| Reasonable irrigation and fertilization is the foundation of high yield of wheat.In dryland rainfed agricultural areas,the insufficient rainfall,dislocation of water supply and demand,resulted in lower wheat water use efficiency and limited grain yield.Fertilizer,especially the organic fertilizer application regulated the crop water utilization remarkably.In rain-fed area,regulting crop water use by reasonable fertilizer application,and promoting fertilizer utilization by water management,as well as optimizing root water and nutrient use coordinately,were the basical methods to increase crop yield.In order toclarify the effects of supplemental irrigation and organic fertilizer on yield of spring wheat whichmulched by plastic-soil,a field experiment carried out from 2015 to 2016 in Dingxi experimental station of Gansu Academy of Agricultural Sciences.The three treatments involved in the filed experiment,supplemental irrigation with plastic-soil mulching(PMSI),high amountorganic fertilizerapplication withplastic-soil mulching(PMO),plastic-soil mulching(PMS)as the control.the 0-300 cm soil moisture,soil temperature in 0-25 cm soil layer,crop leaf SPAD,canopy temperature,leaf area index,biomass,yield and yield components were investigated,to determine the effects of supplemental irrigation and organic fertilizer application on water consumption,yield and water use efficiency of spring wheat which mulched by plastic-soil.This work was helpful to understand the mechanism of water and nutrient utilization of spring wheat cultured by plastic-soil mulch and bunching,and provide theoretical basis for exploring the higher spring wheat yield cultural technology in semiarid area in north-west region.The main results were as belows:1.PMSI treatment can significantly increase the water and soil water consumption of spring wheat in the whole growth period,PMO treatment can increase the water consumption of spring wheat from sowing to flowering,reduced soil water storage.From jointing to heading,heading to flowering,flowering to filling,filling to mature,the water consumption of PMSI significantly increased by 18.2%,22.8%,14.6%,17.2%,decreased by 11.7%,14.9%,8.3%,9.9% in PMO treatment,ascompared with PMS treatment.2.During the whole growth period,PMSI and PMO treated each growth period of 0-25 cm,and the average ground temperature decreased by 0.7 ?and 0.6 ? over the PMS treatment.PMSI treatment significantly reduced soil temperature at the 0 cm,10 cm and 15 cm soil depth by 0.7 ?,1.6 ?,1 ?,PMO treatment significantly reduced soil temperature at the 10 cm,20 cm and 25 cm soil depth by 0.9 ?,1.4 ?,respectively;PMO increased soil temperatures at 0cm,5cmand 10 cm depthin earlyspring wheat growth period.PMO and PMSI alleviatedthe fluctuation of soil temperature in wheat later growth period,this would be relieved the adverse effects of high soil temperature on wheat reproduction.Conquestly,PMSI and PMO decreased soil temperature during the late growing period of wheat,this was help for decreasing the damage to root development.3.Both PMSI and PMO treatments can increase chlorophyll content of Spring Wheat.The chlorophyll content of PMSI increased by 3.6%,3.7%,2.8%at the jointing,flowering and maturity stagerespectively,it was only increased by 2.0% in PMO in flowering stage,as compared with PMS.PMSI significantly increased average leaf area(LAI)index by 15%,and PMO increased LAI by 4%,as compared with the PMS.The LAI of PMSI and PMO in jointing and filling stage were significantly increased by 20.5%,16.9% and 7.4%,8.6%,respectively,as compared with PMS,PMSI treatment can reduce canopy temperature of spring wheat in the whole growth period,and average decrease by 0.9 ? compared with PMS treatment.The cooling effect in the mature stage is the most significant,which decreases by 1.6 ?;For PMO,the canopy temperaturewas higher in 2015,but lower than PMS treatment in 2016.4.The PMSI and PMO treatment increased the aboveground biomass through whole growth period of spring wheat.The biomass of spring wheat in PMSI and PMO increased by 9.1% and 1.8% recpectively,as compared with PMS treatment.The biomass of spring wheat in PMSI increased significantly with the advancement of the growth period.PMSI treatment can significantly improve the wheat ear weight and grain dry weight,respectively,compared with the PMS treatment increased by 15% and 20.3%;PMO treatment can significantly increase in wet years of spring wheat panicle weight and grain dry weight,the precipitation in 2015 is relatively more,increased by 9.7% and 9.2% respectively,in dry years,the effect is not obvious.5.Thewater consumption of spring wheat in PMSI and PMO significantly increased by 21.8% and 8.2%,as well as yield increased by 13.9% and 12.7%,respectively,as compared with PMS.The annual rainfall in 2015 were higher than that in 2016 by 67.7mm,PMSI and PMO treatment increased the water use efficiency by 17.9% and 11.4% in 2015,while it were decreased by 42.4% and 8.4% in2016 respectively,as compared with PMS.These results indicated that PMSI and PMO increased WUE of spring wheat in normal rainfall year.However,based on the sufficient soil water and nutrientcontent,the water consumption of spring wheat were promoted,this may aggravated the drought stress in wheat later growth period,resulted in the increased yield and decreased WUE.Accordingly,PMSI and PMO treatment regulated the sbsorbing of soil water and nutrient by spring wheat root,increased water consumption from jointing to maturity stage,improved the leaf area index and biomass,resulted in the increased grain yield.Therefore,it is important toenhance the yield of spring wheatby supplemental irrigation and organic fertilizer application. |
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