Effect Of Rape Green Manure On Soil Organic Carbon And Enzyme Activity In Saline Soil

Xinjiang is the region with the most types of saline-alkali soil distribution,the most extensive distribution area,and the most serious salt accumulation.The soil salinization in Xinjiang's irrigation areas has reached 37.72%,which seriously hinders the sustainable development of Xinjiang's oasis agriculture.Soil salinization will affect the supply of soil nutrients,resulting in poor growth and development of crops,lower yields and lower quality.In order to reduce the expansion of saline-alkali soil area in Xinjiang,it is of great significance to explore effective and reliable saline-alkali improvement measures to alleviate the problem of soil salinization.Therefore,based on the moderate saline-alkali soils in northern Xinjiang,this study set different treatments for returning rapeseed green manure to the field:no rapeseed green manure return?CK?,rape green manure return 1 year?T1?,rape green manure return 2 years?T2?,to study the effects of different years of rapeseed green manure return on saline-alkali soil physicochemical properties,organic carbon components,and enzyme activity,to reveal the effect of rapeseed green manure return on saline-alkali soil alkali reduction and salt removal,which is an arid region in Xinjiang oasis Saline-alkali soil improvement provides theoretical support.The main results are as follows:Returning rapeseed green manure to the field can significantly reduce the pH and EC values??in the soil of cotton fields 0-20 cm,20-40 cm,and 40-60 cm soil layers.With the increase in the years of rapeseed green manure return,the pH and EC values The more obvious the decrease is;the return of rapeseed green manure to the field all increased the content of organic matter,total nitrogen,total phosphorus,and total potassium in the soil layers of 0-20 cm,20-40 cm,and 40-60 cm,and the organic matter,total nitrogen,total phosphorus,total Potassium content decreases with increasing soil depth;the content of basic cations and basic anions in each soil layer of rapeseed green manure returned to the field for 1 and 2 years is significantly reduced,and the trend of ion changes in saline-alkali soils is Ca²⁺,K⁺,Mg²⁺,SO₄^2-accumulated in the surface soil,Na⁺,Cl^-,CO₃^2-,HCO₃^-to accumulate in the deep soil,rapeseed green manure returned to the field can significantly reduce the soluble Na⁺,Ca²⁺,Mg²⁺,K⁺in the saline-alkali soil of 0-60 cm plow layer And the ion content of CO₃^2-,HCO₃^-,Cl^-,SO₄^2-,and the effect is more obvious with the increase of the years of returning green manure.Returning rapeseed green manure to the field can increase the content of organic carbon in saline-alkali soil.Compared with the return of rapeseed green manure,the content of SOC,SLOC,SDOC and SMBC in the 0-20 cm,20-40 cm and 40-60 cm soil layers of cotton fields after the return of rapeseed green manure returned to the field.Increasing and increasing,and with the increase of the depth of saline-alkali soils,the soil carbon component content tends to decrease.The comprehensive effect of the return of rapeseed green manure to the soil organic carbon component content is:T2>T1>CK.The content of SOC,SLOC,SDOC,and SMBC in the soil of rapeseed green manure return was significantly higher than that of rapeseed green manure return.Returning rapeseed green manure to the field can promote the activity of saline-alkali soil enzymes.The activities of invertase,urease,alkaline phosphatase and catalase in saline-alkali soil showed a significant improvement effect after returning rapeseed green manure to the field,and the improvement effect of returning rapeseed green manure to the field for 2 years was the best The effect of improving the enzyme activity of saline soil is:T2>T1>CK.The activity of saline-alkali soil enzymes is obviously affected by soil depth.With the increase of soil depth,the activity of catalase increases,and the activities of invertase,urease,and alkaline phosphatase show a downward trend.