(introduction...)

R.N. Prasad (1997) stated:

“The ultimate goals or the ends of sustainable agriculture are to develop farming systems that are productive and profitable, conserve the natural resource base, protect the environment and enhance health and safety in the long run. Traditional agricultural systems that met the test of sustainability in the past have not been able to respond adequately to today's growth in demand for agricultural commodities required by the current population pressures of humankind and animals and rapidly declining resources of good quality arable land and water resources.

The basic principles of soil management for sustainable agricultural systems are:

· Replenish nutrients removed
· Maintain the physical condition
· No build-up of weeds, pests and diseases
· No increase in soil acidity or toxic elements
· Soil erosion must be controlled to be equal or less than the rate of soil genesis”.