甘薯不同轮作模式对土壤有机碳组分及碳转化酶活性的影响

Effects of Different Rotation Modes of Sweet Potato on Soil Organic Carbon Components and Carbon Conversion Enzyme Activities

为探究甘薯不同轮作模式对土壤有机碳组分及碳转化酶活性的影响,以甘薯-小麦连作3 a地块为研究对象,设置甘薯-小麦连作(SWS)、甘薯-小麦/甘薯-油菜轮作(SWR)、甘薯-小麦/玉米-小麦轮作(SWC)、甘薯-小麦/花生-小麦轮作(SWP)4个处理,研究不同轮作模式对0~20 cm、20~40 cm土壤有机碳组分及碳转化酶活性的影响,并探讨其相关性。结果表明,与SWS处理相比,SWR、SWC、SWP处理能够提高0~20、20~40 cm土壤有机碳(SOC)、可溶性有机碳(DOC)、颗粒有机碳(POC)、易氧化有机碳(ROC)、微生物量碳(MBC)含量以及土壤蔗糖酶、纤维素酶、多酚氧化酶、过氧化物酶活性,整体上提升了0~20、20~40 cm土壤POC、DOC、ROC及MBC占比。不同轮作处理土壤有机碳及其组分含量、碳转化酶活性差异也较明显。0~20 cm土层,SWC处理ROC含量较SWR、SWP处理分别显著提高5.79%、7.56%,蔗糖酶活性分别显著提高7.20%、8.71%;SWR处理DOC含量较SWP处理显著提高5.67%;SWP处理MBC含量较SWR、SWC处理分别显著提高5.93%、10.35%,过氧化物酶活性较SWR、SWC处理分别显著提高11.89%、7.02%。20~40 cm土层,SWC处理POC、ROC含量及蔗糖酶活性较SWP处理分别显著提高5.07%、5.42%、9.48%,多酚氧化酶、过氧化物酶活性较SWR处理分别显著提高5.93、7.14%;SWR处理DOC含量及蔗糖酶活性较SWP处理分别显著提高5.93%、5.65%;SWP处理MBC含量较SWC处理显著提高7.56%,多酚氧化酶、过氧化物酶活性较SWR处理分别显著提高5.56%、12.30%。相关性分析结果表明,不同轮作模式下土壤有机碳及其组分含量与碳转化酶活性有直接或间接关系。综上,甘薯不同轮作模式均可提高土壤有机碳及其组分含量和碳转化酶活性。其中,SWC(甘薯-小麦/玉米-小麦轮作)、SWP(甘薯-小麦/花生-小麦轮作)处理表现明显优于SWR(甘薯-小麦/甘薯-油菜轮作)处理。

In order to investigate the effects of different rotation modes of sweet potato on soil organic carbon components and carbon invertase activity,we took sweet potato‐wheat continuous cropping land for 3 years as the research object,set up four treatments including sweet potato‐wheat continuous cropping(SWS),sweet potato‐wheat/sweet potato‐rapeseed rotation(SWR),sweet potato‐wheat/corn‐wheat rotation(SWC),and sweet potato‐wheat/peanut‐wheat rotation(SWP),studied the effects of different rotation modes on soil organic carbon components and carbon invertase activity in 0—20 cm and 20—40 cm soil layers,and explored their correlations.The main results were as follows:compared with the SWS treatment,the SWR,SWC,and SWP treatments could increase soil organic carbon(SOC),dissolved organic carbon(DOC),particulate organic carbon(POC),readily oxidizable organic carbon(ROC),microbial biomass carbon(MBC)content,and soil sucrase,cellulase,polyphenol oxidase,and peroxidase activity in 0—20 cm and 20—40 cm soil layers.Overall,POC,DOC,ROC and MBC ratios in 0—20 cm and 20—40 cm soil layers were increased.There were also significant differences in soil organic carbon and its component content,as well as carbon conversion enzyme activity among different rotation treatments.In 0—20 cm soil layer,the ROC content and sucrase activity of the SWC treatment were significantly increased by 5.79%,7.56%,and 7.20%,8.71%compared to the SWR and SWP treatments,respectively.The DOC content of the SWR treatment was significantly increased by 5.67%compared to the SWP treatment.The MBC content and peroxidase activity of the SWP treatment were significantly increased by 5.93%,10.35%,and 11.89%,7.02%compared to the SWR and SWC treatments,respectively.In 20—40 cm soil layer,the POC,ROC content and sucrase activity of the SWC treatment were significantly increased by 5.07%,5.42%,and 9.48%compared to the SWP treatment,and the activities of polyphenol oxidase and peroxidase of the SWC treatment were significantly increased by 5.93%and 7.14%compared to the SWR treatment,respectively.The DOC content and sucrase activity of the SWR treatment were significantly increased by 5.93%and 5.65%compared to the SWP treatment,respectively.The MBC content of the SWP treatment was significantly increased by 7.56%compared to the SWC treatment,and the activities of polyphenol oxidase and peroxidase of the SWP treatment were significantly increased by 5.56%and 12.30%compared to the SWR treatment,respectively.The result of correlation analysis showed that there was a direct or indirect relationship between the soil organic carbon and its components and carbon conversion enzyme activity under different rotation modes of sweet potato.In summary,the different rotation patterns of sweet potato could increase the content of soil organic carbon and its components,as well as the activity of carbon conversion enzymes.Among them,the SWC(sweet potato‐wheat/corn‐wheat rotation)and SWP(sweet potato‐wheat/peaunt‐wheat rotation)treatments performed significantly better than the SWR(sweet potato‐wheat/sweet potato‐rapeseed rotation)treatment.