Study On Soil Conditioners On Soil Physical And Chemical Properties And Crop Growth Under Winter Wheat And Summer Maize Rotation

The farmland soil in northern China under summer maize-winter wheat rotation cropping had showed many problems such as poor texture,poor structure,salinization and acidification.This paper was based on the farmland in Wuqing District,Tianjin,and seted up field positioning experiments for different conditioning agents.Through the research of soil physical,chemical properties,nitrogen and phosphorus transport,crop growth and nutrient absorption,etc.,in order to achieve the goal of improve crop growth environment,increase crop yield and promote planting.The research results are as follows:The biochar application treatment improved the soil bulk density,and the soil bulk density decreased from 1.39 g/cm3 at the beginning of the test to 1.20 g/cm3 after the test.The content of soil aggregate structure in biochar,biochar + alum treatments increased by 5.36% and 5.85%,respectively.The water holding capacity of each conditioning agent was enhanced,and the biochar + alum treatment and biochar treatment were increased by 1.58% and 0.33%,respectively,compared with the blank treatment.The effect of biochar treatment on soil cation exchange was most obvious,reaching 25.83 cmol(+)/kg at the time of the third season winter wheat harvest.After three plantings the surface soil organic carbon content of biochar,biochar and alum was 13.29g/kg and 14.24g/kg,and the soil C/N was 9.59 and 10.59.The treatment of humic acid,biochar and silicic calcium materials had a better effect on improving soil nitrate nitrogen,available phosphorus and water soluble phosphorus.Biochar + alum treatment had a better effect on improving soil phosphatase and urease activity.On the whole,biochar,biochar + alum treatment was better than soil physical,chemical and enzymatic properties.Biochar,siliceous calcium materials,biochar + alum treatment can promote crop growth.The treatment of biochar and alum was beneficial to the chlorophyll synthesis of crops.The treatment of biochar and biochar alum increased the grain yield most.The first summer maize reached 11.34×103 kg/hm2 and 10.61×103 kg/hm2,the second winter wheat was 9.20×103 kg/hm2 and 10.28×103 kg/hm2,and the third summer maize was 7.21×103 kg/hm2 and7.20×103 kg/hm2.Biochar + alum treatment was beneficial to the increase of biomass and the absorption of itrogen,phosphorus and potassium.According to the comprehensive data analysis of triterpenoids,biochar and biochar + alum treatment had better effects on crop growth and nutrient absorption.In terms of environmental effects and economic benefits of nitrogen and phosphorus transport,biochar,biochar + alum treatment can reduce nitrate-nitrogen migration.Humic acid,biochar,alum,silicon calcium material,biochar + alum treatment had better effect on reducing effective phosphorus and water-soluble phosphorus transport.The total output benefit of alum and silicon-calcium materials treated by three crops was good,and biochar,biochar + alum treatment had a good trend of increasing benefit.From the perspective of economic benefits,after treatment with three crops,humic acid and silicic calcium materials were better treated,the input-output benefits were 28,200 yuan/hm2 and 29,100 yuan/hm2 respectively.In the long run,biochar,biochar + alum treatment may exceed the previous two treatments,and further research is needed for long-term positioning experiments.Through one and a half years' positioning test of soil conditioner,biochar,biochar + alum treatment had a good effect on soil physical and chemical properties and enzyme traits,crop growth and nutrient absorption,nitrogen and phosphorus transport environmental effects,and economic benefits.