Effect of fertilizer and pre-monsoon crops on productivity of rice (Oryza sativa)-cropping based systems

A field experiment involving wheat (Triticum aestivum L. emend. Fiori & Paol.)-mungbean (Phaseolus radiatus L.) and maize (Zea mays L.)-rice (Oryza sativa L.) sequences (with varying mungbean residue management and fertilizer doses as treatments) was conducted under irrigated conditions at Bangladesh Agricultural Research Institute, Joydebpur, Gazipur, during 1996-99. Seed yield of mungbean was very low (0.25-0.61 tonne/ha) due to heavy pre-monosoon rainfall at maturity but considerable amount of green biomass (2.57-9.08 tonnes/ha) was obtained. Maize yield of 1.93-3.25 tonnes/ha was also affected by rainfall. Rice yield was 3.83-4.62 tonnes/ha, whereas wheat yield of 1.98-4.08 tonnes/ha in different treatments. All the 4 crops responded to fertilizer, with greatest response in wheat and maize. Mungbean (stubble removed or retained) in cropping system did not show any marked difference in total system productivity in terms of mean rice-equivalent yield for 3 years, but the system productivity was increased by increasing fertilizer dose. The mean rice-equivalent yield was greater by 12-13% for soil-test based fertilizer treatments than farmers' fertilizer treatments. Mean rice-equivalent yield involving maize was higher than that involving mungbean. But higher benefit : cost ratio was obtained from wheat-mung-bean (removed)-rice followed wheat-mungbean-rice with farmers fertilizer dose.