State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, East Beijing Road No. 71, Nanjing 210008, China; University of Chinese Academy of Sciences, Yuquan Road No. 19A, Beijing 100049, China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, East Beijing Road No. 71, Nanjing 210008, China.
Sci Total Environ. 2022 Sep 10;838(Pt 3):156532. doi: 10.1016/j.scitotenv.2022.156532. Epub 2022 Jun 6.
Soil extracellular enzyme activities of microbes to acquire carbon (C), nitrogen (N) and phosphorus (P) exert great roles on soil C sequestration and N, P availability. However, a lack of biochar-induced changes of C, N and P acquisition enzyme activities hinders us from understanding if biochar application will lead to microbial C, N and P limitation based on ecoenzymatic stoichiometry. In this study, through ecoenzymatic stoichiometry, a meta-analysis was conducted to evaluate responses of microbial metabolic limitation to biochar amendment by collecting data of ecoenzymatic activities (EEAs) of the C, N and P acquisition from peer-reviewed papers. The results showed that biochar application increased activities of C, N acquisition enzymes significantly by 9.3 % and 15.1 % on average, respectively. But the influence on P acquisition enzymes activities (Acid, neutral or alkaline phosphatase, abbreviated wholly as PHOS) was not significant. Biochar increased ratio of C acquisition enzymes activities (E) over P enzymes activities (E) and ratio of N enzymes activities (E) over E, but decreased E:E, indicating an increased N limitation or a shift from P limitation to N limitation in microbial metabolism. Enzyme vector analysis showed that soil microbial metabolism was limited by C relative to nutrients (N and P) under biochar amendment according to the overall increased vector length (~1.5 %). Wood biochar caused the strongest microbial C limitation, followed by crop residue biochar as indicated by increased enzyme vector length of 3.6 % and 1.2 % on average, respectively. The stronger microbial C limitation was also found when initial soil total organic carbon (SOC) was <20 g·kg. Our results illustrated that available nitrogen and organic carbon should be provided to meet microbial stoichiometric requirements to improve plant productivity, especially in low fertile soils under biochar amendment.
土壤微生物获取碳（C）、氮（N）和磷（P）的胞外酶活性对土壤碳固存以及氮、磷有效性具有重要作用。然而，生物炭对碳、氮和磷获取酶活性的影响缺乏了解，这阻碍了我们从生态酶化学计量学的角度来理解生物炭的应用是否会导致微生物的碳、氮和磷限制。在这项研究中，通过生态酶化学计量学，我们通过收集同行评议文献中生态酶活性（EEAs）的 C、N 和 P 获取数据，进行了一项荟萃分析，以评估微生物代谢限制对生物炭添加的反应。结果表明，生物炭应用平均分别增加了 9.3%和 15.1%的 C 和 N 获取酶活性。但对 P 获取酶活性（酸性、中性或碱性磷酸酶，简称 PHOS）的影响并不显著。生物炭增加了 C 获取酶活性（E）与 P 酶活性（E）的比值以及 N 酶活性（E）与 E 的比值，但降低了 E:E，表明微生物代谢中氮限制增加或从 P 限制转变为 N 限制。酶向量分析表明，根据整体增加的向量长度（~1.5%），土壤微生物代谢受到生物炭添加下相对养分（N 和 P）的 C 限制。与作物残渣生物炭相比，木质生物炭导致了最强的微生物 C 限制，平均分别增加了 3.6%和 1.2%的酶向量长度。当初始土壤总有机碳（SOC）<20 g·kg 时，也发现了更强的微生物 C 限制。我们的研究结果表明，应该提供可用的氮和有机碳来满足微生物的化学计量需求，以提高植物生产力，特别是在生物炭添加下的低肥沃土壤中。
