Evaluation of organic manures for sustaining productivity in groundnut-rice cropping system

Groundnut–rice is a very popular cropping sequence adopted by the farmers in Konkan region due to favorable climatic conditions. The nutrient management plays a dominant role in increasing the productivity as well as maintaining the soil health. The study was conducted to evaluate the effect of different organic manures in groundnut-rice cropping system. Field experiments were conducted at Agronomy Farm, College of Agriculture, Dapoli during 2006–2009. Continuous application of organic manures over a period of three years in groundnut-rice cropping system did not show any improvement in the available nutrients. On the contrary it resulted in the net negative balance of available N from 22.8 kg (lowest due to poultry manure) to 91.8 kg N/ha (highest in unfertilized plot) over initial soil fertility. In general all the organic manures resulted in negative balance of available potassium in groundnut-rice cropping system.