In this article we will discuss about:- 1. Introduction to Silvipasture 2. Silvipasture in Arid Region 3. Scope of Silvipasture in Arid Zone 4. Classification of Silvipasture.
Introduction to Silvipasture:
Silvipasture in arid region is a strategy for farm diversification and insurance against fodder scarcity, drought and desertification. The diversity in the silvipasture system involving combination of various trees, grasses and/or legumes provides multiple benefits like forage production, improved soil fertility with legumes, fuel wood supply, biofencing and erosion control. Silvipasture system is associated with complementarities in resource use, potentially involving the management and uses of natural resources.
Silvipasture have synergistic interaction with positive and greater total effect than the sum of their individual effect. Silvipasture systems present important opportunities for increasing the fodder production in arid region. This is justified by widening gap between demand and supply of fodder in arid region.
The silvipastoral system proved more effective in reducing soil pH, displacing Na+ from the exchange complex, Increasing organic carbon and available N, P and K. Improvement in soil physical properties such as bulk density, porosity, soil moisture and infiltration rate was higher in the silvipastoral system than in the agriculture system. The amelioration of alkali soils is feasible using silvipastoral systems.
The microbial biomass carbon in the soils of silvipastoral systems was significantly higher than in soils under sole plantation of trees and control systems. It is inferred by researchers that the alkali soils rehabilitated with Prosopis juliflora based silvipastoral systems for ten years can be put under cultivation of highly remunerative crops to harness the productivity potential of these soils.
Silvipasture in the form of shelterbelt and wind break reduces the wind speed and protect the field crops, livestock, roads and canal. On the basis of biomass production and improvement in soil health due to trees grass systems, silvipasture system could be adopted for sustainable management of degraded pasture and swallow lands in arid region.
Silvipasture is a type of agroforestry system with an intentional combination of trees, fodder crops and livestock on a same unit of land. In silvipasture system, the inter space between trees are utilized for cultivation of grasses/legume mixtures which provides a two tier grazing system.
The trees and grasses are raised at a suitable spacing so that both trees and grasses get equal opportunity to grow. Since the rooting and growing patterns of both the vegetation types are different, there is very little competition for resources. Over a period of time, trees recycle nutrients by leaf fall which on its decomposition enriches the soil surface. This system naturally improves the soil properties in a long term.
Production of wood, fodder and livestock in the same place, at the same time is viewed as an attractive, efficient and integrated land use management system to improve the overall production and to increase cash flow for landowners.
The goal in silvipasture systems is to optimize, rather than maximize, production of tree and fodder components. Silvipasture systems are low-input technology designed to meet the shortage of fodder from degraded lands. Silvipasture is not restricted to farm land; it is also amenable to improve rangeland, wasteland, eroded areas and degraded land, as long as access control to people and livestock is feasible.
Silvipasture in Arid Region:
Livestock rearing forms a major component of livelihood in arid zones, where silvipasture is a dominant land use system. This is due to low precipitation in arid areas (annual rainfall between 100 and 500 mm with a coefficient of variation varying from 40 to 70 %). The region is characterised by low and erratic rainfall with extremes of temperature (1-48°C), high wind velocity and sandy soils. Arid zone is very much prone to land degradation like soil erosion, wind erosion, desertification, frequent drought and soil salinity.
All this events adversely affect the life of desert dwellers and their livestock, very often making their survival, a challenge. In the absence of favourable conditions for agriculture, animal husbandry is the alternative source of livelihood for the majority of the rural population in the arid zone of India that spread over Rajasthan, Gujarat, Haryana and Jammu & Kashmir.
Farmers in arid region have been following indigenous farming system as means to combat desertification, by maintaining a crop-livestock-tree/shrubs,-human continuum. The arid land use system and agroforestry systems based on the rainfall has been reviewed by Saxena (1997). He stated that the area falling in less than 250 mm rainfall zone have grasses and shrubs as predominant vegetation, hence range/pasture development with livestock rearing is a major activity.
In areas receiving rainfall between 250-300 mm, besides grasses and shrubs, multipurpose tree species dominate along with mixed farming encompassing agroforestry system. In areas that receive more than 300 mm rainfall, mixed cropping, livestock and pasture management are main livelihood options. Besides its direct economic relevance, the trees and grass in silvipasture system bind the soil and reduce erosion by virtue of their deep root system. Leguminous trees have the ability to fix atmospheric nitrogen and convert it into the soil nitrate form which makes soil more fertile. Trees also prevent shifting of sand dunes and leaching of nutrients from soil.
Silvipasture systems in arid regions of India includes naturally occurring grasses in the region growing in community pasture land in association with indigenous shrubs and trees. The major grasses are Cenchrus ciliaris, C. setigerus, C. biflorus, Lasiurus sindicus, Dichanthium annnlatum, Panicum turgidum, Sporobolus sp., etc. The associated tree species are Prosopis cineraria, Tecomella undulata, Hardwikia binnata, Acacia Senegal, Acacia tortilis, A. luecoploea, Zizyphus mauritiana, Z. nummularia, Salvadora oleoides, S. persica, Capparis decidua etc.
Scope of Silvipasture in Arid Zone:
Grazing of livestock is a common practice in arid zone of Rajasthan as about 50 per cent of total area of western Rajasthan is available for gazing mainly for cows, sheeps and goats. The fodder deficit of western Rajasthan is estimated to be as high as 60 per cent of the demand.
The Man to livestock ratio is much higher in arid areas. There are 107 heads of livestock per 100 persons in arid zone of India as against 66 in Rajasthan state and 83 in whole country. The total livestock population in the arid zone of Rajasthan has increased about five-fold, from 10.34 million in 1951 to 57.73 million in 2012.
The total available forage and fodder is 67.90 million tons vs. a demand of 82.45 million tons, creating a fodder deficit of 11.91 million tons. Improving the fodder production in agriculture land through irrigation, fertilization and use of advanced techniques is a very expensive solution to meet the fodder demand in arid region. Silvipasture is cost effective technique that has been adopted in arid region to meet the fodder demands and to improve livelihood of people. The co-cultivation of trees and grasses has been a traditional practice in the Thar Desert. Silvipasture, in true sense, has been realized as a need of the day in arid region.
The major scopes of silvipasture in arid region are given below:
a. Food security
b. Fodder production
c. Soil conservation
d. Saline soil amelioration
e. Sand dune stabilization
f. Shelter belt and wind break
g. Biodiversity conservation
h. Carbon sequestration
i. Energy plantation
j. Biofuel production
k. Socioeconomic improvement
Classification of Silvipasture:
Silvipasture can be established either by planting trees in an improved pasture or by thinning a tree stand and planting improved forage. Special planning and tree arrangements in silvipasture allow tree and forage growth, as well as for grazing livestock in equilibrium. Based on the management and component of silvipasture several types of systems and practices can be identified.
1. Classification Based on the Management:
i. Intensively Managed:
a. Cut-and-Carry System (or Protein Bank):
The trees and grass/shrub species are grown in farm land or along field boundaries or other designated places; the foliage is lopped periodically and fed to animals that are kept in stalls, e.g. The leaves of Prosopis cineraria lopped for fodder purposes.
b. Live-Fence Fodder and Hedge Row:
The fodder trees are left to grow to develop sufficient wood so that they serve as fence posts around grazing units or in other plots, the trees are lopped periodically for fodder and for poles and posts as in the cut-and-carry system, e.g. Zyziphus sp and Glyricidia sp maintained as bio fence as well as fodder.
ii. Extensively Managed:
a. Browsing:
Foliage (especially tender twigs, stems, and leaves) and sometimes fruits and pods of standing trees and shrub were consumed by goats and camels in arid region.
b. Grazing:
Animals graze on the plants, usually herbaceous species. Only those grazing systems in which trees are present and play an interactive role in animal production (for example, by providing shade to animals, promoting grass growth, and providing tree fodder or other tree products) can be considered as silvipasture systems, e.g. Cows and sheep allowed freely to graze on grasses in silvipasture system.
2. Component Based Classification:
In arid zones, vegetation is typically sparse, and is comprised of perennial and annual grasses, other herbaceous plants, shrubs and small trees. To evade or minimize the adverse effects of frequent droughts, the native peoples in arid zones have often developed production systems by combining different components of woody perennials and grasses. People have established well-contained systems of production (silivipastoral/agrisilvipastoral/horti-pasture) that produce food to humans and fodder to livestock.
Based on the component of silvipasture system they can be classified as:
a. Silvipasture System (Forestry + Pasture + Livestock):
Tree species like Prosopis cineraria and Zizyphus numularia naturally grow along with grasses like Cenchrus ciliaris, Lasiurus sindicus and make a silvipastural system. Animals like cows, goats and sheeps are part of this farming system. This is a very good example of sustainable management of common property resources that still exist in several places. The silvipasture systems are strictly used according to the land’s carrying capacity. It is mostly fallowed in areas that receives rainfall is below 200 mm -1 yr.
b. Agrisilvipasture System (Agriculture + Forestry + Pasture + Livestock):
This is the most popular system in areas receiving rainfall between 200-400 mm-1 yr. In this system farmers grow dual purpose crops like pearl millet, sorghum, moth bean and cluster bean along with trees like Prosopis cineraria, Zizyphus numularia and Tecomela undulata, etc., for food and fodder purposes.
These trees do not compete with the crops but rather are complimentary in terms of improving the microenvironment. These trees give fodder, fuel, fruit etc. even when crop fails during drought, thus provide sustenance to the farmer during drought. The P. cineraria and Pearl millet agroforestry is well known around the arid regions of India especially in Rajasthan.
c. Horti-Pasture System (Orchards + Pasture + Livestock):
Hortipasture system is land use system where fruit and fodder production take place simultaneously. In this system the arid fruit trees like jujube (Ziziphus mauritiana), Date palm (Phoenix dactylifera ), Kejri tree (Prosopis cineraria) and Goonda (Cordia myxa) are raised and inter-cropped with arid grasses Cenchrus ciliaris and Lasiurus sindicus. It is suitable for areas receiving rainfall of more than 250 mm.
This agri-horticulture system has been found to give better and earlier production year-round and provide resilience to erratic rainfall. Besides fruits and wood from pruning (for fuel or fencing), leaves as fodder are the additional products from tree. Overall, the productivity of the system is good compared to sole crop. This system can provide better economic returns as compared to the sole cropping in arid region.