| Winter wheat is one of main crops in our country, by research on soil moisture and wheats' physiological and ecological dynamic index change and its relationship under field conditions in wheat's main growth stages, the effect regularity of soil moisture on the physiological and ecological index of wheat is confirmed, the research aim of this thesis is afford scientific evidence for water-saving irrigation of winter wheat.The three-year research results are below:1. For winter wheat in 0-20cm, 20-40cm, 40-60cm depth in soil layer throughout the whole growth stage, the highest soil water content(SWC) is in presowing stage, while a continuous decreasing of that was seen after sowing before a slight restoration in flowering to filling stage except 0~20cm depth. With the aid of regression analysis simulation models were developed in each winter wheat treatment through all growth stages, which is expressed as equation W=c/(l+em'b')for wheat between W(SWC,%) and t(days after sowing)2. Plastic covering is effective to save water and augment yield for winter wheat By plastic covering winter wheat, denuded area is decreased, water evaporation is prevented effectively and soil moisture is improved, then improved moisture comes into being, and the smaller quantitative invalid raining water flows to the two sides of the ridges by the film and permeated to the root of the wheat through the hols of the seedlings, which changes the invalid the invalid raining into the valid, and it improve the utilization efficiency of the natural raining, plastic covering can improve leaf water potential and augment the utilization efficiency to the soil moisture of the winter wheat. During shooting period ,ear bearing periodand filling period ,the average photosynthesis rate of a day of the plastic covering wheat is higher than that of the wheat without film by 24.5%, 34.15% and 12.79% accordingly. In 0-40cm soil layer the soil moisture of the plastic covering field is higher than that of the field without film by 4%,1.5% and 3% accordingly during seeding period .over-wintering period and shooting period. Plastic covering can resist drought and preserve soil moisture ,it can make winter wheat grow faster and augment the intensity of photosynthesis of the field, which is helpful to the accumulation of the organic nutrient ,and it is very meaningful to relieve drought condition and augment yield.3. The effects of FA on water-saving ,drought resistance and augmenting yield of the winter wheat.The yield of the treatments with FA is higher than that of contradistinction. FA application can make winter wheat hold some amount of leaf water potential ,and improve the drought resistance of the winter wheat, and it's meaningful to water-saving irrigation. FA improves the water balance condition in the plant body by regulating and closing pore of leaves, decreasing water transpiration diminishing the rate of consuming water and retarding the deficit of winter wheat ,which make the good water potential condition and percent moisture be held between soil and plant. Obviously, FA application has a positive effect on some physiological indexes of winter wheat ,it fulfill its effect of water-saving and drought resistance by improving some physiological indexes of winter wheat .4. The effect of different irrigation system on growth physiology and ecology of the winter wheat. The leaf water potential of three-time irrigation is higher than that of two-time one, what's more, the water potential of three-time irrigation is stable, and it can ensure water provision in all the growth stages for wheat, the water potential of one-timeirrigation is lower, and the water potential of irrigation according to time is higher than that of one-time irrigation. The irrigation of the winter wheat should be during the key periods, the irrigation effect is better to irrigate the wheat once during turning green period ,ear bearing period or filling period .The irrigation once dur...
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