Effects Of Water And Fertilizer Coupling On Nutrients Absorption And Yield Of Rice In Cold Area

Soil moisture and nutrient are the principal factors affecting rice yield. Elucidation of their influences and coupling effects on grain yield formation of rice would have great significance in conducting the cultivation for high yielding, good qulity and high efficiency. In this study, plot experimen was designed to study the effects of control irrigation, site-specific nutrient management on nutrient absorption and yield formation of rice. The main results are as follows:1.Under the condition of traditional irrigation, compared with farmers′fertilization practice (FFP), earbearing tiller rate of rice of site-specific nutrient management (SSNM) increased 9 percent point.Under the same condition of FFP, compared with traditional irrigation, earbearing tiller rate of rice of control irrigation increased 6 percent point.The statistic analysis showed significant difference at 0.05 level. By increasing LAI after heading, earbearing tiller rate and grain–leaf ratio, interaction between control irrigation and SSNM are the necessary factors of forming rice healthy gpopulation, which is significant for high yield of rice.2. The different fertilizer treatments have great influence on increasing N and K content of rice. The effects of different irrigate way on P content of rice are significantl. P content of rice in traditional irrigation is higer than that in control irrigation, and interaction between control irrigation and SSNM improved nutrients accumulation of rice significantly. All kinds of nutrient accumulation mainly occurred during the panicle initiation to heading stage. In this time, N accumulation and percentage of it to total N accumulation is at 61.6%～68.9%, P at 76.2%～81.3%, K at 61.1%～85.5%, and average rate of N absorption was 2.1 kg·hm^-2·d^-1, K was 3.0 kg·hm^-2·d^-1。3. Rice dry matter accumulated mainly during meiosis to milky maturity, in which dry matter accumulation and percentage of it to total dry matter accumulation was 57%～65%,the highest accumulated rate was 208.7kg·hm^-2·d^-1. Interaction between control irrigation and SSNM improved the total rice dry matter accumulation significantly,and improve rice yield. Under the condition of control irrigation, applying appropriate amount of N at meiosis stage has an obvious effecet on improving rice dry matter accumulation. At the same time, this research also finds that there is a significantly positive correlation between rice dry matter accumulation after heading and rice yield.4. Based on SSNM, by controlling the total N input, assured adequate N supply, as well as avoid over supply. N input was reduced at early tillering to midtillering to control invalid tiller. Control irrigation increased soil ventilation, and root and leaf of rice have higher activity after...