THE EFFECT OF NITROGEN RATE ON RICE TILLERING AND GRAIN YIELD UNDER WATER SAVING IRRIGATION

In order to study the best nitrogen regime under water saving irrigation condition, an experiment was conducted based on completely randomized block design with 3 replications on rice at Caofeidian, north of China in 2018. There were six treatments, that was five levels of nitrogen (CK0 = 0, T1 = 217.8, T2 = 254.1, T3 = 290.4 and CK1=363 kg ha(-1) i.e. farmers' traditional practice) under water saving condition of optimize alternate wetting and drying irrigation (OAWD) water 10,800 m(3) ha(-1), compared with farmers' practice nitrogen level of 363 kg ha(-1) under farmers' traditional irrigation practice water13,800 m(3) ha(-1) (CK2) as check. The results clearly indicated that excess nitrogen and water influenced negatively the productive tillers. Whereas proper nitrogen rate under OAWD irrigation enhanced the grains number of per panicle, filled grains percentage, grain yield and benefit. Compared to CK2, the treatment T2 was of good economic and ecological benefits with a significant higher of population panicles by 5.37%, of productive tillers percentage by 18.81%, of filled grains per panicle percentage by 6.88%, of grain yield by 8.72% and of benefit by 4146.15 yuan ha(-1), in addition, it was of an decrease of nitrogen dose by 30%, of fertilizer cost by 261.36 yuan ha(-1) and of irrigation water by 21.7%.