Effect of Iron, Zinc and Microbial Inoculants on Soil Health and Nutrient Uptake of Urdbean (Vigna mungo L.) in Vertisols

An experiment was conducted on urdbean during kharif 2021 at Instructional Farm, College of Agriculture, Ummedganj, Kota (Rajasthan). The experiment comprised 10 treatments viz. (Control, 75 % RDF, 100 % RDF, 75 % RDF + Rhizobium @ 600 g ha-1 seed inoculation, 75 % RDF + Bacillus megaterium @ 600 g ha-1 seed inoculation, 75 % RDF + Rhizobium @ 600 g ha-1 + Bacillus megaterium @ 600 g ha-1, 75 % RDF + 0.1 % FeSO4 + 0.5 % ZnSO4 at pre flowering and pod formation stage, 75 % RDF + 0.1 % FeSO4 + 0.5 % ZnSO4 at pre flowering and pod formation stage + Rhizobium @ 600 g ha-1, 75 % RDF + 0.1 % FeSO4 + 0.5 % ZnSO4 at pre flowering and pod formation stage + Bacillus megaterium @ 600 g ha-1, 75% RDF + 0.1 % FeSO4 + 0.5 % ZnSO4 at pre flowering and pod formation stage + Rhizobium 600 g ha-1+ Bacillus megaterium @ 600 g ha-1) was carried out in randomized block design with three replications. Significantly higher nitrogen (3.87 and 1.84 %), phosphorus (0.34 and 0.154 %), potassium (0.56 and 1.82 %), Fe (45.15 and 73.89 mg kg-1) and Zn (32.61 and 19.69 mg kg-1) content in seed and straw of urdbean were recorded with application of 75% RDF + 0.1 % FeSO4 + 0.5 % ZnSO4 foliar spray at pre flowering and pod formation stage + Rhizobium 600 g ha-1 + Bacillus megaterium @ 600 g ha-1 seed inoculation over rest of treatments. The significantly higher uptake of nitrogen (49.36, 27.84 and 77.20 kg ha-1), phosphorus (4.32, 2.33 and 6.65 kg ha-1), potassium (7.16, 27.44 and 34.60 kg ha-1), Fe (573.25 ,1120.36 and 1693.60 g ha-1) and Zn (413.78, 297.40 and 711.18 g ha-1) by seed, straw and total by urdbean crop with application of 75% RDF + 0.1 % FeSO4 + 0.5 % ZnSO4 foliar spray at pre flowering and pod formation stage + Rhizobium 600 g ha-1 + Bacillus megaterium @ 600 g ha-1 seed inoculation over rest of treatments. Application of Fe, Zn foliar spray and bio fertilizers seed inoculation did not significantly influence soil physico-chemicals properties during the experimentation. The maximum available nitrogen (285.21 kg ha-1), phosphorus (25.41 kg ha-1), potassium (252.66 kg ha-1), Fe (5.75 mg kg-1) and Zn (0.76 mg kg-1) after urdbean crop harvest in soil were recorded with application of 75% RDF + 0.1 % FeSO4 + 0.5 % ZnSO4 foliar spray at pre flowering and pod formation stage + Rhizobium 600 g ha-1 + Bacillus megaterium @ 600 g ha-1 seed inoculation over rest of treatments.