Intercropping for enhanced yield stability and food security

Current monoculture food production facing a lot of challenges. The adverse effect of climate change will shift the current agricultural production towards critical threshold level in many parts of the world. Increased global mean temperature, changes in rainfall pattern, pest and disease infestation and other localized extreme events significantly decreases the yield level and increases the yield variability year to year in current monocropping systems, throwing more than 1 billion people in food insecurity. Now-a-days intercropping have been considering as a viable alternatives for increasing the agricultural productivity and reducing the yield variability over the years. No quantitative synthesis have been made on intercropping yield stability. The aim of this study is to analyze the intercropping ability to enhance yield stability and ensure food security compare with monocropping systems. This study consists of two intertwined section: meta-analysis and field experiment. Meta-analysis on intercropping literature was conducted to quantify the yield stability of intercrops, focusing on the effect of intercrop components, experimental patterns, intercropping design and climatic zone. The three years field experiment was used to analyze the effect of three different nitrogen levels (0, 40 and 80 kg N ha−1) and five different cropping systems (IC1= 80:20; IC2=50:50; IC3= 20:80 of barley & pea respectively; barley sole crop; pea sole crop) on productivity, land use efficiency and yield stability. In meta-analysis only coefficient of variation (CV) but for field experiment CV and coefficient of regression have been used for assessing the yield stability. The meta-analysis results showed that cereal-legume intercropping systems significantly reduces the yield variability of their respective sole crops. Intercropping in replacement design have significantly lowest CV value. In tropical region cereal production shows higher yield variability than intercrop and legume sole crop. However, in tropical region intercropping reduces 49% yield variability of cereal sole crops, although higher yield stability was observed in sub-tropical region for all cropping systems. Moreover the analysis showed that a higher yield level provides higher yield stability in production systems. Results of the field experiment showed that N fertilizer has no strong effect on the intercrop yield. N fertilizer significantly increases barley grain and biomass yield but reduces the pea yield. Moreover N fertilizer significantly reduces LER values indicating that available soil N decreases the complementarity among the intercrop component crops and increases the interspecific competition. No significant difference was observed among the CV of cereal sole crop and intercrops except legume sole crop. The regression analysis showed that intercropping with higher pea proportion have higher yield stability in both grain and biomass yield. Finally all of the analysis showed that cereal-legume intercropping have a substantial impact on higher yield and yield stability and could improve the food security and livelihood. Overall following this agroecological practice in cropping systems could keep contribution to move the current agroecosystems one step towards sustainability.