Vol. 11, Issue 8 (2022)

Author(s):
R Swetha, M Sree Rekha, K Chandrasekhar and K Jayalalitha

Abstract:
Water is considered as a key input for agriculture which is becoming scarce due to its requirement in agricultural, industrial and domestic sectors. To improve water use efficiency(WUE), precise strategies need to be formulated. Deficit irrigation (DI) is an optimization strategy in which irrigation is applied during drought-sensitive growth stages of a crop or application of water below crop-water requirements. A field experiment was conducted during rabi season 2021-22 to assess the performance of sorghum under different irrigation practices and nitrogen at Agricultural College Farm, Bapatla. The experiment was conducted in a split -plot design with three replications. The experiment consisted of twelve treatment combinations with 3 Irrigation practices viz., full irrigation(I₁), managed deficit irrigation (I₂) and deficit irrigation(I₃) as main plots and four nitrogen levels. viz., 100(N₁), 80(N₂), 60(N₃) and 40 (N₄) kg N ha^-1) in sub-plots. The results revealed that significantly higher plant height, drymatter accumulation and leaf area index(LAI)at harvest was recorded with full irrigation (I₁) compared to deficit irrigation. Full irrigation produced significantly higher of rabi sorghum compared to deficit irrigation but was on par with managed deficit irrigation. Among nitrogen levels, significantly higher grain and stover yield was recorded with 100 kg N ha^-1 compared to other levels. Among the irrigation practices significantly higher water use efficiency was recorded with deficit irrigation compared to I₁ and I₂. Application of 100 kg N ha^-1 recorded higher WUE compared to 40 and 60 kg N ha^-1 but was statistically comparable with 80 kg N ha^-1.