Growth, symbiotic traits, productivity and nutrient uptake as influenced by dose and time of nitrogen application and Rhizobium inoculation in mungbean [Vigna radiata (L.) Wilczek

Abstract

A field experiment was conducted to study the response of mungbean to dose and time of nitrogen (N) application and Rhizobium inoculation. Application of 12.5 kg N ha−1 + Rhizobium inoculation recorded the plant height, plant dry weight, root length, root dry weight, number of pods plant−1, 100-seed weight, biological yield and grain yield either significantly higher or statistically on par with N application at 12.5, 25, 50, 100, 50 + 50 kg ha−1 and Rhizobium inoculation alone. Nodulation, in general, decreased with increase in N dose, and was found to be significantly higher with application of 12.5 kg N ha−1 + Rhizobium inoculation than under different doses of N application. Although application of 50 kg N ha−1 produced the highest number of pods plant−1 and 100-seed weight, resulting in the highest grain yield but it was on par with 50 kg N ha−1 + Rhizobium inoculation and other nitrogen levels. Application of 50 kg N ha−1 recorded the highest N content in grain and its uptake by grains whereas the highest N content in straw and its uptake by straw as well as by the crop was recorded in treatment receiving 100 kg N ha−1. It can be concluded that application of N beyond 12.5 kg ha−1 is not beneficial in mungbean in terms of grain yield and environment point of view and integrated use of 12.5 kg N ha−1 along with Rhizobium inoculation is the most efficient in terms of high nodulation and grain yield.