Effects Of Organic Fertilization On Soil Environment And Growth Of Winter Wheat In Weibei Loess Plateau

A field experiment was conducted to determine the effects of organic fertilization on aridsoil environment and mechanism of crop growth under differently organic fertilizer supplies.In order to provide and perfect the basic theoretical to establish and the soil ameliorationtechniques system for arid areas of Weibei Loess plateau of Shaanxi. We studies the effects ofdifferent manure and wheat straw returning treatments, taking no organic fertilization as thecontrol, on soil moisture of each winter wheat growth periods, soil physical and chemicalproperties, crop yield and water use efficiency (WUE). The main results are as follows:1. The fertility treatment can better to improve the soil moisture conditions, play a goodeffect in moisture conservation.After the wheat harvest in2011, the average soil content andincrease soil water storage in0-200cm layer at harvesting stage significantly,(depth0-200cm)of manure and wheat straw returning treatments have the same change law in three maingrowth period of winter wheat (Jointing, Filling and Harvesting), compared with CK, theaverage soil content (depth0-120cm) of organic fertilizer treatments are all increase, and theamplitude was positively correlated with the application rate of manure and wheat straw.2. After the wheat harvest in2011, the soil bulk (depth0-60cm) of manure and wheatstraw returning treatments are lower than CK, the straw treatments decline1.3%～4.0%, andthe manure decline3.1%～6.0%, no significant between treatments. The soil bulk is reducedwith rate of fertilizer increase, and the manure is better than straw returning treatments. Thefertility treatment can better to improve the number and size of soil aggregates, therebyenhancing the structure level of mechanical stability and water stability aggregates structurelevel. The two aggregates in0-40cm soil layer, the straw returning and manure treatments allhigher than CK in soil aggregates content, MWD and GMD, and gradually increases withdepth, the variation trend is: S_H>S_M>S_L, M_H>M_M>M_L, and the straw returning is better than manure treatment.3. Fertility treatment differences in the impact of different soil nutrient content. Usingorganic fertilizers improved the amount of organic matter, and available nutrient(N,P and K).In the0-60cm layer, content of organic matter, and available nutrient(N,P and K) were higherthan that in the control, and the order is: S_H>S_M>S_L>CK, M_H>M_M>M_L>CK. For organicmatter in0-60cm layer, the straw returning treatments were5.8%～20.2%, the manuretreatments were4.6%～13.8%higher than CK, and the straw effect is slightly better thanmanure treatments; The content of available P in0-60cm only SHand M_Hwere16.91%and9.16%significantly higher than CK, and the manure is better; The straw and manuretreatments have the similar effect in of available N in0-60cm, were5.9%～28.0%and6.8%～31.1%higher than CK. The influence of organic fertility treatment effect on soil totalnutrients (TN, TP, TK) is not marked, only0-20cm is obvious, compared with CK, theincrease followed by3.9%～33.3%,5.9%～28.0%and6.6%～20.4%, and with thedeepening of soil layer, the increase is gradually reduce.4. The fertility treatment can better to improve the soil Urease, Invertase andPhosphatase of0-60cm soil layer. Using organic fertilizers were more than that in the control,with the deepening of soil layer,the increase is gradually reduce,and the enzyme activityincreased with the increase in the amount of straw or manure.For the Phosphatase in0-60cm,the straw returning treatments were5.8%～20.2%and the manure treatments were4.6%～13.8%higher than CK; For the Urease and Invertase in0-60cm, the straw returning andmanure treatments have the similar effect, and the Urease of each treatments4.6%～13.8%higher than CK, and the Invertase increased34.4%～98.4%; The two kind of fertilitytreatment were slightly higher than CK of soil Catalase in0-60cm soil layer, but notsignificantly. The Catalase activity have positive correlation with the amount of strawreturning or manure application, but little change with soil depth, The fertility treatment cannot better to improve the soil Catalase activity.5. Organic fertilizer can improve the flag leaf area of winter wheat significantly,the orderof straw returning treatments at heading stage and filling stage is SH>SM>SL>CK, comparedwith the CK, all straw returning treatments have an average increase of15.7%, the order ofmanure treatments is M_M>M_H>M_L>CK, all manure treatments are15.3%higher than the CK. 6. Not only the growth and dry matter accumulation of winter wheat under continuousapplication of organic fertilizer can promote significantly, but the yield also had a significantincrease. After2011harvest, for the yield of winter wheat, the order of different fertilizerapplication treatments is: S_H>S_M>S_L, M_M>M_H>M_L, S_H, S_M and S_H, SMwere significantlyhigher than CK, the increase followed by25.3%,16.9%(P<0.05),20.0%,21.8%(P<0.05).WUEYhas the similar law with yield, SH, SMand SH, SMwere significantly higher than CK,the increase followed by30.5%,19.7%,27.7%and24.6%(P<0.05).