Synergistic Effect of Nitrogen-Fixing Bacteria and Nitrogen Levels on Mung bean (Vigna radiata L.) Growth and Yield

Abstract

Abstract Mung bean holds significance as a vital leguminous crop, cultivated for its nutritional value and economic importance. This research delved into the impacts of nitrogen-fixing bacteria and varying nitrogen levels on the growth and yield of mung bean. The study was conducted at the Cereal Crop Research Institute (CCRI) in Pirsabak, Nowshera, employing RCB design comprising three repeats. Several agronomic and soil parameters were studied. The first factor was nitrogen fixing bacteria having control, Azotobactor, Azospirillum and Rhizobium and the second factor was nitrogen levels having N1 i.e. control (0 kg ha− 1), N2 (30 kg ha− 1) N3 (60 kg ha− 1), and N4 (90 kg ha− 1). The results revealed that emergence m− 2 of mung bean were not significantly affected by either nitrogen fixing bacteria or nitrogen levels. However, all the other parameters were significantly affected by both nitrogen fixing bacteria and nitrogen levels. Yield attributes, including branches plant− 1, plant height, pods plant− 1, seeds pod− 1, nodules plant− 1, thousand seed weight and seed protein were the highest when crop was treated with Rhizobium as compared to other inoculants. Similarly, the highest seed yield was obtained from Rhizobium treatment (842 kg ha− 1) whereas control produced (715 kg ha− 1). Biological yield was also highest with Rhizobium treatment (4277 kg ha− 1) and lowest was recorded for the control (3790 kg ha− 1). As for nitrogen levels, most of the yield attributes improved and recorded statistically similar values when N3 and N4 were administered. For instance, N4 and N3 produced (867 and 846 kg ha− 1, respectively) seed yield that produced significantly higher seed yield than the control (677 kg ha− 1). Similar to this, biological yield was also higher at N4 and N3 producing (4251 and 4236 kg ha− 1, respectively), while plots having no nitrogen recorded lowest biological yield (3740 kg ha− 1). Moreover, soil analysis revealed that soil total nitrogen improved substantially with increasing N dose, while slight changes in soil pH was seen. Hence, it can be inferred that the utilization of Rhizobium in conjunction with a nitrogen application at a rate of (60 kg ha− 1) can potentially enhance growth and yield of the mung bean.