Schmalenberger A, Fox A
Department of Life Sciences, University of Limerick, Limerick, Ireland.
Adv Appl Microbiol. 2016;94:109-59. doi: 10.1016/bs.aambs.2015.10.001. Epub 2015 Dec 11.
Soil amendments with biochar to improve soil fertility and increase soil carbon stocks have received some high-level attention. Physical and chemical analyses of amended soils and biochars from various feedstocks are reported, alongside some evaluations of plant growth promotion capabilities. Fewer studies investigated the soil microbiota and their potential to increase cycling and mobilization of nutrients in biochar-amended soils. This review is discussing the latest findings in the bacterial contribution to cycling and mobilizing nitrogen, phosphorus, and sulfur in biochar-amended soils and potential contributions to plant growth promotion. Depending on feedstock, pyrolysis, soil type, and plant cover, changes in the bacterial community structure were observed for a majority of the studies using amplicon sequencing or genetic fingerprinting methods. Prokaryotic nitrification largely depends on the availability of ammonium and can vary considerably under soil biochar amendment. However, denitrification to di-nitrogen and in particular, nitrous oxide reductase activity is commonly enhanced, resulting in reduced nitrous oxide emissions. Likewise, bacterial fixation of di-nitrogen appears to be regularly enhanced. A paucity of studies suggests that bacterial mobilization of phosphorus and sulfur is enhanced as well. However, most studies only tested for extracellular sulfatase and phosphatase activity. Further research is needed to reveal details of the bacterial nutrient mobilizing capabilities and this is in particular the case for the mobilization of phosphorus and sulfur.
使用生物炭改良土壤以提高土壤肥力和增加土壤碳储量已受到一些高层关注。本文报道了对改良土壤和来自各种原料的生物炭的物理和化学分析，以及对植物生长促进能力的一些评估。较少有研究调查生物炭改良土壤中的土壤微生物群及其增加养分循环和活化的潜力。本综述讨论了细菌在生物炭改良土壤中对氮、磷和硫的循环和活化的贡献以及对植物生长促进的潜在贡献的最新研究结果。根据原料、热解、土壤类型和植物覆盖情况，使用扩增子测序或遗传指纹方法的大多数研究都观察到了细菌群落结构的变化。原核生物硝化作用很大程度上取决于铵的可用性，在土壤生物炭改良下可能会有很大差异。然而，向二氮的反硝化作用，特别是氧化亚氮还原酶活性通常会增强，从而减少氧化亚氮排放。同样，细菌对二氮的固定作用似乎也经常增强。少数研究表明，细菌对磷和硫的活化作用也会增强。然而，大多数研究仅测试了细胞外硫酸酯酶和磷酸酶活性。需要进一步研究以揭示细菌养分活化能力的细节，尤其是磷和硫的活化情况。
