Effects Of Tillage Method And Organic Fertilizer On Change And Use Of Soil Water,Carbon And Nitrogen

Frequent seasonal drought occurs in the fluvial soil area of eastern Henan Province,and the long-term unreasonable tillage method results in the decrease of soil water storage and moisture retention capacity,the decrease of soil fertility,and low water and fertilizer utilization efficiency.Reasonable tillage method and application of organic fertilizer can improve soil moisture retention,enhance soil carbon and nitrogen retention,and promote the absorption and utilization of water,carbon and nitrogen by crops..Therefore,it is of great significance for agricultural production to explore the effects of different tillage methods and organic fertilizer treatment on soil water carbon and nitrogen change and utilization.This study is based on the long-term trial,soil bulk density,soil moisture,soil carbon and nitrogen content and soil enzyme activity were measured in the key growth stages of wheat,and the absorption and utilization characteristics of water,carbon and nitrogen,as well as the growth index and yield of wheat were analyzed.The effects of different tillage methods and organic fertilizer on the change and utilization of soil water,carbon and nitrogen were systematically revealed,and the increasing yield mechanism of wheat under different treatments was further clarified,which provided theoretical basis and scientific support for carbon fixation and fertilizer cultivation,efficient utilization of water and nitrogen,and stable and increasing crop yield.The main conclusions are as follows:1.Reasonable farming method and application of organic fertilizer could reduce soil capacity,increase soil water and improve water utilization efficiency.Compared to other treatments,subsoiling tillage + organic fertilizer(STF)and straw mulching + organic fertilizer(SMF)treatment could significantly reduce soil bulk density,increase field water capacity and soil water storage in 0-100 cm soil layer.In addition,STF treatment was also beneficial to increase soil water content in 0-100 cm soil layer at wintering,anthesis and filling stages and 0-40 cm each soil layer at jointing and maturity stages.SMF treatment could significantly increase the soil water content in 60-100 soil layer at jointing and maturity stages.Moreover,STF and SMF also significantly reduced the water consumption during the growth period of wheat,and the water use efficiency by 57.80% and 47.79%,respectively,compared with conventional tillage(CT).2.Reasonable farming methods and application of organic fertilizer could improve the activity of soil enzymes and promote the storage and transformation of soil carbon and nitrogen..STF could effectively improve the activity of sucrase(except anthesis stage)and urease,and significantly increase the contents of organic carbon,total nitrogen,microbial carbon.Furthermore,STF significantly increased microbial nitrogen in the ploughing layer before anthesis stage.SMF treatment significantly improved the activity of protease in the ploughing layer during wheat growth period,the activity of cellulase and the content of nitrate nitrogen in the ploughing layer soil at filling and maturity stages.In addition,SMF significantly increased the content of microbial biomass nitrogen in the ploughing layer after jointing stage.Straw mulching(SM)significantly increased the activity of cellulase in the ploughing layer of wheat during wintering and flowering stages,and conventional tillage + organic fertilizer(CTF)significantly increased the content of ammonium nitrogen in surface soil at different growth stages of wheat(except anthesis stage).From correlation analysis among soil enzyme activities,microbial biomass,soil organic carbon and nitrogen showed that: the soil enzyme activity,microbial quantity and organic carbon and nitrogen content promoted each other.3.To carbon and nitrogen absorption and utilization of plant,STF could significantly increase carbon accumulation at jointing,filling,and maturity stages of wheat and nitrogen accumulation after jointing stage of wheat,and significantly improve the partial productivity and nitrogen use efficiency.SMF could significantly increase carbon accumulation of wheat plants at anthesis stage and nitrogen accumulation of wheat plants before anthesis,as well as nitrogen dry matter production efficiency and nitrogen harvest index.4.Compared with conventional tillage,STF treatment could significantly increase plant height from jointing to maturity stage and leaf area and relative chlorophyll content(Spad value)of wheat at jointing and filling stages,and significantly increase biomass after jointing stage,reduce aborted spikelet,increase spike grain number and spike number.SMF significantly increased leaf area,Spad value of wheat at flowering stage,and biomass before anthesis stage.Moreover,SMF promoted the increase of spike length and spikelet number of wheat.Compared with CT treatment,the yield of wheat under STF and SMF was increased significantly by35.58% and 23.59%,respectively.The correlation analysis among soil organic carbon,nitrogen,water storage and yield,water use efficiency showed that: the increase of carbon,nitrogen contents in the ploughing layer and 0-100 cm water content could promote the increase of yield and water use efficiency.In conclusion,STF and SMF could significantly reduce the soil bulk density of surface layer,increase the 0-100 cm soil water storage,improve the water and nitrogen utilization efficiency,the contents of organic carbon,total nitrogen,microbial biomass carbon and nitrogen and soil enzyme activities in the ploughing layer,thus promoting the growth and increased yield of wheat.