Study On The Efficient Utilization Of Water And Nitrogen In Spring Wheat By Drip Irrigation In Gravel Sandy Soil

At present,there are many problems in Xinjiang wheat planting,such as large input of water and fertilizer,low utilization efficiency and serious loss.Therefore,based on the experimental data of wheat field for 2 years of drip irrigation,Effects of different Irrigation quota of 37.5mm、45mm、52.5mm、60mm(W1、W2、W3、W4、W5)and nitrogen Application level of 0、110 kg/hm~2、179 kg/hm~2、248 kg/hm~2、317 kg/hm~2(N0、N1、N2、N3、N4)on wheat growth,yield,soil nitrate transport,nitrogen balance and water and nitrogen absorption and utilization efficiency.the mechanism of water and nitrogen efficient utilization was explored under the condition of Gravel Sand in Arid area and reference of spring wheat water-nitrogen coupling system was provided.The results showed that:(1)The wheat irrigation quota of 45mm～60mm(W3 treatment～W5 treatment)and the total nitrogen application rate of 179kg/hm~2～248kg/hm~2(N2 treatment～N3 treatment)were beneficial to the growth of wheat plant height..The best treatment for dry matter accumulation in wheat was the irrigation quota of 45mm and the amount of nitrogen applied for 248mm(W3N2 treatment).In this treatment,the amount of nitrogen applied continued to increase,or the amount of irrigation could not increase the dry matter significantly.The absorption of nitrogen in wheat was mainly in the early stage,but only a small amount of nitrogen was absorbed in the later stage.From jointing stage to heading and flowering stage was the peak of wheat daily absorption and the daily absorption was1.5kg/hm~2～4.32kg/hm~2.Irrigation quota in 45mm～52.5mm(W3 treatment～W5 treatment)and total nitrogen application amount in 110kg/hm~2～179 kg/hm~2(N1 treatment～N2 treatment)were beneficial to the nitrogen absorption of wheat plants.(2)When nitrogen application was more than 248kg/hm~2(N3)and the amount of nitrogen was increased,grain yield increased not significantly,even decreased,and the nitrogen absorption of grain was affected.Comprehensive two years data analysis,irrigation quota in 45mm～52.5mm(W3treatment～W4 treatment)the amount of nitrogen at 179kg/hm~2～248kg/hm~2(N2 treatment～N3treatment)at the same time to increase the yield components and yield was the most beneficial.(3)The water consumption modulus of wheat treated with different water and nitrogen treatments were similar at each growth stage.On the whole,the water consumption and water consumption modulus of each growth period of 2 years were as follows:heading stage,filling stage>jointing stage>tillering stage,mature stage>seedling stage.Daily consumption of water of two years fluctuated in the range of 3.28mm～7.71mm.(4)In 2016,the irrigation volume of 15 treatments was 285mm～525mm,and the water consumption was 259mm～369mm.In 2017,the irrigation volume of 9 treatments was285mm～495mm,and the water consumption was 226mm～319mm.The increase of irrigation amount in 285mm～390mm(W1 treatment～W3 treatment)could effectively increase the water consumption of wheat.The amount of irrigation water was more than 390 mm(W3 treatment),and most of the water was lost because of deep leakage.Under the same irrigation level,the increase of nitrogen application rate in the range of 0～248.34kg/hm~2(N0 treatment～N3 treatment)promoted the consumption of water consumption of wheat,and the increase of nitrogen application amount in the range of 179.34kg/hm~2～248.34kg/hm~2(N2 treatment～N3 treatment)could effectively promote the consumption of wheat water consumption.The amount of nitrogen applied was more than248.34kg/hm~2(N3 treatment),and the increase of nitrogen had no significant effect on the water consumption of wheat,and even inhibited the water consumption.(5)The nitrate nitrogen content in each growth stage showed a decreasing trend with the depth.The maximum value of nitrate nitrogen content of each treatment at each growth stage appeared in0～20cm.Nitrate content in 0～60cm increased with the increase of nitrogen application rate.The fluctuation range of nitrate nitrogen in different growth stages of 80cm～100cm soil layer was not different.When the irrigation amount was more than 390mm,most of the water was lost because of deep leakage,and a large amount of nitrate nitrogen was leached with the leakage of water.In this experiment,the leaching loss was the main way,most of nitrate nitrogen was washed into the deeper soil with water leakage,and the leaching of nitrate nitrogen was more serious with the increase of nitrogen application rate.(6)The results of 2 years experiment showed that the combination of water and nitrogen with179kg/hm~2～248kg/hm ~2,irrigation quota 40mm and total irrigation quota 390mm～405mm had lower apparent loss,higher yield and higher efficiency of water and nitrogen absorption and utilization,Which was the best combination of water and fertilizer suitable for gravel sandy soil in arid area.