Organic sources as substitute of fertilizers under intensive cropping

In northern part of India maize-wheat is prominent cropping systems covering around 8.0 and 27.7 mha area under cultivation, respectively. Due to decline in soil organic matter, over mining of nutrient reserve and non-availability of cost effective fertilizer, productivity of this cropping system is declining. Among the various factors for improving productivity, nutrients particularly nitrogen plays a vital role. Fertilizers and biosources are the major sources of nitrogen supply for crops. But experiments revealed that continuous use of chemical fertilizers in an indiscriminate manner leads to deleterious effect on soil fertility and yield sustainability. This calls for a search on alternative sources of nutrients, which can at least partially substitute the fertilizer nitrogen for cereal-cereal system. Since, fertilizer is not a complete substitute for organic matter and vice-versa and their role is complementary to each other. Incorporation of farm waste as straw as well as practice of green manuring is viable options. Hence, an inquiry was made to explore the possibilities of substitution of fertilizer nitrogen through organic sources under maize-wheat sequence.