甜樱桃重茬土壤有效养分及酶活性的变化

摘要

To investigate the change of soil available nutrients and enzyme activity in sweet cherry replanted soil,soil mineral elements content in (such like total N,nitrate N,ammonia N,available P and available K) and enzyme activity of (including urease,catalase,alkaline phosphatase and invertase) soil samples from NP (the plot never planted sweet cherry),FP (the plot first planted sweet cherry) and RP (the plot replanted sweet cherry)were measured.The resuits indicated that compared with FP,the content of nitrate N,available P,available K,available B,available Zn,available Fe,available Cu and exchangeable Mg significantly decreased,and the activities of urease and alkaline phosphatase also obviously decreased in RP;With soil depth increasing,the content of mineral elements (except for the content of available Mn,available Fe and exchangeable Ca) and soil enzyme activity including urease and alkaline phosphatase and invertase from in RP significantly decreased,while the exchangeable Ca content increased;Ca/P,Ca/K,Ca/Zn,Zn/Mn and Zn/Mg were imbalanced in RP.Additionally,correhtion analysis showed that the cultivating times was positively correlated with the content of available Mn;Urease and alkaline phosphatase were positively correlated with available K (r =0.848 and 0.880),available P(r =0.856 and 0.932),available B(r =0.744 and 0.761),available Zn(r =0.767 and 0.852) and Cu(r =0.788 and 0.852);Invertase was positively correhted with available K,P and Cu (0.626,0.71 and 0.656);urease,alkaline phosphatase and invertase were negatively correlated with the exchangeable Ca (0.784,0.866 and 0.854).In brief,soil available nutrient contents and enzyme activity significandy decreased by replanted sweet cherry seedlings,and the nutrient proportion was imbalanced.%为了探讨甜樱桃重茬土壤中有效养分以及酶活性的变化,在樱桃苗圃地分别从尚未栽种过甜樱桃苗、正茬、重茬区域采集土壤样品,测定土壤有效养分含量(NO3--N、NH4+-N、速效K、有效P及有效B等)和4种土壤酶(脲酶.、过氧化氢酶、碱性磷酸酶以及蔗糖酶)的活性.结果表明:与樱桃正茬土壤相比,甜樱桃重茬土壤NO3--N、速效K、有效P、有效B、有效Zn、有效Fe、有效Cu、可交换性Mg含量、脲酶以及碱性磷酸酶活性含量显著降低;与正茬土壤相比重茬土壤中随着土层深度的增加,矿质元素含量(除有效Mn、Fe以及可交换性Ca含量外)和4种土壤酶活性显著降低,但可交换性Ca含量上升;樱桃重茬土壤有效养分比例失调,其中Ca/P、Ca/K及Ca/Zn严重失调,其中0～20 cm土层失调比例高达104.93％、140.45％和184.59％,20～40 cm土层失调比例分别为110.03％、178.42％以及144.47％,Zn/Mn和Zn/Mg失调较严重,失调比例高达50％以上.其中相关性分析表明:茬数与有效Mn含量呈线性极显著正相关;脲酶和碱性磷酸酶与速效K、有效P、有效B、有效Zn及有效Cu呈极显著正相关;蔗糖酶与速效K、有效P和有效Cu呈极显著正相关;脲酶、碱性磷酸酶和蔗糖酶与交换性Ca含量呈极显著负相关.总之,重茬土壤的有效养分含量以及土壤酶活性显著降低,养分比例失调.