Effects Of Water-fertilizer Coupling On Field Cotton Under Fertigation

This experiment carried in ShiHezi, XinJiang academy of land reclamation in2012-4-11,with cotton as the research object, through field experiments set three water levels （W₁100ET0, W₂80%ET0and W₃60%ET0） and three fertilizer levels （N, P₂O₅, K₂O）（F₁350,140,70; F₂250,100,50; F₃150,60,30）, a total of nine, studied under the condition of dripfertilization fertilizer coupling on cotton growth, yield, water use efficiency and soil moisturechange rule, soil NO3-Ntransport rule and effect on nutrient absorption and utilization,madethe following main conclusions:（1）Different irrigation water and fertilizer on plant height were presented significantinfluence, With the increase of irrigation water and fertilizer,the cotton plant height differencetreatment is increased significantly.The plant height under the same fertilization level reachedmaximum at W₁, W₃, and under the same water level, F₁influence on plant height is limited,and there was no significant difference of F₁and F₂. Stem diameter in the early growth,different fertilizer application and irrigation water on the no significant difference. Along withthe growth period, the same fertilizer rate under different water level has significant differenceto the stem diameter, the same water level under different fertilizer rate also producesignificant differences on stem diameter, water deficit caused serious cotton stalk thicknesswhen the W₃small cotton stem diameter and minimum in W₃levels under differentfertilization rate had no significant effect on stem diameter. But in W₁high levels of fertilizerapplication led to the decrease of the cotton stalk growth decreased or even F₁> F₂> F₃. Withgrowth period, under the same fertilizer level of different irrigation water on cotton leaf areaindex reached extremely significant level, under the same water level, different fertilizer ratewater cotton leaf area index reached extremely significant level, the fertilizer effect is reachedextremely significant level under the same water level F₁> F₂> F₃, under the same fertilizerlevel W₁> W₂> W₃. High and low fertilization will harmful to leaf area index,comprehensive show W₁F₂combination of sewage sludge on plant height, stem diameter, leafarea index growth is most favorable.（2） Different irrigation water and fertilizer at the early stage of the family had nosignificant influence on dry matter accumulation.With the growth period different quantity of irrigation water and fertilizer had significant influence on dry matter accumulation. Under thesame water level, F₁reaches maximum value,the F₃minimum.Under the same fertilizer level,W₁, W₃reaches minimum; Irrigation water play a leading role in dry matter accumulationprocess. Fertilizer effect has significant effects on dry matter, comprehensive analysis,reached the maximum when W₁F₂amount of dry matter accumulation. Different irrigationand fertilization on seed cotton yield was extremely significant level.With the increase offertilizer rate and irrigation water, The seed cotton yield increased.The W₃level underdifferent fertilizer rate had no effect on seed cotton yield, fertilization rate is too high to causea decline in seed cotton yield. Coordination role water has significant effects on yield bestwhen W₁F₂. Law of lint yield and seed cotton yield is similar. Different irrigation water has asignificant effect on irrigation water use efficiency.With irrigation water increase, irrigationwater use efficiency decline. Production has a linear relation with the amount of dry matteraccumulation, maximum of dry matter, yield the highest. Yield and dry matter accumulationamount and irrigation water use efficiency, a quadratic parabola relationship, with the increaseof irrigation water efficiency, yield and dry matter accumulation amount after the firstincrease.（3）Different irrigation and fertilizer effect on soil water in the membrane, membrane,membrane between the distribution.In the cotton maternity period, soil moisture content in thecotton growth period reached maximum during the blooming period, with the development ofgrowth period, soil moisture content is reduced gradually. W₁F₂processing relatively evendistribution of soil moisture content which film> in the film edge> bare land is moreadvantageous to crops to absorb moisture. In vertical direction under the same fertilizer rate,moisture content in membrane increased with the increase of irrigation water also showed atrend of increase and soil moisture content soil moisture migration downward; Differentirrigation moisture content gradually reduce with the increase of soil depth. W₃processingdeep seepage scope of small but wet little influence scope of crop root growth, in turn, affectcrop growth and development, W₂processing depth of soil moisture content are mainlyconcentrated in cotton taproot60cm, the crop water and nutrient utilization is higher. W₁processing deep seepage but moist range larger increases the crop root growth space is moreconducive to crop growth and nutrition.（4）Different irrigation and fertilizer effect on content of soil NO3-Nand migrationinmembrane, membrane, membrane.Under the same fertilizer rate, with the increase ofirrigation water,soil NO3-N downward migration apparent.W₃F₃processing soil NO3-N lessdownward migration of a large number of accumulation in the soil surface; W₁F₃appear lessfertilizer Lin makes the content of soil NO3-N loss; W₁F₂better coordination, water nitrate are mainly distributed in60-80cm in low content of soil no3--n Lin lost less absorbed by cropsgood use; W₁F₁fertilizer elim serious loss results in the decrease of fertilizer utilization.Horizontally under the same irrigation water W₁, W₁F₃treatment migration faster, bare landaccumulated nitrate content more, the content of film and film edge closer, W₁F₂processingof even distribution of soil NO3–N. W₁F₁processing membrane, membrane and bare land inthe nitrate nitrogen content were higher than the other two increased leaching amount andprocessing. With the increase of irrigation water level under the same fertilization levelmigration accelerated, W₂deal with nitrate nitrogen content in the membrane, membrane andbare land are lower than the other two side handle, with soil depth increase content decreasedsignificantly high utilization rate of fertilizer. W₁deal with vertical and horizontal migrationapparent bare land> film edge> film, bare land fertilizer Lynn loss is bigger.（5）Different irrigation water and fertilizer has remarkable effect on nutrient uptake incotton.Under the same water level, with the increase of fertilizer rate, different organs showeda trend of increase for the absorption of nutrients. With the development of growth period,nitrogen content in the cotton boll is higher, less content of nitrogen in stems, nitrogen contentof different organs in different fertilization treatment F₂than F₁, F₃. Different fertilizertreatment, high phosphorus content of cotton boll, the stem leaves smaller; F₂treatment on theabsorption of phosphorus is advantageous; The potassium content in different organsvolatility is larger, leaf potassium content of the highest, followed by cotton boll and thestem,F₂higher than that of F₁, F₃. Under the same water level with the increase of growthperiod in advance and fertilizer N, P, K accumulation were presents increasing trend. F₁’slargest nitrogen accumulation; Phosphorus and potassium accumulation of F₂handle peak; F₃to handle all the nutrient accumulation is minimal. With the increase of fertilizer,nitrogenutilization efficiency is lower, the F₃treament is the highestnitrogen use efficiency, F₁is lowest;the F₂treament is the highest phosphate use efficiency, F₁is lowest; the F₂treament is the highestpotash fertilizer use efficiency, F₁is lowest F₂>F₃>F₁.Composite can be seen the effect of differentfertilizer treatment on yield W₁F₂yield is higher, the demand for nitrogen, phosphorus andpotassium nutrient use efficiency is higher, the greater the fertilizer loss is small, the couplingeffect of water to achieve the best effect, However, Excessive fertilizer application results inthe decrease of cotton on the absorption of nutrients utilization and cause waste of thefertilizer.Low fertilizer can improve nutrient use efficiency but can’t meet the crop nutrientdemand results in the decrease of production.