Study On Water Consumption Of Rice Under Drip Irrigation In Northern Of Xinjiang

Aims:Agriculture production all over the world is facing severe problems of water shortages,and the development of agriculture and economic in China is also constrained by the water shortage.Rice is a crop that need more water.Therefore,One of the important measures to relieve the water shortage is the development and innovation of rice water-saving cultivation technique.In recent years,Xinjiang released rice cultivation method with drip irrigation under mulch,this,method proved effects of water-saving and high-yielding.However,as this system is still in the test stage,there are few studies on its water consumption law,and its water consumption law is not yet clear.In this study,different water gradient treatments were set up to study the water consumption law of rice under drip irrigation at different growth stages and during the whole growth period and the effect on rice growth was studied as well.The purpose of this study is to explore the water-consumption law and the water consumption law at all growth stages of rice under drip irrigation,and then propose the suitable irrigation method for drip irrigated rice in Xinjiang.Methods:The experiment was conducted at the experimental station of Shihezi University from 2016 to 2017.The experiment was conducted using fully randomized design with 3 water treatments and the test rice variety was T-43?Oryza sativa L.C.V.T-43?.Treatment W1:The low limit soil water content is 90%of field capacity and theupper limit of soil water content is 100%of field capacity;Treatment W2:The low limit of soil water content is 80%of field capacity,and the upper limit of soil water content is 90%of field capacity;Treatment W3:The low limit of soil water content 70%of field capacity with upper soil water content 80%of field capacity.Results:1)The irrigation amount of the three treatments was 1303.5 mm,853.1 mm and 659.0 mm,respectively.The period with the largest water consumption of drip irrigation rice was at jointing-booting stage,the largest average daily water consumption and water consumption modulus were also at the jointing and booting stage.2)The water consumption increased with the increase of irrigation amount.There are significant differences in the water consumption of rice between different water treatments.Although the water consumption of W1 treated rice was higher than that of W2 treatment,the harvest index of rice under W1and W2 treatment was the same.3)The amount of irrigation has a great influence on the height of rice under drip irrigation.The leaf area index and SPAD values shows same trend with the height of rice.The high irrigation volume was beneficial to the accumulation of dry matter in drip-irrigated rice under the film.Dry matter increased44.3%and 86.85%in W1 compared with W2 and W3,respectively.4)With the delay of the growth period of rice,the distribution ratio of dry matter accumulation in the leaves and stems gradually decreased,and the distribution ratio of dry matter accumulation in the ear increased gradually.And when the rice under drip irrigation is under severe water stress,the distribution ratio of dry matter accumulation of rice stems is increasing.And when the rice under drip irrigation is in a sufficient moisture environment,the dry matter accumulation ratio of rice panicles increase.5)Water stress results in a significant increase in rice grain stubble percentage,and the number of primary and secondary branch numbers of rice panicles decreased under low soil water content,but the effect on 1000 kernel weight is relative small.The yield of rice under high irrigation amount is also higher.The water use efficiency was W2>W1>W3,and the water efficiency of W2 treatment was higher than that of W1(0.68 kg m^-3)and W3(0.62 kg m^-3)treatments,increased by 19.12%and 30.65%,respectively.The irrigation amount of W2 treatment is much lower than that of W1 treatment,but the water production efficiency of W2 is higher than that of W1 treatment.The irrigation efficiency of W2 treatment is the biggest of the three moisture treatments,which is 0.81 kg m^-3.6)The optimized irrigation schedule is:82.7mm in seedling,198.5mm in booting stage,213.3mm in jointing stage,155.6mm in heading-flowering stage,265.2mm in grain filling stage and 111.1mm in maturaty stage.The optimized irrigation amount in the whole growth period is 1026.4mm.Conclusions:1)The water consumption of rice under mulch drip irrigation under three water treatments is1350.1mm,853.5mm and 651 mm respectively.The maximum water consumption of rice under mulch drip irrigation is at jointing-booting stage.The water consumption of rice drip irrigation under the membrane increased with the increase of irrigation amount,and the yield of rice under drip irrigation under high irrigation amount was the largest.The harvest index is close in W1 and W2,and irrigation water production efficiency and water use efficiency are the largest in W2.2)The optimum irrigation scheme in each rice growth period is:seedling stage 82.7 mm,tillering stage 196.5 mm,jointing stage 213.3 mm,heading to spring flowering period 155.6 mm,grain filling stage265.2 mm and ripening stage 111.1mm,the whole growth period Irrigation is 1026.4 mm..