Research On The Effect Of Water And Fertilizer Coupling For Rice In Black Soil And Chernozem

Heilongjiang province is an important production base of grain in China, and rice as one of the most important food crops in China, has developed rapidly,the scale and level of production increased significantly. However, most of the regions in China have still adopted flooding irrigation so far, which results in enormous loss of water and the balance of groundwater resources damaged seriously. In addition, in order to improve the yield, excessive application of fertilizer also causes serious environmental pollution, which will restrict the development of agriculture in the future. Therefore, it has been a significant research project to develop water-saving irrigation, explore the optimal scheme of water and fertilizer and reduce the waste of water resources as well as environmental pollution on the condition of stable and high yield of rice.This experiment adopts potted method and the optimal design for saturated D311 through comparative analysis, regression analysis, correlation analysis and other methods to study black soil and chernozem rice’s water use efficiency, physiological dynamic, yield and yield components, in different conditions of water and fertilizer management. This paper elaborates the correlation between high yield and the consumption of water and fertilizer, and initially it has been clear about the most suitable ratio of water and fertilizer for the black soil area and chernozem area of rice in Heilongjiang province. The main results were as follows:(1)The rice on the black soil and chernozem transpiration evaporation analysis shows that the most important factor affecting the rice transpiration evaporation is water. Too low soil moisture content will make transpiration evaporation reduced, transpiration evaporation peak and rice’s overall biological dynamic delayed. At last, it will lead to late-maturing rice and reduction. To compare two kinds of soil, we can find that chernozem rice transpiration evaporation is lower than the black soil, and water retention is better than that of black soil. The established model of black soil and chernozem rice water use efficiency shows that all the factors have prominent effects on it. The influence from large to small degree is: N > K > moisture, and the three factors have positive interaction between each other. Through the establishment of water production function model, we can learn that water deficit in different growth period of rice has different effects on the final production, the influence degree from small to large in turn is: green stage < yellow ripeness stage < milk ripe stage < tillering stag < the jointing-booting stage < earing stag.(2) Through the rice crop biological dynamic analysis: different water and fertilizer modes have various effects on the height of plants. Only the plant height is controlled in a reasonable range, high yield of rice could be achieved finally. Unreasonable water and fertilizer mode will cause the plants too high or short, which can lead to reduced rice production. Different water and fertilizer modes, different growth periods of rice have obvious effect in terms of tillers dynamic. Moreover, the moisture is the upermost factor. Suitable water and fertilizer management can effectively enhance tiller number, effective tiller number and percentage of earbearing tiller, which finally achieves high yield.(3)Through the analysis of yield and yield components factor, it is obtained that different factors contribute differently to the output of rice. Through establishing and analyzing the production regression model, we can find that different water and fertilizer management standards have different effects on crop yield obviously, but the influence degree is different, from big to small in turn is N > water > K. And the interaction of the three factors are characterized by positive interaction, which indicates that there is a mutual promotion in the three factors.(4)Best control range in black rice and fertilizer can be determined based on economic yield and water use efficiency:(199.57-215.14)kg / hm2 nitrogen,(56.62-62.29)kg / hm2 potassium. The rate of soil moisture content in late tillering stage accounts for saturated soil water content70.3%-76.7%. The best fertilizer control scheme on chernozem rice is(227.88-239.20)kg / hm2 nitrogen,(59.45-63.69)kg / hm2 potassium. The rate of soil moisture content in late tillering stage accounts for saturated soil water content 73.2%-78.9%.