Symbiotic nitrogen fixation, growth and yield response of common bean and cowpea for Rhizobia inoculation and micronutrients (B and Mo) application in mid-hill regions of Nepal

This is a CIFSIRF funded project.Challenges associated with legume production in Nepal include: lack of high yielding varieties and crop specific management (e.g., disease/pest management) practices, loss of soil fertility including micronutrients, poor access to agricultural inputs and services, shortage of irrigation water, lack of mechanization, and labour shortages which led to poor yields and low economic returns to farmers (Chapagain and Gurung, 2010; Chapagain and Raizada, 2017). Farmers mostly used untreated seeds from previous season harvest to cultivate these crops and very little attention has been given to study the effects of bacterial inoculation on the crop performance and soil health through systemic on-farm trials. Symbiotic nitrogen fixation of 3 legumes can be improved by introducing efficient rhizobia strains for N fixation (Thilakarathna and Raizada, 2017), and also through application of soil deficient micronutrients which are important for different stages of SNF (Weisany et al., 2013). This research explores the opportunities to use different rhizobia strains (native as well as exotic) along with micronutrients (Boron and Molybdenum) on two legume crops (e.g., cowpea and common bean) to enhance SNF, crop yields (grain and plant biomass), plant and grain N content, and offers the most productive combination(s) for each crop