Effect Of Water And Fertilizer Coupling On Nitrogen, Water Use Efficiency And Yield Of Rice

In this paper, taking rice variety Liaojing 212 as entry, the experiment was conducted by using three nitrogen levels and three irrigation methods to study the yield, economic traits, tillering and high height dynamic, growth and development progress, photosynthetic characteristics, water use efficiency, utilization rate of nitrogen fertilizer, and the relationship between nitrogen levels and irrigation methods. It will provide theoretical reference for establishing "water and nitrogen coupling" high-yielding rice production system and realizing low cost and high yield of rice. The results were as follows:Low nitrogen treatment N1(155kg/ha) and shallow-wet-dry intermittent irrigation had the highest yield of 12.05 t/ha in nine treatments, higher than N2W1,N2W2,N2W3 treatments, with the yield increase by 10.2%,5.4% and 18.2% respectively. The higher yield of N1W2 treatment resulted from higher 1000-grain weight, the effective panicles and more grain per panicle. Except N0W1,N0W3, the kernel settings of other treatments were more than 90%.With the increase of nitrogen application, the tiller number and plant height of all treatments were increased, however, the effective panicles were increased first and then decreased. The tillers in continuous flooding irrigation treatment W3 were more than those of Wl and W2, but the effective panicles were less. Meanwhile, N1W2 treatment extended rice growing period for more than five days.The leaf area index in treatment N1W2 reached 9.6 at full heading stage and still keep higher at maturity stage, which was beneficial to promote photosynthetic efficiency of leaves. And the dry matter accumulation in this treatment was more than 100g.The higher transpiration rate but lower photosynthetic treatment W3 led to lower water use efficiency.N1W2 and N1W1 treatments had higher water use efficiency than other treatments.Lower nitrogen treatment N1 improved the agronomic utilization efficiency of nitrogen, and the treatment of N1W2 had the highest nitrogen partial productivity. In reasonable water and nitrogen coupling treatments, the application of low nitrogen rate did not reduce yields but even increased yield, showing that water and nitrogen coupling mode is helpful to build high-yielding population, reduce pesticide use and cost, and realize environment stewardship and sustainable rice production.