Influence of rice varieties and fertility levels on performance of rice and soil nutrient status under aerobic conditions
Scarcity of water resources in India is limiting the production of flooded rice crop. A field experiment was conducted in factorial RBD with sixteen treatment combinations including four rice varieties viz. V1: PR-115, V2: DRRH-3, V3: PAC-837 and V3: PR-121 and four fertility levels viz. F1: control (N0P0K0), F2: N, P2O5, K2O at 90: 45: 22.5 kg ha-1, F3: N, P2O5, K2O at 120:60:30 kg ha-1 and F4: N, P2O5, K2O at 150: 75: 37.5 kg ha-1 replicated thrice. The results revealed that among the different varieties, PAC-837 recorded highest plant height and number of tillers m-2 at all the growth stages. All yield attributes viz. number of effective tillers m-2, number of seeds per panicle, 1000-grain weight, spikelet sterility and grain yield, straw yield and harvest index significantly differed in different varieties and were recorded highest in PAC-837 which were however, statistically at par with DRRH-3 except grain yield and effective tillers m-2. Rice variety PAC-837 recorded highest grain yield of 45.65 q ha-1 and straw yield of 59.98 q ha-1. Among the fertility levels, number of effective tillers m-2 significantly increased up to 120: 60: 30 N-P2O5-K2O kg ha-1 thereafter nonsignificant differences were noticed. The grain and straw yield increased up to 150: 75: 37.5 N-P2O5-K2O kg ha-1 and recoded grain yield of 52.78 q ha-1 and straw yield of 73.85 q ha-1 with application of 150:75:37.5 N-P2O5-K2O kg ha-1. Nutrient application of 150: 75: 37.5 N-P2O5-K2O kg ha-1 recorded highest available N (238.16 kg ha-1), P (16.18 kg ha-1) and K (163.25 kg ha-1) in soil after harvest of the crop. Higher available nitrogen (235.28 kg ha-1), phosphorus (16.38 kg ha-1) and potassium (154.24 kg ha-1) n soil were recorded with PR-121 and lowest available major nutrients were recorded with variety PAC-837. This study would help to introduction and adaptation of new rice variety PAC-837 with application of 150: 75: 37.5 N-P2O5-K2O kg ha-1 under aerobic conditions in Shiwalik foothills region of North-Western Himalayas.