Performance, radiation capture and use by maize–mungbean–common bean sequential intercropping under different leaf removal and row orientation schemes

Abstract

AbstractFood security under smallholder farming can be improved through innovative intensification of cropping systems. Maize (Zea mays L.) – mungbean (Vigna radiata (L.) Wilczek) – common bean (Phaseolus vulgaris L.) sequential intercropping was studied to evaluate the patterns of radiation capture and radiation use efficiency and to determine the effects of leaf removal and row orientation on performance and intercropping efficiency. Sequential intercropping captured 1039 MJ m−2 photosynthetically active radiation (PAR) accounting for 70% of incident seasonal PAR. The corresponding sole stands for maize captured 41%, mungbean 29%, common bean 34% and mungbean–common bean 63%. Intercropped components had interception ratios of 0.98, 0.31 and 0.61 for maize, mungbean and common bean, respectively. Associated maize used intercepted light with similar efficiency, mungbean with greater efficiency and common bean with lesser efficiency compared to sole crops. Maize leaf removal and row orientation had no significant effect on performance and partial land equivalent ratio (LER) of maize. Leaf removal under East–West (EW) orientation increased grain yield by 96%, total biomass by 63%, partial LER by 92%, in common bean and total LER by 7%. Leaf removal also improved grain yield, biomass yield, partial LER, in common bean and total LER during the wetter year of 2013. Similarly, EW orientation was advantageous in 2013 raising total LER by 8%. Maize leaf removal and EW row orientation had synergistic effects on intercropping efficiency and economic benefit and both have exerted positive influence under favourable weather. Total LER values of 1.47 in 2013 and 1.29 in 2015 had revealed greater biological efficiency for intercropping during both years though it was more profitable in 2013. Thus, the cropping system can be adopted under timely onset of the rainy season using EW row orientation while leaf removal can also be practiced depending on weather conditions and convenience.