We conducted a meta-analysis to analyze the effects of nitrogen (N) and combined N and phosphorus (N+P) addition on soil enzyme activities, which being involved in soil carbon (C), N, and P cycles as well as oxidative processes. Nitrogen addition significantly increased the activities of soil C acquisition enzymes, N acquisition enzymes, and P acquisition enzymes by 6.9%, 5.6% and 10.7%, respectively, while the enhancement was much stronger under N+P treatment with 13.4%, 37.4% and 13.3%, respectively. In contrast, both N addition and N+P addition decreased the activities of oxidative enzymes by 6.1% and 0.4%, respectively. The effect sizes of N and N+P addition on soil enzyme activities varied with ecosystem types, N fertilizer types, N addition rates, and the duration of fertilization experiments. Our results suggested that the changes in soil microbes and their enzymes under increasing N deposition and P addition would have profound impacts on soil biogeochemical processes and functions.
本文通过整合分析(Meta-analysis)的方法分析了氮、磷添加对土壤碳、氮和磷素循环水解酶以及土壤氧化酶活性的影响.结果表明: 氮添加显著增加了碳、氮和磷循环水解酶的活性,增幅分别为6.9%、5.6%和10.7%;与氮添加相比,在氮磷同时添加下,3类土壤酶的活性增加更为显著,增幅分别达13.4%、37.4%和13.3%.然而,对于土壤氧化酶,氮以及氮磷的添加都使其活性降低,分别降低了6.1%和0.4%.不同生态系统类型、氮肥类型、施肥速率和施肥试验时间都对土壤酶活性具有影响.在全球大气氮沉降与磷添加逐渐增加的背景下,土壤微生物活性和酶的变化将会对土壤生物地球化学循环过程和土壤生态系统功能产生重要影响.
Keywords: nitrogen and phosphorus addition; nitrogen deposition; soil enzyme activity; terrestrial ecosystem.