EFFECT OF FERTILIZER AND PLANT-DENSITY MANAGEMENT ON PRODUCTIVITY AND ECONOMICS OF MAIZE (ZEA-MAYS) PLUS BLACKGRAM (PHASEOLUS-MUNGO) INTERCROPPING

A field experiment was conducted during rainy season of 1988 and 1989 on sandy-loam soil to study the effect of fertilizer and plant population of blackgram on productivity of maize (Zea,lays L.) + blackgram (Phaseolus mungo L.) intercropping. Separate fertilization (fertilizer for component crops applied separately to respective rows) gave 8.4% higher grain yield of maize than uniform fertilization (fertilizer for component crops mixed together and applied uniformly in rows irrespective of crops). Reduction in population of blackgram as an intercrop below 100% decreased the productivity of the system. Grain yield of intercropped maize was almost similar (4.O4-4.18 tonnes/ha) to its sole crop (4.32 tonnes/ha) when grown with 100% population (20 kg seed/ha) and 50 (10 kg N and 8.8 kg P/ha) to 100% (20 kg N and 17.6 kg P/ha) fertilizer to blackgram and component crops fertilized separately. This combination also gave higher grain yield (0.82-0.84 tonnes/ha) of the intercrop blackgram, suggesting that 50% fertilizer to blackgram could be saved without any significant reduction in production potential of the system. Maize + blackgram intercropping system with 100% population and 50% fertilizer to blackgram and fertilized separately to both the component crops gave maize-equivalent yield of 5.88 tonnes/ha and net return of Rs 10 470/ha.