| This study aim to Dengkou semi-desert grassland ecological conditions,based on the local natural environment,support for the field trials,On the basis of the existing irrigation conditions in Dengkou County,study on the corn and sunflower growth index,soil moisture,soil temperature and water use efficiency(WUE)difference for the under Film Drip Irrigation in different irrigation,obtain the water consumption of corn and sunflower each period in drip irrigation under plastic film and from the relationship between yield and water consumption determine each period the sensitive indexes of different models,To finalize based on Jensen model,In order to improve the water use efficiency as the goal of the film under drip irrigation,crop quality, high yield and better irrigation mode. Analysis of the main contents are as follows:1.Analysis the effect of drip Irrigation under film at different water treatment on corn and sunflower plant height,stem diameter,leaf area and grain filling rate,Corn, sunflower plant height and stalk girth was S-shaped growth and change at all growth period.Corn leaf area showing faster growth in the early,in the medium-term is growth slowly,later trends in foliar volume decreasesoverall growth is parabolic;Filling rate of corn and sunflowers with delayed time trend has slowed.2.Soil moisture of corn and sunflower increased with soil depth increases, membrane0～60cm average soil moisture is greater than0～60cm between rows,intermediate corn membrane treatment YM1～YM6moisture content and the line corresponding to each treatment the difference between were1.43%、1.10%、0.99%、2.38%、2.86%、2.75%.Significant differences;Sunflower KH1～KH5difference between the membrane and the lines were1.89%、2.19%、3.96%、2.34%and3.19%;Changes in ground temperature,Soil temperature is higher than the membrane between the lines,changes in soil temperature decreased with increasing soil depth, after the soil temperature is lower than the pre-irrigation irrigation,the day of the diurnal variation of soil temperature occurs hysteresis over time.3.By water balance method to calculate the maize and sunflower crop water requirement.analysis of water law in two crops,Water consumption intensity in tasseling～blossom stage and blossom to filling stage achieve maximum of corn was10.43mm/d,The sunflower’s water consumption and water consumption modulus had peaks at anthesis to filling stage,each processing water consumption intensity range 7.43～7.97mm/d.4.Drip irrigation under mulch corn and sunflower with different water.yield、water consumption and water use efficiency、water consumption is showed two times parabola relationship.And having no synchronization,under certain circumstances the amount of irrigation, the yield with increasing water consumption as increased.when it reaches a certain value.With the water consumption increase the yield will be reduced,increased water consumption to water use efficiency of sensitivity is greater than the yield.with the increase of the amount of water.water use efficiency in the first the yield reached a maximum.5.By testing measured the relative evapotranspiration and relative yield of each crop growth stages.Using the five kinds of crop water production function model which were commonly was used to establish the function relationship,the final analysis determine the Jensen model is the most suitable for irrigation water distribution of different growth stages of corn and sunflower under film drip irrigation.through the Jensen model and the crop water production function.using dynamic programming method for solving the decision variables of crops to optimize the irrigating system of corn and sunflower. Which optimal irrigation of corn in the range of275～300mm, optimal irrigation of sunflower amount is225～275mm. |
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