AGRONOMIC MANAGEMENT STRATEGIES FOR IMPROVING CROP ESTABLISHMENT, PHYSIOLOGY AND PRODUCTIVITY OF GRAIN LEGUMES: A REVIEW

Abstract

Grain legumes including green gram, black gram, chickpea, lentil, field pea, cowpea, pigeonpea, common bean and soybean are central to protein and nutritional security, cropping-system diversification and biological nitrogen fixation in Indian agriculture, yet their realized productivity remains well below attainable potential. This review synthesizes recent literature on two of the most consistently reported agronomic determinants of productivity time of planting and crop geometry and their downstream effects on crop establishment, physiological performance, resource use efficiency and yield across major grain legumes. Evidence indicates that timely sowing consistently improves germination, nodulation and canopy development, while delayed sowing depresses growth and yield through moisture and thermal stress during critical growth stages. Crop geometry studies show a broadly conserved density–competition trade-off, in which closer spacing raises biomass per unit area but reduces per plant yield attributes, while wider spacing has the opposite effect; the position of the optimum shifts with species and growth habit. Climate-smart practices, conservation agriculture, and emerging tools such as crop simulation models, phenotyping and remote sensing are reviewed for their potential to translate these findings into site specific management recommendations. Key research gaps include the scarcity of multi-legume, multi-location trials that test sowing time and geometry simultaneously, limited canopy-architecture models incorporating growth habit, and insufficient farm-level economic validation of precision-agriculture tools. Realizing the productivity potential of grain legumes will require multi-environment agronomic trials integrated with climate smart and precision-agriculture frameworks, translated into practical, region-specific recommendations for growers and extension agencies.