The Studies On Coupling Effects Between Water And Nitrogen Of Maize In West Semiarid Region Of Heilongjiang Province

The west semiarid of Heilongjiang province had the enormous production potential and the important station in Heilongjiang. But the lacking water resources was the primary factor. Fertilization unreasonable is one of the main reasons restricts potential of water,under the controlled condition, fertilization can greatly improve crop water use efficiency. Therefore people more and more attend to the relation of the water and the nutrient in the dryland farming.According to the field experiment made in Gannan County, Heilongjiang Province in 2007, researched the effects of water and nitrogen fertilizer cooperation on growth and development, yield and the water consumption of the maize in northeast semiarid region.When researched coupling effects between water and nitrogen fertilizer, four kind of water levels as whole growth period of wet, the suitable water, mild drought, moderate drought, separately making up with four levels of nitrogen fertilizer from low to high. It was 16 kinds of treatments. It analyzed the impact of different water treatment, different nitrogen fertilizer treatment, as well as coupling effects between water and nitrogen on maize growth and development, yield and water consumption. Separately set up the regression model between yield or water consumption and water nitrogen. It showed that water and nitrogen had significantly positive coupling effect on maize yield and reasonable application of nitrogen fertilizer increased transpiration, reduced evaporation. Finally, for each water level reached ideal water production function of maximum yield.When researched function of water stress,a moderate drought treatment for each growth stage (in this experiment,corn growing stage be divided into 4 growth stages as seedling,jointing, tasselling, grain filling) respectively separately making up with four levels of nitrogen fertilizer from low to high. It was 16 kinds of treatments. These treatments were compared with the whole growth period of suitable water. The results showed that: the growth and development and yield will be affected to a certain extent at water stress of different growth stages, but the extent was different. Using the gray correlation analysis method of gray system theory to evaluate experiment disposals of deficit irrigation,and concluded that the effects of water stress at the seedling stage and filling stage impacted on irrigation efficiency,less than at the jointing stage and tasselling stage,increased amount of nitrogen fertilizer could improve irrigation efficiency of maize.When research the relationship between yield and water consumption, has analyzed all of 32 kinds of treatments. Under the background of the lacked water resources, the restricted agricultural irrigation water and the increaser foodstuff requirement, determined irrigation system at the west semiarid region of Heilongjiang Province. The first thing was to consider irrigation costs and yield, and then to decide the allocation of irrigation water consumption of time and quantity, so that the irrigation benefit was highest. First of all, studied the relationship between maize yield and water consumption of whole growth period, and set up the regression equation between maize yield and water consumption of whole growth period under the conditions of different nitrogen fertilizer. Has determined optimized interval upper and lower limits of water consumption; Then has calculated economy irrigation ration under the conditions of different nitrogen fertilizer; Finally studied the relationship between maize yield water consumption of each growth stage,using Jensen model calculate water sensitive index under different conditions of nitrogen fertilizer in each growth stage. According to the water sensitive index, adopted the calculated software of the LINGO of the non-linear programming model to accomplish optimum distribution of limited water during the different growth stages of the maize. In the condition of gaining the same yield, the irrigation by the method could save the water quantity compared with actual irrigation.