Effects Of Drip Irrigation Water Tempreture On Cotton Growth And Gray Desert Soil Environment

Regarded the gray desert soil of Northern Xinjiang as experimental soil and the cotton as experimental object,the drip irrigation technology was adopt by this study through the combination of soil-box simulation experiment,water planting experiment and field trial in order to establish the coupled heat-fluid transport model.It shall confirm the influences of irrigation water temperature on physiological ecology of cotton,nutrient absorption and yield as well as on the nutrient of gray desert soil and edaphon by the drip irrigation method.The experimental results show:（1）through the soil-box simulation experiment,the coupled heat-fluid digital model has relatively good simulation effect in the established drip irrigation conditions.After mastering some soil and meteorological data,this digital model can be taken advantage of to predict the soil water and thermal environment conditions required by the crop growth in the surface drip irrigation conditions.In addition,the numerical simulation value and measured results both indicate that there is the greater influence of irrigation water temperature on surface soil temperature in the surface drip irrigation conditions.（2）The water planting experimental results show:in the early blooming stage,the cultivation with temperature-added water can effectively increase the activity of SOD,CAT and POD as well as reduce the content of MDA with the obvious increase of root active uptake area.Leaves antioxidant enzyme activities and root absorption capacity were inhibited obviously in boll stage.（3）The field trial finds that compared with the well-water drip irrigation,the temperature-added water drip irrigation can promote the cotton growth and the accumulation of biomass,thus the distribution pattern of biomass will change.Meanwhile,this drip irrigation method is also able to enhance the absorption of plants to the nutrients.Compared with the well-water drip irrigation,the whole plant of cotton N with this method increases the absorptive amount by 57.4%（P<0.01）.Except it is slightly reduced in the stem for the absorption of P₂O₅,the rest of parts all increase,and the absorptive amount of P₂O₅ in bell-shaped organ is increased by 33.0%（P<0.05）.Besides,the absorptive amounts of P₂O₅ in root,stem,leaves and bell-shaped organ of cotton are respectively added by23.62%,53.81%,62.99%and 33.95%with the obvious amplification in the stem and leaves（P<0.01）.Through the drip irrigation method with temperature-added water,the cotton bell number is increased by 18.54%,the single bell weight is decreased by8.86%and the yield of seed cotton is added by 7.29%.（4）In the temperature-added water drip irrigation,the effective nutrients in the 0-20cm soil are slightly lower than that in well-water drip irrigation,in the bud stage,soil available N content of ZW treatment was reduced by 13.51%（P<0.05）than CK,in the boll stage,soil available P was reduced by 26.7%（P<0.05）,which shows the temperature-added water drip irrigation can promote the absorption of cotton to the soil nutrients.In addition,after the temperature-added water drip irrigation,the quantities of bacteria,fungus and actinomyces are all increased,After third days of irrigation,bacteria,fungi and actinomycetes increased by 41.5%（P<0.05）,45%（P<0.01）,19%（P<0.05）,Besides,in the fifth day after the drip irrigation,the number of actinomycetes was increased by 93.2%（P<0.01）.From the research results above,it is known that the temperature-added water drip irrigation can promote the growth of cotton and the absorption to the effective nutrients of the soil as well as increase the microbial population in the soil so as to improve the soil fertility.