Impact of varying irrigation levels on yield and quality of summer green gram (Vigna radiata L.) in south Gujarat condition

The field investigation was conducted at College Farm, Navsari Agricultural University, Navsari, to assess the impact of land configuration on summer green gram (Vigna radiata L.) under South Gujarat conditions during the summer seasons of 2022 and 2023. The experiment utilized a split plot design with 24 treatment combinations, comprising four irrigation levels: irrigation at 30 and 45 DAS (I1), irrigation at 30, 45, and 60 DAS (I2), irrigation at 30 and 60 DAS (I3), and irrigation at 45 and 60 DAS (I4) as main plots. Two bio compost treatments were included in sub plots: without bio compost (B0) and with bio compost at 5 t/ha (B1), replicated four times. The experimental soil was clayey, low in organic carbon and available nitrogen, medium in available P2O5, and high in available K2O, with a slightly alkaline pH and normal electrical conductivity. Results from both years indicated that the highest irrigation level (I2) significantly improved plant height at 60 DAS and harvest, increased the number of branches and root nodules per plant at 40 and 60 DAS, and enhanced dry matter accumulation and crop growth rate compared to I4. However, treatments I2 required more days to reach 50% flowering and maturity. Furthermore, I2 also resulted in a higher number of pods per plant, greater grain weight per plant, and increased grain and stover yields. In terms of nutritional content, I2 showed the maximum protein content, protein yield, and higher N, P, and K levels in the grain compared to I4. Notably, irrigation levels did not significantly affect initial or harvest plant population, pod length, 100-grain weight, grains per pod, harvest index, soil pH, electrical conductivity, organic carbon content, or nutrient status post-harvest. The highest field water use efficiency was observed with two irrigations (I1), as opposed to the three irrigations in I2. Overall, the highest consumptive water use and significant improvement in N, P, and K uptake were recorded under the I2 treatment.