施用生物炭对农田生态系统影响的研究进展

Research Advances in Effects of Biochar Application on Agroecosystem

从施用生物炭对土壤理化性状、土壤生物、土壤碳截留、作物产量、温室气体排放的影响等方面,总结分析了施用生物炭对农田生态系统的影响。结果表明,施用生物炭能够改善土壤理化特性和微生物生境,提高养分利用率,但对作物的增产效应具有一定的不确定性。生物炭的稳定性对增加农田土壤碳截留有重要作用,其降解过程目前尚不清楚。添加生物炭影响土壤有机质分解即激发效应,但激发效应的方向和幅度的变异较大。在影响温室气体排放方面,施用生物炭能有效减少N2O排放,但对CO2和CH4的减排效应具有较大的不确定性,生物炭的性质、施用量、土壤类型和肥力状况等因素是导致这些不确定性的主要原因,今后应综合考虑以上因素开展长期定位试验,客观评价生物炭对农田生态系统功能的影响和作用。

In this paper,the current studying progresses about the effects of biochar application on agro-ecosystem with respect to soil physicochemical properties, soil microbes, carbon sequestration, crop productivity, and greenhouse gases （GHGs） emission were reviewed. In summary, biochar application could improve soil fertility, soil biota habitat and nu- trient use efficiency （nitrogen, phosphorus）. On the other hand, there was still some uncertainty about the effects of bio- char application on crop productivity （ either yield or above-ground biomass）. The stability of biochar played a key role in soil carbon accumulation ,whereas the detailed degradation process of biochar had not been fully understood. Biochar affected the decomposition of native soil organic matter, known as the priming effect,while the priming direction （ posi- tive or negative） and magnitude varied by soil and biochar types. Considering the GHGs emission, the influence of bio- char application on soil respiration and CH4 evolution had some uncertainty, whereas biochar application was proved to be effective in mitigating N20 emissions. These uncertainties mentioned above might be explained by the differences in biochar properties, application rates, soil types and fertility conditions. Thus,long-term field experiments should be car- ried out in order to evaluate the influences and functions of biochar amendment objectively.