Evaluation of legume intercropping in conservation of fertilizer nitrogen in maize culture

Experiments made over a period of 2 years (1975–6) covering three crop seasons at Pantnagar, India, on the comparative utility of intercropping the principal maize crop with legumes in economizing fertilizer N requirements of the former, indicated that among soya bean, cowpea, pigeonpea and groundnut, soya bean was the most suitable. At 40 kg N/ha intercropping maize with soya bean gave 19·5% more yield than taking it as a pure crop. When the option to use adequate fertilizer N does not exist, as is invariably the case with the average Indian farmer, intercropping maize with legumes, such as soya bean, is the logical way out. All the intercropping treatments left sufficient residual fertility to significantly increase yield of a wheat crop given no fertilizer which followed maize.