黄土高原果园不同覆盖模式对土壤酶活性的影响

为探究土壤绝对酶活性和相对酶活性在果园不同覆盖模式下的变化特征及相关影响因素，为果园土壤质量评价提供理论依据，本试验以传统清耕(Conventional tillage,CT)为对照，研究秸秆(Corn stalk,CS)、黑麦草(Lolium perenne L. Ryrgrass,RE)和白三叶(Trifolium repens L. White clover，WC)处理下α-葡萄糖苷酶(α-glucosidase，AG)、β-葡萄糖苷酶(β-glucosidase，BG)、β-木糖苷酶(β-xylosidase，BXYL)、纤维二糖苷酶(Cellobiosidase,CBH)、乙酰氨基葡萄糖苷酶(Acetylglucosaminidase,NAG)、亮氨酸氨基肽酶(L-leucine aminopeptidase,LAP)和碱性磷酸酶(Alkaline phosphatase,ALP)变化特征及影响因素。结果表明，覆盖措施不同程度提高了0~40 cm各土层土壤绝对酶活性。AG，BG，BXYL，CBH，NAG和ALP活性表现为CS>RE>WC>CT，LAP表现为WC>CS>RE>CT。不同覆盖下土壤相对酶活性变化与绝对酶活性基本一致。冗余分析表明，土壤酶活性与有机碳、全氮、全磷等土壤理化因子含量正相关，而与pH值和容重负相关，有机碳、硝态氮和铵态氮含量是影响土壤酶活性的关键环境因素。

Effect of Diversity Mulching Model on Soil Enzyme Activities in the Loess Plateau Orchard

To provide a theoretical basis for the evaluation of soil quality and the extension of mulching technology in the orchard,this study investigated the change characteristics of soil absolute enzyme activity and specific enzyme activity and related influencing factors under different mulching models. Compared with conventional tillage (CT),characteristics and influencing factors of seven soil enzyme activities including α-glucosidase,β-glucosidase,β-xylosidase,cellobiohydrolase,acetylglucosaminidase,leucine aminopeptidase and alkaline phosphatase under corn straw (CS),ryegrass (RE) and white clover (WC) were analyzed. The results showed that the orchard mulching increased the absolute enzyme activity of 0~20 cm and 20~40 cm soil in different degrees. The activity of AG,BG,BXYL,CBH,NAG and ALP showed CS>RE>WC>CT,while LAP showed WC>CS>RE>CT. The change of soil-specific enzyme activities per unit of organic carbon under different mulching treatments was consistent with the soil absolute enzyme activity. Redundancy analysis showed that soil enzyme activity was positively correlated with soil nutrient factors such as organic carbon,total nitrogen,total phosphorus,while negatively correlated with soil pH ralue and bulk density. Organic carbon,nitrate nitrogen,and ammonium nitrogen are the key environmental factors affecting soil absolute and specific enzyme activities.