Showcase for low rainfall areas in India
By Arun Sharma
Part 1 of 3.
A two hectares Model Organic Farm (MOF) plot was established in 2008, as part of the research farm at the Central Arid Zone Research Institute (CAZRI), Jodhpur. The plot was certified as organic in 2011.
India’s low rainfall areas (which receive less than 500 mm/yr of rain) cover about 45 million ha (approximately the size of Sweden). They are mostly found in Rajasthan (12 districts) and small parts of Gujarat, Andhra Pradesh, Haryana and Tamil Nadu. The low rainfall is erratically distributed and there are frequent droughts – which can cause economic uncertainties for local farmers. This condition is being further aggravated by climate change. It is expected that the impact of climate change by the end of the 21st Century will be greater in India’s low rainfall areas than in the country’s semi-arid or sub-humid regions.
Traditionally farms in these low rainfall areas are mixed, combining annual and perennial crops with livestock rearing. This (by default) ‘organic’ system is based on returning crop residues and manure to the soil. Although this is a sustainable farming system under the existing climatic uncertainties, its productivity is generally low, due to inefficient use of local resources, such as crop residues, improper handling of manure and a lack of knowledge of organic farming.
Under these extreme conditions the use of synthetic inputs such as fertilizers and pesticides is risky and uneconomic and the use of these chemicals is limited to pockets of irrigated areas. In view of the high cost of chemical fertilizers and uncertain yields in this climate, several researchers have suggested increasing the use of manure arguing that providing balanced nutrition to plants through organic sources could be the most feasible option for mitigating the effect of climatic uncertainty.
Organic agriculture: socially and ecologically suitable for low rainfall areas
These low and erratic rainfall areas of northwest India are also characterized by extreme temperatures and light soils. The traditional farming systems are based on recycling crop residues to increase the humus content of these light soils. There are several other advantages of using and promoting this system in low rainfall areas.
- Diversified farming system: farming systems in the region are highly diversified, with annual and perennial crops, trees, farm animals and grasses. This system is efficient in nutrient recycling and in restoring soil fertility. In these areas 10-30 trees/ha are common and 2-5 animals are reared per family. This integrated organic (by default) farming system minimizes pest incidence and controls desertification.
- Efficient use of limited water: water is the scarcest resource in these regions. The use of synthetic fertilizers both increases water demand by crops and reduces the water-holding capacity of these light soils. In contrast to intensive farming with chemicals, it has been found by experiment and experience that the use of manure increases the soil’s water-holding capacity. Water use can further be reduced by growing low water-demanding crops such as spices and certain medicinal plants. This way precious water can be saved without decreasing farmers’ income.
- Low fertilizer use and quick conversion: in rain fed areas, due to the erratic pattern of rainfall, the rate of fertilizer application is very low (36.4kg/ha as compared to the national average of 76.8 kg/ha). This low fertilizer use can be a good opportunity for quickly and easily converting to certified organic farming. The National Organic Farming Policy identifies about 90% of low rainfall areas as high priority areas. This facilitates getting government subsidies for conversion to organic production in these regions.
- Rich traditional know-how: the rich traditional know-how in these areas provides further strong arguments for organic conversion as a way of ensuring the restoration of soil fertility and controlling pests.
- Availability of natural inputs: plants such as Azadirchata indica (neem) and Calotropis procera (Indian name: Aak) are good sources of bio-pesticides and are abundantly available in these areas. Minerals such as rock phosphate, gypsum and lime are available in large quantities. These soil improvers also provide plant nutrients and regulate the pH of the soils. In addition, the farming system includes farm animals, which provide waste products and are a good source of a balanced supply of plant nutrients.
- Employment opportunities: the high population density and its rapid growth remain underutilized throughout the year due to the erratic rainfall and limited irrigation facilities. The migration of human resources during drought periods inhibits the development of these areas. Since organic farming is more labour intensive and inputs are from local resources, it provides more employment opportunities.
- Soil improvement: the soils have a poor water-holding capacity and are low in most essential nutrients. The addition of organic matter not only improves the water-holding capacity but also enables the soil to supply nutrients in a balanced manner.
These factors all suggest that there are good opportunities to promote organic farming in India’s arid zones. To this end CAZRI has been carrying out on-farm research to improve the productivity of existing farming systems, making use of modern agricultural and ecological technologies and knowhow.
There are good opportunities to promote organic farming in India’s arid zones. To this end CAZRI has been carrying out on-farm research to improve the productivity of existing farming systems, making use of modern agricultural and ecological technologies and knowhow.
The availability of organic inputs in low rainfall areas
There is limited availability of organic inputs, such as crop residues and animal manure in low rainfall areas as biomass production is generally low. To learn more about how to enhance the quantity and quality of these inputs, a survey was done in four districts (Jodhpur, Nagaur, Pali and Barmer) during 2006-2008. A questionnaire was developed to get primary information from selected blocks. Secondary data was collected to get information at village and district level.
The survey generated the following insights:
The availability of these resources at farm level is influenced by several factors:
- cropping pattern,
- size of holding
- the availability of labour.
In general most farmers use pure cow dung, usually left out in open sunlight for months, causing huge nutrient losses, especially of nitrogen. On average 1.5-4.5 metric tonnes/ha of organic material is available at the farm in the form of crop residues and animal dung.
- Availability increases at village level by 1.5 to 2 fold when farmers keep dairy cows.
- There are also relatively large numbers of unproductive and old animals in villages, which provide manure in substantial quantities.
- Cattle urine provides 4.6 to 11kg/ha/yr of nitrogen (total arable land/total number of animals per village).
- Trees are an integral part of the farming system and contribute the equivalent of an average 40kg manure/tree/yr.
- Trees standing on common lands, protected areas and wastelands can also contribute to organic material.
Resource availability is further increased where there is intensive dairy farming (mostly in semi-urban areas). When added together all the organic inputs from available sources provide between 4.5 to 5 metric tonnes/ha. This is sufficient for sustainable rain-fed farming in these areas.
- Adopting other organic management practices can further increase the availability of nutrients. These practices should include:
- Crop rotation with leguminous crops such as cluster bean, moth bean and mung bean.
- Collecting dung, keeping it out of the sun prior to composting and improving composting methods. In hot arid zones pit composting under the shade of trees has been found to be most suitable.
- Tree leaf litter, animal urine, the bones of dead animals, non palatable weed biomass are some other rich and underutilized nutrient sources that should be utilized.
Together these organic inputs are available in sufficient quantities in low rainfall areas.
The ‘Like and Follow Organic System’ at CAZRI –The hub of capacity building
About the author: Arun K Sharma is a Senior Scientist at the Central Arid Zone Research Institute CAZRI and has been working on eco-friendly farming systems for low rainfall areas since 1992. E mail: email@example.com / firstname.lastname@example.org .