Growth And Water Use Efficiency Of Spring Maize Under Soil Moisture Control In Shihezi Region

Xinjiang is mainly dominated by oasis irrigated agriculture.Agricultural water consumption accounts for more than 94%of the water supply.The shortage of water resources and the low efficiency of irrigation water restrict severely the sustainable development of oasis agriculture and threaten the ecological security of oasis.Therefore,it is of great practical significance to carry out research on the lower limit of soil moisture suitable for crop growth in order to improve the efficiency of water resources utilization and ensure the sustainable development of oasis agricultural ecological environment.Three lower limit levels of soil moisture control at three different spring maize growth stages(jointingtasseling stage,the flowering-grouting stage,and the milky ripe-full ripe stage)were investigated.The lower soil moisture limits were based on percentages of the field capacity(FC),there were nine treatments were set up by orthogonal test design,these were the jointing-tasseling stage:60%,75%,and 90%of FC;the flowering-grouting stage:60%,75%and 90%of FC;and the milky ripe-full ripe stage:50%,60%,and 70%of FC,each treatment repeated three times,each treatment repeated 3 times.Then the impacts of the soil moisture lower limits on the field environment,and maize growth,yield,and water use efficiency(WUE)were investigated,so as to determine the high-efficiency water resources and water-saving technologies which was the minimum level of soil moisture control suitable for different development stages of spring maize.The research results were showed as follows:(1)Soil moisture,field temperature and humidity,and soil respiration had different response characteristics to the lower limit of soil moisture in different development stages.The results showed that the effect of the appropriate lower limit of soil moisture on the moisture content of different soil layers and the temperature and humidity between rows was beneficial to the growth of maize,and increases the field soil respiration rate during the middle and late growth of maize.(2)There were significant differences in spring maize plant height and dry matter accumulation above ground during different water control lower limit treatments in joint-tasseling stage,but there was no significant difference in leaf area,yield indexes and yield.Under the condition of 60%FC in jointingtasseling stage,90%FC in flowering-filling stage,70%FC in milk ripening-maturity stage,spring maize plant height,leaf area,dry matter accumulation above ground,single leaf water efficiency and yield were the highest.By establishing a fitting curve of water consumption and spring maize yield,and a fitting curve of water consumption and spring maize WUE,the water consumption required for maize growth under the highest yield and the highest WUE was 570.68mm and 540.27mm,respectively.(3)The lower limit of soil moisture was controlled at 60%FC in jointing-tasseling stage,90%FC in flowering-grouting stage and 70%FC in milky ripe full ripe stage,and spring maize had the highest WUE,yield and benefit.Compared with the control treatment,the WUE in the growing period of maize had increased by 18.84%,saving irrigation water by 15.08%and adding economic benefits of 689.52 yuan/hm2.