ECONOMIC FEASIBILITY OF INTEGRATED NUTRIENT MANAGEMENT FOR SUSTAINABLE RAINFED MAIZE- LEGUME BASED INTERCROPPING SYSTEMS

Abstract

Bio-economic efficiency of maize - legumes based intercropping systems under different fertility treatments and its effects on subsequent wheat crop were evaluated at National Agriculture Research Center (NARC) Islamabad Pakistan. Cropping systems were kept in vertical blocks and fertility treatments in horizontal blocks replicated thrice with RCBD split block set up. Five cropping systems viz. maize alone, sole mungbean, maize + mungbean intercropping, sole mashbean and maize + mashbean intercropping and five fertility treatments ( control ; inoculation ( maize seed with plant growth promoting rhizobacteria (PGPR) and legumes seed with rhizobium strain (TAL 169) + PK (80-60 kg ha -1 ), (120-80-60 NPK kg ha -1 ); poultry manure at the rate of 15 t ha -1 , and half poultry manure (7.5 t ha -1 ) + half PK (40-30 kg ha -1 ) + inoculation with PGPR for maize and TAL 169 for legumes) were included in research trials. The objectives this study were to evaluate efficiency of maize crop in pure stand and test its compatibility under different legume intercropping systems; to compare the potential of legumes in maize-based systems under biological, chemical and organic fertility protocols for sustainable farming systems and its impact on succeeding wheat crop. Results of the study revealed that poultry manure @ 7.5 t ha -1 + 40 kg ha - 1 Phosphorus and 30 kg ha -1 Potassium) + plant growth promoting rhizobacteria improved maize yield by 38 % while PK (80:60 kg ha -1 ) + Rhizobium inoculation enhanced the yield of mungbean and mashbean by 32 % and 28 % over control, respectively. Intercropping reduced the yields of mungbean and mashbean by 28 % and 23 %, respectively, but maize + mashbean and maize + mungbean did not affect maize yield compared to respective sole cropping systems. Land use efficiency was enhanced 76 % under maize + mashbean and 70 % under maize + mungbean intercropping systems. Land occupancy duration i.e. area time equivalent ratio (ATER) 44 % was higher under maize + mashbean and 40 % under maize + mungbean intercropping systems. In same way, maize + mashbean intercropping 12 posted 18 % higher hectare days i.e. area harvest equivalent ratio (AHER) compared to maize + mungbean intercropping systems (14 % hectare day). Likewise, higher values for aggressivity (A), relative crowding coefficient (RCC), actual yield loss (AYL), competitive ratio (CR), monetary advantage index (MAI) intercropping advantage (IA), resource use efficiency (RUE), agronomic efficiency (AE) and maize equivalent yield (MEY) were recorded in maize + mashbean than maize + mungbean intercropping systems. Higher CGR, NAR values were recorded of maize with half PM + half PK + inoculation. Wheat grain yield improved by 12 % and 11 % sown after mashbean and mungbean treated with PK (80:60 kg ha -1 ) + Rhizobium inoculation respectively. In similar fashion, wheat grain yield increased by 20 % after 15 t ha -1 poultry manure and 15 % wheat grain yield was improved with poultry manure @ 7.5 t ha -1 + PK (40:30 kg ha -1 ) + inoculation. In maize higher crop growth rate (CGR) and net assimilation rate (NAR) were registered in poultry manure plots 7.5 t ha -1 + PK (40:30 kg ha -1 ) + inoculation treatment. Same variables increased the pH, NPK and organic matter in soil. Maize + mashbean with NPK (120:80:60 kg ha -1 ) gave the highest net benefit of Rs. 68720.75 ha -1 without wheat in succession and Rs. 96543.95 ha -1 with wheat in succession, respectively. According to partial budget analysis highest net benefit of Rs.148069.92 ha -1 was accrued in maize + mashbean – wheat sequence with half poultry manure + half PK + inoculation.