Study On Effect Of Water Deficit On Growth,water And Nitrogen Utilization Of Drip Irrigation Cotton

This study to explore drip irrigation cotton RDI critical period,make water drip irrigation cotton high yield and nitrogen utilization strategy,the 2016-2017 in changji hui autonomous prefecture,xinjiang manas county town and village field,6 families in new land early 45,for materials,in drip irrigation cotton growing season of the whole irrigation period of operation,set different water deficit during the period of field trials.The effects of water deficit on the growth,fine-root biomass,turnover,yield and water nitrogen utilization efficiency of drip irrigation cotton were studied.The main results were as follows: 1.Effect of water deficit at different periods on fine-root dynamics of drip irrigation cotton ?Objectives? The experiment was to explore the effects of water deficit at different periods on fine-root dynamics of drip irrigation cotton.The proper mode of drip irrigation period of water deficit was studied in this paper.?Methods? Single factor field experiment was conducted.A CI-600 root growth monitoring system was used to measure changes in fine-root length and diameter.Calculations were done to determine fine-root growth rate(A),mortality rate(D),and the ratio of growth rate to mortality rate(RAD).The data were then compared to determine the influence of irrigation method on fine-root growth,mortality,and turnover.?Results?(1)Fine-root biomass reached a maximum and then declined under all treatments.And the maximums were all in the full bolling period.The maximum of fine-root biomass of K-F-F,F-F-K and K-F-K treatments compared with CK treatment was not significant difference.(2)Water deficit of the squaring inhibited the growth of fine-root.After rewater,the growth rate will increase rapidly,which didn't have a significant effect on the peak of fine-root biomass;Water deficit of the early boll-setting inhibited the growth of fine-root.After rewater,the peak value of fine-root biomass is still lower than CK;Water deficit of the late boll-setting promoted the death of fine-root,and the fine-root biomass decreased rapidly;The effects of water deficit in multiple continuous periods on the fine-root biomass were negative and not reversible.(3)Fine-root growth and mortality occurred simultaneously and fine-root growth was dominant.The fine-root turnover of each water deficit treatment(2 kinds of estimation methods)were higher than CK treatment,and the fine-root biomass of K-F-F,F-F-K and K-F-K treatments were kept at high levels at full flowering or full bolling.?Conclusions? Late boll-setting was the sensitive period for fine-root biomass by water deficit.During this period,it is necessary to avoid water deficit operation.The selection of a reasonable water deficit drip irrigation strategy(K-F-F,F-F-K and K-F-K treatments in this study)can optimize the parameters of cotton fine-root and achieve high yield of cotton.2.Effect of water deficit at different periods on growth of above-ground and yield of drip irrigation cotton?Objectives? The experiment was to explore the effects of water deficit at different periods on growth of the ground,dry matter accumulation,yields and yield components of drip irrigation cotton.The proper mode of drip irrigation period of water deficit was studied in this paper.?Methods? By Single factor field experiment,the paper studied the variation characteristics of cotton plant height,LAI,dry matter quality,dry matter distribution ratio,yield and yield.?Results?(1)F-K-F,K-K-F,F-K-K and K-K-K water deficit treatments significantly reduced plant height and LAI;(2)The reproductive organs dry matter quality of K-F-F and F-F-K treatments compared with CK treatment were not significantly.The distributions of dry matter of reproductive organs at each water deficit treatments were higher than CK.Among all of them,K-F-K treatment had the highest dry matter distribution ratio,reaching 59.90%(2016)and 61.21%(2017);(3)F-K-F,K-K-F,F-K-K and K-K-K treatments had serious negative effects on the seed cotton yields and yield components.The seed cotton yield of K-F-F,F-F-K and K-F-K treatments achieved high levels.?Conclusions? Using suitable water deficit drip irrigation by K-F-F,F-F-K and K-F-K treatments saved irrigation water and realized high yield and stable yield of cotton.3.Effect of water deficit at different periods on WUE and NUE of drip irrigation cotton?Objectives? The experiment was to explore the effects of water deficit at different periods on water utilization efficiency and nitrogen utilization efficiency of drip irrigation cotton.?Methods? Field single factor random experiment was used to study the water absorption and utilization,nitrogen accumulation of cotton and nitrogen distribution characteristics of each organ.?Results?(1)K-F-F,F-F-K and K-F-K treatments in this experiment all obtained the WUEI and WUE higher than CK;(2)The characteristic of nitrogen absorption in each water deficit treatment was characterized by the tendency to distribute nitrogen to reproductive organs.The nutrient yield index of each water deficit treatment was higher than CK.The NUE of K-F-F,F-K-F,F-F-K and K-F-K were significantly higher than CK.?Conclusions? Combinated with the seed cotton yield,K-F-F,F-F-K and K-F-K were used to achieve high efficiency of water,nitrogen and high seed cotton yield.