| In view of the shortage of rainfall in the semi-arid areas of Guanzhong,Shaanxi,the spatial and temporal distribution is seriously uneven,the main research object is the specific fruit-kiwifruit of Shaanxi Guanzhong.In the whole growth periods of kiwifruit trees,the research designs different irrigation treatments,which are based on the real-time dynamic change of soil water in kiwi garden.The research analyzes the affection of the different irrigation treatments on kiwifruit's water need and consumption rule,physiological and ecological index,fruit quality index,yield, water use efficiency and economic benefit evaluation; To study, and establishes the most suitable irrigation system of kiwifruit under drip irrigation,provide the theoretical basis for the cultivation of semi-arid area in Guanzhong area of Shaanxi province sustainable development type water saving, high quality and high yield of kiwifruit trees, stable and efficient. The main results of the study are as follows:(1) The soil temperature at different depths showed a maximum value, a minimum value and an average value. With the increase of soil depth, the change of soil temperature gradually decreases.The soil temperature at the same depth decreased with the increase of irrigation quota,the performance of the continuation of time as the first increase and then reduce the trend in the whole phenophase stage.With the increase of soil depth,soil temperature showed a tendency to changed from big to small, then back to big again. Temperature is the main factor affecting the soil temperature, but not the only factor affecting the soil temperature, other factors still need to be explored.(2) According to the study of soil moisture distribution characteristics under different irrigation treatments,it was found that under the condition of drip irrigation,the soil moisture content increased with the increase of irrigation quota.Different irrigation treatments significant difference of soil moisture content in kiwifruit,and the differences between different layers are also very apparent,the change of soil moisture content scope is larger,the biggest can reach 22.84%,the smallest only about 9.13%.The trend of soil water consumption among different irrigation quota treatments was less than that of full irrigation treatment.In a certain water supply range,and there was a positive correlation between water consumption and water supply in kiwifruit trees.(3) In 2016,in the whole growth periods of kiwifruit trees,quantity of reference crop evapotranspiration is high at both ends and low trend among them,and the peak position was centered. The relationship between the daily water consumption intensity of the kiwifruit tree is:the fruit enlargement growth stage > the flowing and fruit-setting stage > the sprout leaves stage > the fruit maturing stage, and the daily water consumption intensity increases with the increase of irrigation quota, the flowing and fruit-setting stage is the critical period of the kiwifruit trees in the all growth periods, and this stage is extremely sensitive to water deficit.kiwifruit crop coefficient in the whole stages the change trend of first increases then decrease,the peak, the whole growth period of crop coefficient of the mean value of 0.93.Fruit mature period crop coefficient is the largest,crop coefficient of minimum exhibition leaf bud period.The kiwifruit tree crop coefficient had a good quadratic polynomial relationship with > 10?accumulated temperature.Under similar climatic background conditions,the crop coefficient of kiwifruit trees could be roughly estimated by combining the known temperature >10 ?.(4) Through the study of kiwifruit trees the ecological index found that different growth indicators of different irrigation treatments on kiwifruit trees have more significant effect.New shoot length and coarseness, leaf blade length,transverse diameter and leaf area index,petiole length and coarseness,the longitudinal diameter and transverse diameter of the fruit were affected by different degree of inhibition or promotion.The fruit drop rate of kiwifruit decreases with the increase of irrigation amount,but after a certain threshold range, the fruit drop rate increases slightly with the increase of irrigation amount.In a certain range of irrigation,kiwifruit weight and yield are increased with the increase of irrigation.Under the mild deficit,the yield of kiwifruit was not significantly reduced,the water use efficiency was also improved,and the fruit quality was the best.(5 ) The water production function model of the whole growth period of kiwifruit trees was established by through analysis of yield and water consumption and demand under different irrigation treatments.The results showed that the yield and water consumption and demand showed a good polynomial function relationship,and the coefficient of determination was above 0.9, the fitting relationship is better, the correlation is better.The Jensen model was used to solve the crop water production function of kiwifruit trees in different growth periods,and the moisture sensitivity index of each phenophase was obtained.The order of the moisture sensitivity indices is: the fruit enlargement growth stage > the flowing and fruit-setting stage >the sprout leaves stage > the fruit maturing stage,the results are in good agreement with the actual situation in the experiment. Because of the serious shortage of water resources available for irrigation in semi-arid areas of Guanzhong,Shaanxi, the maximum water requirement of crops at different phenological stages can not be fully satisfied,therefore,the irrigation system can only be implemented under the condition of non full irrigation,and the comparative analysis shows that the optimal irrigation group is the mild deficit irrigation treatment.(6) According to the analysis of the water consumption and demand,growth and physiological morphology,fruit quality,yield,irrigation water use efficiency and economic benefit of the kiwifruit trees by drip irrigation under different irrigation quota treatment. This paper puts forward the most suitable and efficient water-saving irrigation system in the semi-arid area of Guanzhong,Shaanxi in 2016( a normal flow year),which is the irrigation quota of 3080m3/hm2 during the whole growth period and 14 times of drip irrigation. |
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