| Large area of economic forest plantation in hilly region of the Loess Plateau is the leading industry,which is to deal with the large area of cultivated land decreased and promoting economic development after the national Grain for Green project.But due to the low rainfall and the intense of evapotranspiration of Jujube result to the water supplying and demanding in contradiction.Additionally,drought and lack of water and the uneven spatial and temporal distribution of rainfall have result in severe soil water stress,low yield,poor efficiency,which effect the sustained and healthy development of ecological economic forest.In this study,the combination of fish-scale pits and different mulching measures.was used in the mountain jujube economy forest.Through the method of long-term simulation monitoring,field sampling and mathematical statistics and model,the soil moisture,rainfall infiltration and jujube water consumption under fish-scale pits and mulching measures were studied systematically.Here,we study the mechanism of soil moisture conservation measures in different fish-scale pits and mulching measures and clarified the main driving factors of jujube transpiration under different time scales and present a fast and effective method for estimating the evapotranspiration of crops and established the ecological hydrological process model of fish-scale pits and mulching measures.The research can provide scientific basis for the optimal management of orchard water under limited water resources.(1)The study cleared the effects of fish-scale pits and mulching measures on the physical properties of soil.The structure of fish-scale can collect fine particles and sand grains carried by slope runoff and runoff and improve the content of soil particles and sand grains in the surface of fish-scale pits.Due to the silt and sand clogging the soil pores,resulting in the increased of soil bulk density,and the decreased of porosity,and the decreased of saturation and unsaturated conductivity and saturated water content,the fish-scale can significantly increase the soil organic carbon and total nitrogen content,and improve soil structure,and decreased soil bulk density and increase porosity,saturated and unsaturated hydraulic conductivity and significantly improved saturated water content.(2)The study analyzed the spatial and temporal changes of soil water and the characteristics of different fish-scale pits and mulching measures.Compared with the bare control,the fish-scale pits and mulching measures can effectively inhibit the precipitation and inhibit evaporation;and there was no effect on the soil water storage of 100 cm or above during the whole growth period;and various processing in drought years soil water deficit,further PingShui year except bare land control treatments in a 40-160 cm soil layer soil water deficit,further the rest processing showed different degrees of compensation characteristics.(3)Study evaluate the effects of jujube stem sap flow rate under different time scales of the fish-scale pits and mulching measures and clear the effects of main meteorological factors of jujube stem sap flow rate.Under different fish-scale pits and mulching measures of jujube stem sap flow rate showed consistent variation.After typical rainfall sap flow rate reached the peak in the first day after the stem.The stem sap flow rate of jujube under fish-scale pits measure was significantly higher than that of fish without cover and bare land control measures.Through partial correlation analysis,air temperature,air relative humidity,photosynthetically active radiation and vapor pressure deficit is the main influencing parameters for the stem sap flow rate of jujube.And study constructed the multivariate linear and stepwise regression model,basing on meteorological factors and stem sap flow rate of jujube under different fish-scale pits and mulching measures.(4)The use of water automatic monitoring device to estimate rainfall infiltration method and jujube water consumption,and based on this method,analyzes the influence of different vegetation mulching measures on jujube water consumption.The method of high precision time,can accurately capture the jujube water consumption process;in drought period estimation is more accurate,the overall error in the acceptable range,is a new method to estimate a wide applicability of crop evapotranspiration.By using the calculation method of different fish-scale pits and mulching measures under rainfall infiltration,soil evaporation and evapotranspiration of jujube,the results show that the amount of rainfall infiltration the fish-scale pits measures are significantly higher than that of bare land control measures.In the period of concentrated rainfall,it showed strong ability in the rain;and during the whole growth period,fish-scale pits with mulching reduced soil surface evaporation,and significantly increased the transpiration of jujube fruit period and fruit enlargement period.(5)Based on Hydrus-1D,study constructed different fish-scale pits measures of ecological hydrological cycle process model based on and analyzed the influence of different methods on the dynamic process of rainfall infiltration,evapotranspiration and soil water storage.On the basis of the soil water dynamics theory,considering with the soil water movement characteristics under the condition of fish-scale pits,using two kinds of parameter inversion rates on soil water movement parameters,the results of the test,dynamic changes of soil moisture can accurately reflect the rate of soil water movement parameters obtained by the MCMC-DREAM method and distribution.By constructing a model of eco hydrological process in different scale combination measures covering jujube under simulated fish found no coverage significantly increased rainfall infiltration and evaporation,increase soil water storage pit after the rain;straw mulching could significantly reduce soil evaporation,increase jujube transpiration,improve the whole growth period of soil Soil water storage. |
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