Effects Of Different Utilization Patterns On Soil Organic Carbon Components And Soil Quality Evolution After Terracing

In order to effectively increase the amount of cultivated land and ensure food security,the implementation of the slope-reformed land improvement project is an effective way to improve the quantity and quality of cultivated land.However,the implementation of the terracing project seriously disturbs the soil environment and ecosystem,and strongly disturbs the soil.Both organic carbon composition and soil quality will affect the soil carbon pool and soil quality after the slope is changed.The soil organic carbon composition and soil quality change with time under different utilization modes.The dynamic repair features are critical to improving and protecting the quality of agricultural land.In this paper,the soil used as cultivated land and garden land in the typical slope improvement project of Taihang Mountain low hilly area is taken as the research object,and the dynamic characteristics of soil organic carbon composition in different soil depths in different years of slope change ladder are compared.Soil quality evaluation was carried out by changing the soil of the ladder,revealing the changes of soil carbon pool and soil quality after the change of the slope and the change of utilization pattern.The main research results are as follows:（1）Soil organic carbon and its components（soil organic carbon TOC,soluble organic carbon DOC,readily oxidizable organic carbon ROC,microbial biomass carbon MBC,microbial entropy in the surface layer of cultivated land and orchard after slope conversion qSMBC,carbon emissions CO₂-C）were the lowest values of the years after the slope was changed,and the average values were 35.2%,20.0%,35.1%,61.3%,41.2%and 28.9%,respectively.The TOC,DOC,ROC,MBC,qSMBC,and CO₂-C of the cultivated land and garden land 8a after the slope change to the terracing can be restored to the level before the slope is changed.However,compared with the slope change before the ladder,the 8a cultivated land after the slope change terraced no significant difference,and the orchard increased significantly by 21.02%,27.57%,26.79%,15.94%and 11.11%before the slope was changed.The organic carbon and its components in the 20a cultivated land and orchard showed a downward trend after the terraced was changed.（2）The organic carbon storage（SOCs）,carbon storage index（CPI）,carbon storage activity index（LI）and carbon pool management index（CMI）of cultivated land and garden in different years after slope conversion are all 8a>slope change Before the ladder>20a>2a,the 2a cultivated land and orchard after the slope change to the terraced are the lowest values of the study years,which are significantly lower than the average before the slope change to 46.29%,29.75%,30.00% and 24.00%;Compared with the previous one,there was no significant difference in the 8a cultivated land after the slope was changed,and the orchard was significantly higher than the slope before the ladder was changed.The orchard showed higher soil carbon pool quality.However,both the slope change terracing 20a and the 8a have a downward trend compared with the cultivated land and the orchard.（3）Analysis of soil TOC,ROC and DOC in different soil depths after slope conversion to slopes,and it is concluded that the vertical distribution of cultivated land and orchard soil in different years after the slope is changed to terraced with the depth of the soil layer.And the characteristics of the change are reduced.The trends of soil TOC,ROC and DOC in the soils of 10～20 cm,20～40cm and 10～20 cm,20～40cm and 40～60cm in different fields after the slope change to the terracing are basically consistent with the surface layer.（4）Through the establishment of the slope-to-step soil quality evaluation system,the soil quality of cultivated land and orchards with different years is 8a>20a>2a,which is the lowest value after the slope is changed to 2a.The reduction of 52.00% and 38.44% was improved and restored after the slope was changed to 8a,but the slopes and terraces of 20a had a downward trend;while the slopes changed to different utilization modes after the ladder,the gardens showed higher soil quality.The soil quality scores of the farmland were28.25%,58.03%,and 40.24%higher than that of the cultivated land,and the utilization of the slopes to improve the soil quality could be better.The evolution characteristics of soil organic carbon and its components after the typical slope change in the hilly area of Taihang Mountain,and the evaluation of the soil quality of the slope changing terracing,revealing that the slope to terracing utilization as a field has higher potential for soil organic carbon accumulation.And it is more significant for improving and protecting soil quality.However,the use of different methods in the long-term loss of carbon stocks and soil quality decline,so in the later stage should pay more attention to management.This will provide a reference for the rational use of land after slopes,the carbon sequestration of agricultural land ecosystems,and the protection and improvement of land quality for sustainable development.