Effect of different fertilizer levels on root nodulation and fodder quality in Rice bean (Vigna umbellata) genotypes

Abstract

Studies were conducted to determine the effect of different levels of N, P and K on nodulation and quality traits of fodder in rice bean genotypes. The treatments consisting of NPK levels viz; 0:0:0 (T0) control or 10:30:10 (T1) and 20:60:20 (T2) kg/ha exhibited significant differences amongst the genotypes in nodulation. Genotypic response of rice bean (Vigna umbellata (Thunb) Ohwi and Ohashi) to Rhizobium spp. was studied in terms of nodule number and fresh weight (g) under different fertilizer treatments. Genotype IC-140796 was observed to have significantly high number of nodules and fresh weight (g), whereas, IC-137200 and JCR-107 had significantly lower number of nodules in comparison to the check (BRS-2). Fertilizer treatments significantly affected nodule number and weight. Crude fibre and total ash increased significantly in the fodder samples with increasing rates of N, P and K, whereas, crude protein content showed non-significant effects. Number and nodule weight showed significant positive of correlation between T1 and control, whereas plant biomass and days to flowering showed significant positive between association T2. Plant biomass showed positive correlation with crude fibre in T2, whereas, crude protein and ash content had positive correlation in T1 and T2. Ash and nodule number showed positive association in control only. Among the three treatments under study, T2 treatment with NPK ratio @ 20: 60:20 Kg ha –1 was observed promising for nodulation and quality traits.