Effects of tillage practices on soil CO2 emissions in red soil sloping farmland
[Objective]This study aims to investigate the effects of various tillage practices on soil carbon dioxide(CO2)emissions in red soil sloping farmland in order to establish a theoretical foundation for developing a sustainable,low-carbon farming model and optimizing agricultural practices in this type of terrain.[Methods]By setting up experimental plots for four typical tillage practices,including cross-slope ridge tillage(RT),down-slope tillage(DT),plastic mulching(PM),and conventional tillage(CT),a structural equation model was established to explore the relationship between soil physicochemical properties and soil CO2 emissions.Additionally,a comprehensive evaluation model was utilized to quantitatively analyze the carbon reduction and yield increase benefits of different tillage practices.[Results]The soil organic carbon and total nitrogen contents of the soil in the RT treatment were generally higher,which significantly increased the total porosity of the soil and reduced soil bulk density(p＜0.05).Conversely,these parameters were the opposite in the DT treatment.The soil temperature and moisture content in the PM treatment were significantly higher than those in the other tillage practices,and the soil temperature and moisture content in the ridge treatments represented by RT and DT were significantly higher than those in CT.During the crop growth period,the soil CO2 emission flux under different tillage practices ranged from 60.53 to 818.90 mg/(m2·h),showing a fluctuating trend of first increasing and then decreasing.The cumulative soil CO2 emissions among the different tillage practices decreased in the order:PM＞DT＞CT＞RT,with RT significantly reducing emissions by 3.4％to 22.4％(p＜0.05).The emission levels during the crop growth stages decreased in the order:granulation stage＞ear stage＞seedling stage.Rainfall erosion had a significant Birch effect on soil CO2 emissions in red soil sloping farmland.After rainfall erosion,the soil CO2 emission flux among different tillage practices decreased in the order:DT＞PM＞CT＞RT in red soil sloping farmland.Soil CO2 emission flux was mainly influenced by adjustments in soil temperature,soil moisture content,total nitrogen,and bulk density.[Conclusion]RT plays a positive role in reducing soil CO2 emissions and increasing crop yield,is a favorable practice in southern red soil sloping farmland.
soil CO2 emissionstillage practicesred soil sloping farmlandcrop growth period
国家科技期刊平台
NSTL
万方数据
