Vol. 11, Issue 10 (2022)

Author(s):
K Sridhar, A Srinivas, K Avil Kumar, T Ram Prakash and P Raghuveer Rao

Abstract:
A field experiment was conducted on clay loam soil at Agricultural Research Institute, Rajendranagar, Hyderabad, Telangana during rabi seasons of 2016-17 and 2017-18 to identify optimum scheduling of alternate wetting and drying irrigation under different nitrogen levels on rice varieties. The treatments consisted of three irrigation regimes (recommended submergence of 2 to 5 cm water level, AWD irrigation when water level falls below 3cm from soil surface in perforated pipe, AWD irrigation when water level falls below 5cm from soil surface in perforated pipe) as main plot treatments, three nitrogen levels (120, 160 and 200 kg N ha^-1) as sub plot treatments and two rice varieties (‘KNM-118’ and ‘JGL-18047’) as sub-sub plot treatments laid out in split-split plot design with three replications. Protein content in the grain was not significantly influenced by irrigation regimes. Application of 200 kg N ha^-1 (N₃) recorded significantly higher grain protein content which was on par with application of 160 kg N ha^-1 (N₂). Significantly higher head rice recovery of rice was recorded with recommended submergence of 2 to 5 cm water level as per crop growth stage (I₁) over other irrigation regimes. Nitrogen levels did not influence the head rice recovery of rice. Recommended submergence of 2 to 5 cm water level as per crop growth stage (I₁) recorded significantly higher N uptake at panicle initiation and flowering stages which was at par with AWD irrigation of 5 cm when water level falls below 3 cm from soil surface in perforated pipe (I₂). The grain and straw uptake of N, P and K was higher with recommended submergence of 2 to 5 cm water level as per crop growth stage (I₁) and AWD irrigation of 5 cm when water level falls below 3 cm from soil surface in perforated pipe (I₂). Significantly higher grain and straw uptake of N, P and K was recorded with application of 200 kg N ha^-1 (N₃). The post harvest soil status viz., pH, EC, organic carbon, bulk density and available soil nitrogen, phosphorus and potassium was not significantly influenced by irrigation regimes, nitrogen levels and varieties.