Multiple pathways of legume-based systems towards environmental, social, and economic sustainability in smallholder systems

Legume-based cropping systems (LCS) are considered instrumental to sustainable intensification in smallholder systems with multiple ecological, social, and economic benefits. Legumes are promising components in cereal-based cropping systems and can generate beneficial impacts on soil, animal., and human health. Such multifunctionality asks for contextualizing legumes and LCS from a system perspective involving several nexuses of soil, plant, feed, food, environment, market, nutrition, and health. System yield increment due to incorporation of legume has been observed in many sequential cropping systems. Legumes improve soil quality through biological nitrogen fixation and reduce chemical nitrogen (N) fertilizer application in the current and succeeding crops. It has been estimated that legume crops can fulfil 80%–90% of their N requirements during one crop season from this biological nitrogen fixation and transfer 0%–70% of this biologically fixed N to the succeeding crops. Legumes also utilize residual soil moisture of postrice fallow, require significantly less input, enhance the resilience of farming systems, promises a higher economic return, and ensure food and nutritional security of resource-poor farm families. Besides, legumes can reduce energy input requirements and mitigate greenhouse gases emissions from the cropping system. Legumes are essential components of livestock feed and can potentially improve the quantity and quality of livestock products. The LCS can also play a pivotal role in improving human health and nutrition, thus reducing malnutrition and morbidity. Profitable legume-based systems are being reported or designed, and value-added legumes are increasingly gaining popularity and share in the global food market. Summarily, legumes can be considered an important crop for ecological balance, poverty alleviation, and human nutrition. It is high time that we value and judge legumes in terms of their multifunctionality in the agricultural and food systems. We hypothesize that inviting a system perspective in understanding multiple pathways of legume-based systems might help us design and target LCS for smallholder systems.