Study On Zizyphus Jujube Water Consumption Character Under Different Irrigation Method In Arid Areas

For the Zizyphus Jujube planting situation at present in Tarim Basin, the traditional irrigation method is furrow irrigation, the irrigation quota is up to 15000-18000 m3/hm2, this irrigation method caused a great waste of water. Therefore, the use of reasonable irrigation measures and irrigation system is the key of conservation and protection of oasis water resources. This experiment takes Aksu region in Xinjiang Province as an example, studies on Zizyphus Jujube water consumption character under different irrigation methods, this provides a scientific basis for reasonable irrigation system of Zizyphus Jujube cultivation in Tarim Basin.In this study, through the use of TRIME, Hydra, Weather Link automatic weather station observations and so on, and using water balance method, based on the analysis of the test with different irrigation methods and optimization of water consumption under the Zizyphus Jujube irrigation system; using principal component regression model to simulate water consumption forecast; to introduce the default model and gray relational analysis model on sensitive factors analyzation of Zizyphus Jujube water consumption, the main results are as follows:(1) Under drip irrigation, water consumption for the whole growth period is 822mm-950.3mm; under furrow irrigation, water consumption for the whole growth period is 964.8mm-1016.1mm.The water irrigation quantity and water consumption quantity has significantly similarity, with the increase of irrigation water quantity, water consumption quantity also has an increasing trend.(2) The optimal drip irrigation system is:total irrigation 18 times, including infancy 1 time, pumping of branch and leaf 2 times, early flowering 2 times, flowering 2 times young fruit 2 times, fruit enlargement stage 7 times, mature 2 times, irrigation quota 375-405m3/hm2·time; Optimal furrow irrigation system is:total irrigation 18 times, infancy 1 time, pumping branch and leaf 2 times, the early flowering stage 2 times, full bloom 2 times, young fruit 2 times, fruit enlargement stage 7 times, maturity 2 times, irrigation quota 420-480m3/hm2·time.(3) Predictive modeling in water consumption, view the results from the model fitting, the regression coefficients all passed by t test, the regression equation passed by F test, and have reached a significant level. The multiple linear regression equation regression coefficients b0, b2, b3 and b4 did not passed t test, so after all the principal component analysis is a good way to predict water consumption. Meanwhile, the principal component analysis can reflect the various factors on the role of water consumption and key decision factors, the main factors of water consumption is:solar radiation and temperature (including the average daily air temperature and daily average soil temperature), followed by daily average relative humidity and daily average soil moisture.(4) Results of water consumption sensitivity factor show that:daily solar radiation and soil moisture, temperature (including air temperature and soil temperature) these three factors are most sensitive factors to water consumption, temperature and soil moisture are the indirect effect of solar radiation. In the process of partial least squares regression model, the equation is clear physical meaning, from the mechanism to explain their contribution to the variable on the dependent variable, and the model is accuracy and reliable, can be used as alternative models for predicting water consumption.