The over use of chemicals to intensify crop production poisons both people and animals besides polluting water and soil resources. Increasing dependence on water for irrigation depletes aquifiers and water courses, causing shortages for other users and increasing waterlogging and soil salinity.

Moreover, expansion of farming onto land unfit for cultivation is leading to erosion. Forests, with their rich diversify of flora and fauna are under threat. Overgrazing by livestock is leading to degradation of pastures. These are some of the environmental problems which threaten food production. The search continues for means to boost crop yields. But ways are needed to grow more food without depending on pesticides andchemical fertilisers. The prime mover of agricultural development in India has been new technology with options that allow farmers and other users of natural resources to produce more per unit area at lower cost.

Sources: The new technology enters the agriculture sector from two major sources.s The first source is farmers themselves, who, through their own innovations and experimentation on farms, have perfected tools such as the hoe and the plough, developed seeds and plants through preservation and selection, designed crop mixtures and rotations leading to improved productivity. Until late in the last century, farmers working on their traditional production systems were the major suppliers of new technologies.

Based on hundreds of years of their experience, these systems are often highly productive and sometimes more reliable than the so-called improved systems based on mono cropping and the use of chemical inputs. There is a great deal to learn from them. Yet in today's world of shrinkingnatural resources and rapidly rising populations, traditional production systems are increasingly unable to meet the food and income needs of the growing urbanized consumers. In short, farmers' efforts alone are no longer enough.

The second major source of new agricultural technology is science. Through technology is science. Through resource, scientists increase their understanding of the physiological mechanisms that condition plant and animal growth and of the genetic basis for desirable traits in crops and livestock. This knowledge and the technology options that developed from more detailed understanding are indispensable tools in the struggle for good security and poverty alleviation.

But while agricultural science was becoming overspecialised and agricultural extension was becoming too concerned with delivering simple bits of technology, realisation began to dawn that everything is interconnected in an ecosystem. Addressing single crops and disciplines may increase productivity in the short termbut also result in diminishing the capability of the ecosystem in the long run. The Farming Systems Approach to research and extension recognizes the complexity and interdependence of resource subsystems and the central role of participation of farm households and communities in research and development.

Indigenous knowledge: In the field of sustainable development there are valuable lessons to be learnt from the indigenous knowledge of local communities. Traditional agricultural practices stress reverse for nature as the very source of life. The five principal elements - prithvi (earth), jal (water), pawak (fire), vayu (air), akasa (space) - venerated as life-giving and life-nurturing have been treasured,s conserved and harnessed for sustainable use and reuse. Not only in India but indigenous cultures in several parts of the world view land not as a commodity to be bought and sold sin impersonal markets but as a substance endowed with sacred meaning embedded insocial relations and fundamental to the understanding of the community's existence and identity.

The inter-generation wisdom ensured that livelihood operations sin land and water use, nutrient management, crop protection, storage, preservation and food processing were performed in the most eco-friendly manner.

There has been a great resurgence of interest in recent times in studying traditional methods of agriculture. The interest has been world-wide and has encompassed diverse areas of plant science such as agronomical methods, soil testing and classification, pest control and crop protection techniques, irrigation, climatology and forestry. These studies have become important in the light of world-wide efforts to seek alternatives to modern techniques and evolve sustainable eco-friendly strategies for agricultural development.

The importance of indigenous technology and practices to sustainability, is being brought centre-stage through pooling of traditional knowledge, distilling and evaluating in thecontext of modern scientific and technological environment and harnessing it for sustainable agricultural growth. It is being recognized that new technologies and practices would be of greater use and more readily acceptable to farming communities ifthey are well ingrained in the indigenous systems. The Farming Systems Approach now being adopted for both research and extension in corporates farmers' circumstances and preferences into technology generation and dissemination.