Research On Optimization Of Drip Irrigation Water Fertilizer Integrated Irrigation Schedule For Maize In Aeolian Sandy Soil

In order to find out the best irrigation schedule of maize under mulch drip irrigation and water integration in aeolian sandy soil area,this paper carried out the following two aspects:(1)In 2018,the experiment of suitable irrigation schedule of maize under mulch drip irrigation in aeolian sandy soil was carried out.The water demand coefficient of 0.4(W1),0.6(W2),0.8(W3),1.0(W4),1.2(W5)and nitrogen application rate(LF:225kg/m2,HF:300kg/hm2)were set to analyze the conventional fertilization and incremental fertilization.The effects of different irrigation water on maize growth,yield,soil water distribution and soil nutrient distribution were studied.(2)Based on the irrigation experiment in 2018,the suitable fertilization rate(300kg/hm2)was obtained.In 2019,the effects of different irrigation rates on maize growth and spatial distribution characteristics of soil water and fertilizer were studied under the condition of one and four fertilization frequency.Through the above two experiments,the better irrigation schedule suitable for drip irrigation under mulch in windy sandy land area was obtained,which provided theoretical basis and technical support for drip irrigation water fertilizer integrated corn scientific irrigation in windy sandy land area.The main results are as follows:(1)With the increase of irrigation amount,LAI,the plant height,stem diameter and aboveground dry matter mass of maize increased gradually.The effect of irrigation amount on maize plant morphological index,dry matter quality,yield and water use efficiency was obvious.Under the condition of 225kg/hm2 fertilization,irrigation had a significant effect on the growth of maize.The plant height,stem diameter,aboveground dry matter quality and yield of maize were significantly lower than those of reclaimed water treatment.Higher growth traits,yield characteristics and water use efficiency of maize could be obtained under reclaimed water treatment or above.(2)Under the condition of 300kg/hm2 fertilization,the effects of irrigation amount on growth traits,yield and water use efficiency of maize gradually decreased,and each irrigation treatment had a certain increase on Maize traits and yield.The results showed that the water content of reclaimed water treatment changed from 70%to 100%of the field capacity before and after irrigation,and the soil water distribution was good;high water treatment was not conducive to improve the content of nitrate nitrogen in each layer,but would significantly reduce the content of nitrate nitrogen;the residual amount of soil available potassium was much greater than the content of nitrate nitrogen,and the greater the irrigation water,the smaller the content of available potassium in the soil depth.(3)Under the condition of 300kg/hm2 fertilization rate and increasing the frequency of fertilization(four times of fertilization),the plant height,LAI.stem diameter and yield of maize increased more in high water treatment than in other treatments,and there was a big difference between low water treatment and other treatments in aboveground dry matter and Yield Traits.The soil moisture content of each treatment decreased with the increase of soil depth.The surface water content of high water treatment was more than that of other treatments before and after irrigation.The results showed that the increase of appropriate irrigation amount was beneficial to improve the content of nitrate nitrogen in each layer;the content of available potassium first decreased slightly and then decreased significantly with the growth period,and the content of available potassium in low water treatment was higher than that in other treatments in each period.(4)According to the growth physiology,yield and distribution characteristics of soil moisture and nutrients,the amount of fertilizer was300kg/hm2.The results showed that the plant height,leaf area index and yield of four times fertilization treatment were higher than that of two times fertilization treatment.The plant height,leaf area index and yield of seven times fertilization treatment were higher than that of two times fertilization treatment.The yield of seven times fertilization treatment increased by about 10%,and the uniformity of water distribution was higher,the content of soil nitrate nitrogen remained more,the content of nitrate nitrogen and available potassium distributed more evenlyIt is suggested that drip irrigation system is more suitable for Maize in this area.lt is suggested that 300kg/hm2 pure nitrogen fertilizer should be applied in 4 times of water dissolving drip irrigation in Northwest Liaoning sandy soil area.The amount of water treatment should be controlled(0.8 KciET0,irrigation divided into two in seedling stage was 32 mm.irrigation divided into three irrigation in jointing stage was 46 mm,irrigation divided into four at ear stage was 88 mm.irrigation divided into three irrigation at grouting stage was 62 mm,irrigation at maturity stage once was 19 mm)is the best irrigation schedule in this area.