Bio-Diverse Farming System Models for Dryland Agriculture

Abstract

1. Introduction Unabated land degradation due to nutrient mining combined by topsoil loss by water erosion and climatic change towards adverse conditions are the serious problems affecting the dryland agriculture. In this connection, an early action is to be taken by controlling erosion, replenishing the soil with high biomass for revitalizing the various soil processes and creation of congenial microenvironment. Invariably this will improve the soil resillence, quality and mitigates the drought affect. The practice that is needed is the resource conservation and utilization based template created by using perennial, semi-perennial and annual plants. This knits the farmers to the land and generates employment much of the year. Use of cash returning species will improve the socio economic conditions of the farmers. A farming system model cutting across the production systems and agro eco sub regions is envisaged hereunder based on research data, and experience in the drought prone blocks. 1.1 Climate Change-A new challenge to the sustainability of dryland agriculture Climate change has become a great concern and attracted the attention of all nations in the world. The most important aspect is the increase in global average air temperature, which is primarily ascribed to the increased combustion of fossil fuels, and land use changes through intensive agriculture and urbanization. In India the warming period is observed in post monsoon and winter seasons with little variation during monsoon season. The projected change for India is that the increase in temperature is likely to be less in kharif than in rabi season. The rabi rainfall may exhibit large uncertainty whereas kharif rainfall is likely to increase by as much as 10 percent. Such global climate changes will affect agriculture considerably through its direct and indirect affect on crops, cropping systems, livestock, pests and diseases, weeds, etc., threatening the food security. Thus, dryland agriculture and its productivity totally rely on agro climate and its changes with time. Any change in the rainfall affects the performance and sustainability of cropping systems, soil resilience and water balance. In the absence of support of assured irrigation, the affects are more pronounced. A trend analysis of five yearly moving average annual rainfall in the last century and its variability provided the following picture for some of the All India Co-ordinated Research project for Dryland Agriculture centers: