Management for sustainable agriculture
With the current foodgrain production standing at abut 200 million tonnes, India needs to produce an additional 5-6 million tonnes of foodgrains annually in the next decade to meet the requirement of an estimated population of nearly 1120 million in 2010 AD. This high population also necessitates significant increase in the production of other agricultural products like oilseeds, cotton, animal products, fruits, vegetables etc. The added problem is that, now we will have to produce more food and other agricultural commodities under conditions of diminishing per capita arable land and irrigation water resources and expanding biotic and abiotic stresses.
Commercialisation of agriculture in response to domestic and world market changes will induce drastic shifts in cropping patterns and resource use. Nearly all agricultural production of the future must come from productivity of the soil, which is now mostly sick and substandard.
Sustainability is defined as "the successful management of resources to satisfy changing human needs while maintaining or enhancing the quality resources". It is measured as the ratio of output to input taking into account stock depletion.
Land, water, climate, flora and fauna are the basic natural resources for agricultural development, which are subject to various kinds of deteriorating influences. Production of more food require new agricultural technologies and management system and providing increased productivity per unit of plant, water, energy, labour and investment by suitable location, specific crop production technology, tillage operations, seeding, weed control, water and fertilizers application and crop management. Because of continuous cultivation over centuries and intensification of agriculture in recent years, there has been progressive and substantial depletion of the soil reserves. Of late, secondary and micronutrient deficiencies are also emerging and the crop response to these nutrients is increasing. The factors responsible for higher yield are high soil productivity, supply of balance crop nutrients are the most important. Soil productivity is based on the mineral composition and structure of the soil, depth and drainage facilities, organic matter, intensity of earthworm and microbial activities. Fairly well productive soil in combination with assured irrigation and optimum supply of nutrients can enhance the crop yields by 200-300%. Despite increasing use of chemical fertilizers over the years, there has been continuos nutrient mining of the soils. The nutrient remove from the soil for production of foodgrains and other agricultural crops far exceeds the nutrient applied. The threat to long term sustainability of agricultural is not due to alleged excessing use but primarily due to under use of fertilizer and the resultant nutrient mining of the soils. This is necessary for maintaining soil and ensuring sustainable agriculture.
Soil productivity can be enhanced through following practices:
Nutrient supplying power of soils, crop responses to added nutrient and amendment needs can safely be assets through soil testing choosing of right targets and application for appropriate amounts of nutrient, help to sustained soil fertility and crop yields.
To avoid loss of productive soil, agronomical and mechanical measures namely contour bunding, strip cropping, establishment of live hedges, mulching etc. should be followed.
To maintain or to improved soil fertility physical and chemical properties of soil and increased water holding capacity of soil use of organic manures viz. FYM compost, vermi compost, rural agricultural waste, tank silt application will help to built the soil organic matter base as a reliable index of fertility. Earthworms occuring in the soil are an indicator of the agro eco-systems health for stable aggregation of clay organic matter complexes and efficient nutrient recycling.
constraints affecting productivity and cultivation practices e.g. hard pans can be
corrected by breaking (deep tillage), compaction for excessively permeable soils,
preventing crust formation by organic mulching. Improvemental
Improvemental problematic soils
For favorable crop production salt affected soils can be improved by adding soil amendments viz. Acidic soils- Liming, Alkaline soils- Gypsum, sulphur, pyrites and adding soil conditioners e.g. crop residues, manures and other organic substances.
Application of major nutrients through chemical fertilizers has a direct influence on crop yields, also crops shows secondary and micro nutrient deficiencies and crop response to these nutrients hence attention has to be paid to increasing use of these nutrients which have appeared as major limiting factor.