Effects Of Water Content On Soil Properties Of Jujube Alfalfa Intercropping System

The intercropping system is conducive to improving the comprehensive economic benefits of the orchard.The reasonable irrigation can not only provide the appropriate water and nutrient status,but also avoid the fierce competition of water and fertilizer in the two crops,so as to achieve the purpose of increasing the yield.Therefore,it is possible to more accurately guide the management of alfalfa in jujube and jujube,and to provide the basis for the scientific and standardized development of jujube and alfalfa in the region.The experiment was conducted between 2005 and 2016 at the University of Tarim University Gardening Station and the Highland Cultivation Laboratory of Tarim University.The effects of irrigation at different intervals on soil physical and chemical properties and soil enzyme activities were studied in the intercropping system of fruit intercropping,and the effects of different irrigation capacities on the soil physical and chemical properties and soil enzyme activities were studied.Intercropping alfalfa yield and water use efficiency,the following main conclusions:1.The soil water content in the intercropping conditions showed that the soil water content increased gradually with the depth of soil layer.At the same spacing,the average soil water content of 0-100 cm was the highest at the irrigation rate of 5250m3 · hm-2.The soil bulk density increased with the increase of irrigation amount,the soil bulk density was the lowest under 4 500m3 · hm-2 irrigation,and the soil condition was the best.2.With the development of fertility,the contents of total nitrogen and alkali-hydrolyzable nitrogen in soil were "first increased and then decreased".The content of available phosphorus was "increased first,then decreased and then increased";soil available potassium content increased;Soil organic matter content showed "first drop,then rise".Under the same distance,the contents of total N,available N and available P in the soil were increased with the increase of irrigation amount.Appropriate amount of irrigation could improve the phosphorus and nitrogen supply capacity of the soil,but the irrigation capacity The content of 6000m3 · hm-2 was significantly decreased.The content of organic matter and available potassium decreased with the increase of irrigation amount.3.The intercropping distance and irrigation quantity had different soil enzyme activities,and the activity intensity was different in different periods.The activities of soil urease,sucrase and alkaline phosphatase were "increased first,then decreased and then increased" with the advance of fertility.The activity of soil catalase was decreased and the content of soil polyphenol oxidase was increasing The At the same distance,the soil enzyme activity decreased with the increase of irrigation amount,and the water treatment efficiency of 4500m3 · hm-2 was higher,and the excess water supply was not conducive to the improvement of enzyme activity.4.The annual yield of alfalfa was significantly different under different spacing,and the yield was the highest at 0.5 m spacing.Under the same distance,the dry weight of alfalfa increased first and then decreased with the increase of irrigation amount,The yield was highest under the irrigation of 4500m3 · hm-2,and the yield was the lowest under 6000m3 · hm-2 irrigation.5.From the point of view of water use efficiency,the overall performance of the second crop of the highest,the third crop of the lowest.From the point of view of annual water use efficiency,the water use efficiency of alfalfa at the same distance showed a decreasing trend with the increase of irrigation amount,and the lowest irrigation rate was 6000m3 · hm-2.6.In this experiment,M2W2 was the best,that is,the spacing of jujube alfalfa was 1m,and the irrigation amount was 4500m3 · hm-2,which was the best combination of interval and irrigation.It could not only improve soil nutrient and enzyme activity in jujube and intercropping system.Can get higher alfalfa yield and water use efficiency.The results showed that the intercropping distance and irrigation capacity affected the soil physical and chemical properties and soil enzyme activity of alfalfa intercropping system,and also affected alfalfa yield and water use efficiency to a certain extent.At the same time,Intercropping system of scientific cultivation and irrigation management to provide theoretical reference.