Effects Of Straw And Biochar On Soil Organic Carbon Pool Management Index And Soil Nutrients

Black soil is an important type of soil in northeast China, also is one of the major grain production bases in China.But in recent years,the unreasonable agricultural management measure results in the decrease of soil organic matter content,the soil degradation phenomenon is serious.Straw returned to soil as a conservation tillage measures plays an important role on soil improvement.But today’s the environmental problem is growing,straw returned to soil causes a large amount of CO₂ will further aggravate the environmental burden.Straw biochar arises at the historic moment.With its good environmental effect and ecological effect become a research hot spot.Study the effect of the contrast of straw and straw biochar on soil,and provided the scientific basis for degradation of black soil improvement.Based on soil as the research object,this paper carries out two indoor experiments.The first study with the constant temperature box under constant temperature and humidity,investigating the effects of straw and biochar are added to two different organic carbon black soil on the content of soil organic carbon and carbon pool management index.The next study with Plastic bucket under constant humidity,investigateing effects of different intake of straw and biochar on carbon pool management index and the influence of soil nutrient.Specific research results are as follows:The CO₂ emission in low organic carbon soil higher than in high organic carbon soil,Biochar was applied had no significant effects of the CO₂ emission during the two black soil;Straw can increase soil organic carbon more in high organic carbon soil. Biochar can significantly improve the two black soil organic carbon and no obvious difference was found between the increase.Straw can increase soil active organic carbon of two black soil and the increase was the same basically.Mixed application can increase the soil microbial biomass carbon best,and the increase is higher in high organic carbon soil.In addition,straw improved soil carbon pool management index,and biochar lower it.And the the change is more severe in low organic soil.The straw with the increasing of application rate of intake, the release of soil CO₂ is also increasing gradually.Quality ratio is 1%,3% and 5% of the straw is 3.40,5.83,7.51 times than control treatments.Straw biochar can also improve CO₂ emission of soil,The corresponding quality ratio of straw biochar,the CO₂ emission of soil increased by 4.4%,6.1% and 6.1%,is far less than the straw.Straw biochar to make the improvement of soil organic matter content is better than the straw.Straw more effectively improve the activity organic carbon,microbial biomass carbon andcarbon pool management index.The straw and straw biochar all can increase the content of humic acid,HA and FA. And the straw make the better effect,at the same time,the FA increasing effect more apparent than HA.Straw and straw biochar can improve soil nutrient content,and the straw biochar for improve soil n,p,k nutrient index effect is better than that of straw.Straw can improve soil aggregate content,but the straw biochar about soil aggregate and micro aggregate content change is not obvious.