生物炭对土壤氮循环的影响研究进展

在定性资料调研的基础上,基于ISI Web of Science数据库,采用文献计量学方法,针对"生物炭对土壤氮循环的影响"及其分支技术进行文献检索、数据整理、分类以及主题分析,从国际整体研究态势和分支技术主题两个角度探讨了目前国内外生物炭影响土壤氮循环方面的研究进展,并从生物炭对土壤N_2O排放、肥料利用率、硝化速率、NH_4~+/NH_3吸附、NO_3~-吸附以及土壤微生物氮素固持等6个方面的影响进行了详细论述。近年来,生物炭对土壤氮循环的影响研究急剧增温,发文量逐年增加,截止2014年6月,SCI数据库中共检索到2468篇论文。其中,期刊论文2188篇、综述性论文93篇,其它类论文177篇。美国、加拿大、英国等欧美国家在该领域的研究中占有明显优势,而自2010年以来,中国已成为该领域全球第一的年发文大国。发文热点主要集中在生物炭对土壤N_2O排放和对氮肥利用率的影响2个方面,占总发文量的73.7%。从6个方面的分支技术主题来看,生物炭的影响作用争议性较大。大部分研究认为,生物炭能够抑制土壤N_2O排放、提高氮肥利用率、促进土壤硝化速率、提高土壤对NH_4~+/NH_3和NO_3~-的固持作用以及土壤微生物氮素固持作用等,但也有研究表明生物炭会促进土壤N_2O排放、抑制土壤硝化速率,且不具备NO_3~-固持能力。这主要与生物炭的类型、老化过程,以及土壤类型及其含水孔隙率等密切相关。总之,探讨了生物炭对土壤氮循环影响的研究动态、热点及主要结论,为深入了解生物炭对土壤理化特性影响的作用机制提供了一定研究思路,为生物炭的农业应用提供了一定借鉴和参考。

Effect of biochar on soil nitrogen cycling: a review

This mini-review paper based on the ISI Web of Science database and employed the literature retrieval metrology in combination with inventory of qualitative data and summarized the effects of biochar on soil nitrogen cycling. Based on the effects of biochar on soil nitrogen cycling and searching of branch topics, data arrangement, paper classification and topics analysis, this paper gave a detailed overview of research progress of biochar effect on soil nitrogen cycling overall international research status as well as in different branch topics both in China and abroad. The main aspects included were:biochar effect on N₂O emission, nitrogen use efficiency, nitrification rates, adsorption of soil inorganic nitrogen (ammonium/ammonia and nitrate) and nitrogen retention by microbes. Nowadays, the developments of effects of biochar on soil nitrogen cycling were quickly and the number of published papers were also increased. ISI Web of Science database were used as a basis to retrieve the Scientific Citation Indexed (SCI) papers and a total of 2468 SCI articles were published until June 2014, including articles (2188), review papers (93) and others (177). The European and America countries such as America, Canada and Britain occupied the obvious advantages in this researching field and China has become the first country to published papers in this field since 2010. Meanwhile, the papers mainly focused on effects of biochar on soil N₂O emission and nitrogen use efficiency, accounting for 73.7% of the total number. From the perspective of the above six branches, it is controversial about the effects of biochar on them. Most of the reports indicated that biochar could inhibit soil N₂O emission, and improve the nitrogen use efficiency, the soil nitrification rate, the retention of NH₄⁺/NH₃/NO₃^- and soil nitrogen assimilation by microbes. However, some contrary studies suggested that biochar could increase soil N₂O emission, inhibit soil nitrification rate and have no ability to adsorb NO₃^-. Biochar type, biochar aging, soil type and soil water porosity were the main factors affecting the influence of biochar on soil nitrogen cycling. This paper discussed the dynamic and hot pots together with some main conclusions of biochar affecting soil nitrogen cycling comprehensively. It sheds lights on a better understanding of mechanisms of biochar effects on soil physiochemical properties. Moreover, it provides some certain references to agriculture application for biochar.