Study The Effects Of Several Soil Amendments On Acid Paddy Soil And Red Soil

Abstract:Through combination of pot and field experiments, acid paddy soil and acidic red soil were selected to study the effects of different modifiers on the physical and chemical properties of the soil,agro-nomic traits and yield of crops,revealing the change law of the variation of acidic rice soil and dry soil physical and chemical properties,and explored the mechanism of different soil amendments.The conclusions are as follows:(1) Experiment results for different soil modifiers in improving acidic paddy soil:Quicklime and modifier M had a good adjustment for physical and chemical properties of acid paddy soil.Quick lime and modifier M improved soil pH significantly compared with the CK;modifier M improved nitrogen contents significantly;quicklime and modifier M improved exchangeable Ca,Mg,total exchangeable bases and base saturation significantly;quicklime and modifier M increased the total amount of>0.25mm Soil total aggregate and water-resistant aggregate significantly in a certain period,reduced aggregate destruction and improved aggregate stability significantly.Applying modifiers to soil could reduce the amount of exchangeable aluminum,alleviated the harm of aluminum toxicity in acidic soils,in a certain period could also reduce the total cadmium content,their contents were significant negative correlation with soil pH.In this study,soil pH impacted on soil physical and chemical factors greatly,and had a significant or a very significant positive correlation with phosphorus,exchangeable potassium,exchangeable sodium,exchangeable calcium,total exchangeable bases,base saturation and Ca/Mg.Soil physical and chemical factors had a big influence on the rice yield, through the path analysis, we knew the order of the size(absolute value) of the direct effect on early rice yield were:cation exchange capacity>Ca/Mg>pH>total lead>P>Al>available N;the order of the size(absolute value) of the direct effect on late rice yield were:pH>soil saturation>K>Ca/Mg>organic matter>exchangeable Na. (2) Experiment results for different soil modifiers in improving acidic red soil:Quicklime,dolomite,calcium magnesium phosphate and improvers M had a good regulation on the physicochemical properties of acidic red soil.All improvers increased soil pH significantly compared with the control;and all improvers improved exchangeable Ca,Mg,and the total amount of exchangeable base significantly;quicklime,dolomite powder and improvers M improved the soluble salt contents,base saturation significantly.In the study,soil pH impacted on soil physical and chemical factors greatly,had a significant or very significant positive correlation with phosphorus,exchangeable Ca,Mg,total exchangeable bases,base saturation and soluble salt contents.All improvers increased the soybean yields significantly.Soil physical and chemical factors had a great impact on soybean yield,through path analysis,we knew the order of the size(absolute value) of the direct effect on soybean yields were:soil saturation>soluble salt content>exchangeable Mn>Ca/Mg>cation exchange capacity.