Study On Root Distribution And Water Uptake Model Of Walnut Tree At Drip Irrigation Condition In Arid Area

Arid zone of northwest China region vast, low and uneven distribution of water resources, waterresources shortage has become the northwest arid region the main problems of agricultural sustainabledevelopment. Straightforward way of agricultural irrigation is serious waste of the already scarce waterresources, the implementation of water-saving agriculture, under the trend of the Walnut Tree plantednorthwest arid areas at present, the red flag slope farm planting Walnut Tree in Xinjiang Aksu area as theresearch object, research under the condition of drip irrigation Walnut Tree root system distribution andwater law, counsel for the northwest arid region features of walnut industry provide theoretical basis for thescientific management. This experiment adopts TRIME-IPH soil moisture meter on Walnut Tree root zonesoil moisture content monitoring, TDP Walnut Tree transpiration, miniature probe type flow metermonitoring evapotranspiration monitoring surface soil evaporation between Walnut Tree, Watchdog smallstations daily monitoring meteorological data, using stratified sublevel mining method study of Walnut Treeroot system distribution, etc. Choose in test on the basis of improving Feddes model, to simulate the waterabsorption of root soil water dynamics and to verify the accuracy of the model. Main research contents areas follows:(1) This paper introduces a kind of based on image on the canopy leaf area index of the volume issimple measuring method, and to validate the method with traditional method, the results show that betterpracticability.(2) Walnut Tree root zone soil water variation and water consumption calculation and error analysis,the results show that trees root zone soil water content variation of base is equal to the plant transpirationby evaporation. On the relationship between the trees transpiration rate and meteorological factor directlyanalyzed and fitting, the result shows that trees transpiration rate and has a good relationship betweenmeteorological factors.(3) The measured Walnut Tree root, the root system distribution characteristics were analyzed. Resultsshow that the Walnut Tree root in horizontal direction are mainly distributed in0-120cm range, accountedfor90.84%of total root system distribution. In the vertical direction are mainly distributed in0-90cmrange, accounting for78.75%of the total length of root distribution. Relatively effective root density inhorizontal direction in a polynomial function fitting and exponential function in the vertical direction on thee fitting, and the fitting precision is higher.(4) Walnut Tree root water absorption rate and transpiration, effective root length density and rootzone soil water potential are closely related. With the improved Feddes model Walnut Tree root waterabsorption model is established. According to the principle of soil water dynamics, to validate this paperestablished root water absorption model, results show that the model can reflect the actual Walnut Tree rootwater absorption, has certain use value.