The field experiment titled, “Effect of phosphorus, molybdenum, and Rhizobium on quality and nutrient uptake of greengram (Vigna radiata L.) in loamy sand” was conducted at the Agronomy Instructional Farm, Chimanbhai Patel College of Agriculture, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, during the kharif seasons of 2019 and 2020, across different but adjacent similar sites. The soil of the experimental field was loamy sand in texture, with a normal pH and electrical conductivity (EC). The field was low in available nitrogen, medium in available phosphorus and potassium, and deficient in available molybdenum. The experiment involved eighteen treatment combinations based on the following factors: Phosphorus: Three levels (P1: 20 kg P₂O₅ ha⁻¹, P2: 40 kg P₂O₅ ha⁻¹, and P3: 60 kg P₂O₅ ha⁻¹), Molybdenum: Three levels (Mo0: 0.0 kg Mo ha⁻¹, Mo1: 0.5 kg Mo ha⁻¹, and Mo2: 1.0 kg Mo ha⁻¹) and Rhizobium: Two levels (R0: Without Rhizobium inoculation and R1: With Rhizobium inoculation) These treatments were evaluated using the GM 4 cultivar of greengram in a randomized block design (R.B.D.) under a factorial concept, with three replications.
The concentration of P in seed and stover increased significantly with P₂O₅ application, along with a marked uptake of N, P, K, and Mo. Molybdenum application (0.5 kg Mo ha⁻¹) significantly enhanced N and Mo concentrations, protein content, and nutrient uptake in greengram seed and stover compared to the control. Seed inoculation with Rhizobium further improved N and Mo content and uptake. Interaction effects of P × Mo and P × Rhizobium showed significant increases in N, P, K, and Mo uptake. The combination of 40 kg P₂O₅ ha⁻¹, 0.5 kg Mo ha⁻¹, and Rhizobium inoculation was most beneficial for greengram (GM 4) in light-textured soils of north Gujarat.
