Research On Winter Wheat Soil Water And Nitrogen Transportation Under Light And Small Sprinkler Irrigation

Sprinkler irrigation is an advanced and efficient water saving technology and a relatively advanced water saving method with a rapid development in modern irrigation.Since the light and small sprinkler irrigation units developed rapidly in rural areas, this paper in research applied outdoor field experiments to explore the influences of different irrigation amounts and fertilizing amounts on the winter wheat’s productions and coupling effects of water and nitrogen. Besides, the research designed 3 irrigation levels of 40 mm, 70 mm and 120 mm and 3 nitrogen levels of 150kg/hm2, 300kg/hm2and450kg/hm2 respectively for winter wheat, involving 9 treatments in total. The investigation results were presented as follows:(1)When the unit’s inlet pressure was 0.20 MPa, 0.25 MPa, 0.30 MPa, 0.35 MPa,0.40 MPa and 0.45 MPa, the light and small sprinkler irrigation unit was equipped with a minimum running speed of 10.25m/h and a maximum running speed of 68.40m/h. The greater the pressure and the slower the speed was, the higher the uniformity coefficient of sprinkler irrigation would become. Moreover, the uniformity coefficient of sprinkler irrigation ranged from 87.60% to 91.40%, satisfying the requirements of standards.(2)Under sprinkler irrigation of the light and small sprinkler irrigation unit, the winter wheat’s soil moisture content during the growth period tended to increase with the growing soil depth, but irrigation factor had a declining influence on soils. With a low irrigation amount, the soil moisture content demonstrated little difference before and after the irrigation under W1 treatment.(3)The soil’s nitrate nitrogen concentration would increase with the growing nitrogen amount under the same irrigation amount and different nitrogen amount while the soil’s nitrate nitrogen concentration would decrease with the growing irrigation amount under the same nitrogen amount and different irrigation amount. When the soil layer was deepened, the soil’s nitrate nitrogen concentration would gradually decline and mainly concentrated on the soil layer between 0cm and 60 cm. In addition, the soil layer between 60 cm and 100 cm was equipped with a relatively low nitrate nitrogen concentration.(4) The coupling effects of water and nitrogen affected the distribution of soil moisture and nitrate nitrogen to some extent. Appropriate irrigation and fertilization enabled crops to absorb and utilize the moisture and nitrogen, but excessive irrigationand fertilization would result in the deep percolation of soil nitrogen and underground water pollution instead of helping crops to absorb and use the moisture and nitrogen.(5) Under sprinkler irrigation of the light and small sprinkler irrigation unit in the north Henan province, the winter wheat’s coupling effects of water and nitrogen remarkably influenced the output of winter wheat. Irrigation and fertilization took on a positive correlation, and the coupling effects of water and nitrogen presented an obvious correlation with the winter wheat’s ear length, kernels per spike and yield per unit area.