Effects Of Deep Buried Straw And Leaching Treatment On Soda-saline-alkali Soil Improvement In Momoge Region

With the decrease of cultivated land area,the problem of soil salinization exists widely,and seriously endangers the usable area of cultivated land.Using reasonable and effective remediation technology to improve soil water supply and fertilizer capacity is an important scientific problem to be solved urgently.The mass burning of straw has brought a lot of harm to China.The large-scale haze weather in north China is closely related to straw burning.Therefore,controlling straw burning and reasonably solving straw use is one of the important issues to be solved in the process of realizing sustainable agricultural development in China.In this study,the typical soda saline-alkali soil in Momoge Nature Reserve of Jilin Province was taken as the research object.The method of deep burying straw was used to improve the environmental temperature of straw fermentation,and the soil salinization was improved by superposition leaching treatment.Furthermore,the changes of soil nutrient content,cation exchange capacity and enzyme activity under different methods were investigated in order to provide a low-cost,efficient and lasting way for sodic saline-alkali soil improvement and application in Songnen Plain.The results show that:(1)The average soil moisture content in the study area was 16.9%.The average pH value was 9.448,and all of them were in alkaline state.The soil organic carbon,ammonium nitrogen,nitrate nitrogen and available phosphorus were all at low levels,and the contents of each nutrient decreased with the increase of the vertical depth of the soil profile.The soil exchangeable sodium ion exchange capacity and exchangeable calcium ion exchange capacity were high,and the exchangeable magnesium ion and exchangeable potassium content were relatively low.The activities of soil cellulase increased with increasing profile depth,while the activities of sucrase and urease decreased with increasing profile depth.(2)Soil moisture content increased after deep buried straw treatment(S);The pH value and electrical conductivity of soil decreased significantly.The content of organic carbon,ammonium nitrogen,soil nitrate nitrogen and available phosphorus all increased.Exchangeable sodium ions decreased significantly,exchangeable magnesium ions,potassium ions and calcium ions increased to some extent.The activities of soil cellulase,sucrase and urease increased.Soil nutrient content and enzyme activity increased more near the straw layer.(3)Soil moisture content increased after deep buried straw superposition leaching treatment(SW);pH value decreased significantly;Electrical conductivity is significantly reduced.The content of organic carbon,ammonium nitrogen,nitrate nitrogen and available phosphorus increased to a certain extent.Exchangeable sodium ions,magnesium ions,potassium ions and calcium ions all showed a significant decreasing trend.The activities of cellulase,sucrase and urease in soil increased significantly.(4)Correlation analysis showed that there were a lot of significant relationships among soil indices.Among them,soil pH and conductivity were significantly negatively correlated with nitrate nitrogen,ammonium nitrogen,cellulase,and sucrase(P<0.01),significantly negatively correlated with urease(P<0.05),and significantly negatively correlated with Na⁺,Mg²⁺,K⁺.There was a very significant positive correlation between the exchange volume(P<0.01).There were extremely significant positive correlations between soil organic carbon,ammonium nitrogen,nitrate nitrogen and cellulase,sucrase and urease(P<0.01).There was a significant negative correlation between soil water content and four kinds of cation exchange capacity(P<0.01).The results of principal component analysis showed that the deep-buried straw superimposed leaching treatment had the best improvement effect on saline-alkali soil.