underway in Paraguay Beintema et al. (2000). On the other hand meanwhile, a strong negative selection process is being observed, by skilled technicians and scientists moving away from the public sector (DIA and DIPA) into private research and development entities.

Some kind of extension work and small scale experimentation in the forage and livestock sector is done by institutions of higher education which are:

• Facultad de Ciencias Agrarias (FCA) - Universidad Nacional de Asunción (UNA)
• Facultad de Ciencias Veterinarias (FCV) - Universidad Nacional de Asunción (UNA)
• Facultad de Ciencias Agrarias (FCA) - Universidad Católica "Nuestra Señora de Asunción" (UCA)
• Facultad de Ingeniería Agronómica Ciencias Agrarias (FCA) - Universidad Nacional del Este (UNE)

Distinguished Technicians currently engaged in public or private research programmes in the pasture and forage sector are:

Abril, A. and E.H. Bucher (2001): Overgrazing and soil carbon dynamics in the western Chaco of Argentina. Applied Soil Ecology 16, 243 - 249

Adámoli, J., E. Sennhauser, J.M. Acero and A. Rescia (1990): Stress and disturbance: Vegetation dynamics in the dry Chaco region of Argentina. Journal of Biogeography 17, 491 - 500

AHK (1999): PARAGUAY. Deutsch-Paraguayische Industrie- und Handelskammer, Asunción, Paraguay

Beintema, N.M., P. Zambrano, M. Nuñez, and P.G. Pardey (2000): Agricultural R&D in Paraguay: Policy, Investments, and Institutional Profile. International Food Policy Research Institute, Washington D.C.

Bertoni, G.T. and J.R. Gorham (1973): The Geography of Paraguay. In J.R. Gorham (ed.). Paraguay: Ecological Essays. Academy of the Arts and Sciences of the Americas, Miami, pp. 9 - 18

BGR (2001): Proyecto Sistema Ambiental del Chaco. Inventario, evaluación y recomendaciones para la protección de los espacios naturales en la Región Occidental. Bundesanstalt für Geowissenschaften und Rohstoffe, Hannover

DCEA (2000): Síntesis Estadística 1999/2000. Dirección de Censos y Estadísticas Agropecuarias, Ministerio de Agricultura y Ganadería, Asunción, Paraguay

Degen, R. (1996): Dinámica poblacional de Copernicia alba Morong "Caranda’y". Dirección de Ordenamiento Ambiental and Estación Experimental Chaco Central (unpublished report)

Eidt, R.C. (1969): The climatology of South America. In E.J.J. Illes, H. Klinge, G.H. Schwabe, and H. Sioli (eds.). Biogeography and ecology of South America. Vol. 1. Dr. W. Junk, The Hague

FAO (2006): Online Statistical Database. http://apps.fao.org

Fatecha, A. (1989): Present and potential area for agricultural use in the Arid Chaco of Paraguay. In M. Hump and M.A. Tiefert (eds.). Agricultural Production under Semi-Arid Conditions with Special Reference to the Paraguayan Chaco: Strategies and Appropriate Technologies. DSE Feldafing, pp. 26-49

Fretes, R., C. Gay and R. Samudio (1969): Las praderas naturales del Paraguay. I. Clasificación y caracterización. Programa Nacional de Investigación y Extensión Ganadera. Publicación No. 6, San Lorenzo

Glatzle, A. and A.J.N. Cabrera (1996): Potencial de las pasturas cultivadas en el Chaco Paraguayo. In Consorcio de Ganaderos para Experimentación Agropecuaria (ed.): CEA ’96; Forrajes. III^er Congreso Internacional de Transferencia Tecnológica Agropecuaria (17 y 18 de Nov. 1996), Asunción, 155 - 168

Glatzle, A. (1999): Compendio para el Manejo de Pasturas en el Chaco. Edición El Lector, Asunción, Paraguay

Glatzle, A., R. Schultze-Kraft, and R. Mitlöhner (2001): Potential Role of Native Bush in the Chaco for Mitigation of Dryland Salinity in Grassland. XIX International Grassland Congress, February 2001, Piracicaba, Brazil, ID 24-02

Gorham, J.R. (1973): The Paraguayan Chaco and Its Rainfall. In J.R. Gorham (ed.). Paraguay: Ecological Essays. Academy of the Arts and Sciences of the Americas, Miami, U.S.A., pp. 39 - 60

GTZ (1994): PARAGUAY. Perfil del país con informaciones y comentarios relacionados al desarrollo económico y social. Deutsche Gesellschaft für Technische Zusammenarbeit, Eschborn, Germany

Hacker, J.B., A. Glatzle and R. Vanni (1996): Paraguay - a potential source of new pasture legumes for the subtropics. Tropical Grasslands 30, 273 - 281

MAG (1992): Censo Agropecuario Nacional 1991. Ministerio de Agricultura y Ganadería, Asunción, Paraguay

MAG (1996): Lineamiento Estratégico para el Desarrollo del Sector Agropecuario y Forestal. Ministerio de Agricultura y Ganadería, Asunción, Paraguay

Mereles, F., R. Degen and N. Lopez de Kochalca (1992): Humedales en el Paraguay: Breve reseña de su vegetación. Amazoniana 12, 305 - 316

Molas, O., R. Heyn and R. Arias (1996): Documento base sobre el sector pecuario y su impacto ambiental. ENAPRENA, Asunción, Paraguay

Morello, J. and C. Saravia Toledo (1959): El Bosque chaqueño. II. La ganadería y el bosque en el Oriente de Salta. Revista Agronómica del Noroeste Argentino 3 (1-2), 209 - 258

Ramella, I. and R. Spichiger (1989): Interpretación preliminar del medio físico y de la vegetación del Chaco Boreal. Contribución al estudio de la flora de la vegetación del Chaco. Candollea 44, 639 - 680

Ramírez, E.G. and J.L. Laneri (1989): Fodder and Feeding of Cattle in the Paraguayan Chaco. In M. Hump and M.A. Tiefert (eds.). Agricultural Production under Semi-Arid Conditions with Special Reference to the Paraguayan Chaco: Strategies and Appropriate Technologies. DSE Feldafing, pp. 139-148

Sáchez, T.F. (1973): The climate of Paraguay. In J.R. Gorham (ed.). Paraguay: Ecological Essays. Academy of the Arts and Sciences of the Americas, Miami, U.S.A., pp. 33 - 38

Stosiek, D., A. Glatzle and R. Schultze-Kraft (1997): Utilized Metabolizable Energy and Its Impact on the Management of Grass Pastures in the Central Chaco of Paraguay. Proc. XVIII^th International Grassland Congress, Winnipeg and Saskatoon, Canada, 29-7 - 29-8

Tarso Zuquim, P. and I. Lima Serrano (1997): Tuiuiú: Under the skies of the Pantanal. Empresa de Artes, São Paulo, Brazil (work sponsored by Monsanto do Brazil)

Verma, G.P. (1982): Research needs for the development and improvement of dryland agriculture in the Paraguayan Chaco. Unpublished report of the Technical and Economic Co-operation between the Government of the Republic of India, New Delhi, India and the Government of the Republic of Paraguay, Asunción, Paraguay

World Factbook (2006). CIA World Factbook 2006 - Paraguay.