Biochar exerts negative effects on soil fauna across multiple trophic levels in a cultivated acidic soil
Biochar exerts negative effects on soil fauna across multiple trophic levels in a cultivated acidic soil
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生物炭对酸性土壤中多个营养级的土壤动物产生负面影响
DOI：
10.1007/s00374-020-01436-1
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发表时间：
2020-01-31
影响因子：
6.5
通讯作者：
Liu, Manqiang
中科院分区：
文献类型：
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作者：
Liu, Ting;Yang, Lihua;Liu, Manqiang
生物炭的应用被认为是一项有前途的农业技术，但对土壤生态系统的风险评价主要集中在土壤微生物上，微食物网是否也受到生物炭的影响尚不清楚。我们进行了一项为期2年的油菜籽盆栽试验，以测试生物炭施用量（0，20，60吨公顷），有或没有氮（N）肥料（0，60，120吨公顷），如何影响土壤微生物和微型动物（原生生物和线虫）。我们观察到，大量的生物炭（60 t ha−1）增加了作物生产力，微生物活性，生物量碳（C）和N，以及鞭毛虫（原生生物）的丰度，但减少了食细菌，食真菌和食草线虫的丰度以及变形虫（原生生物）的丰度。高生物炭添加率也改变了线虫群落组成的食真菌优势，有利于食草动物的比例降低，以草食性线虫。然而，氮肥及其与生物炭的相互作用通常对微生物活性和生物量以及原生动物和线虫的丰度没有影响。结构方程模型表明，生物炭对土壤生物区系的影响在很大程度上是直接的，这可能取决于生物炭的性质（例如，孔隙大小和碱度），而间接影响，介导的作物，土壤pH值，土壤水分和多环芳烃（PAH）浓度，一般没有影响土壤生物群。我们的结论是，生物炭是一种合适的土壤改良剂，以增加作物生长，但其对土壤动物的多营养水平的有害影响，要求确定最佳的应用率和大小部分，可以尽量减少对某些土壤群落的潜在负面影响。
Biochar application is perceived as a promising agricultural technology, but risk evaluation on the soil ecosystem has focused exclusively on soil microbes, whether microfood-web is likewise influenced by biochar remains unclear. We carried out a pot experiment planted with rapeseed for 2 years to test how biochar application (0, 20, 60 t ha−1), with or without nitrogen (N) fertilizer (0, 60, 120 t ha−1), affected soil microbes and microfauna (protists and nematodes). We observed that a high amount of biochar (60 t ha−1) increased crop productivity, microbial activity, and biomass carbon (C) and N, as well as the abundance of flagellates (protists), but decreased the abundances of bacterivorous, fungivorous, and herbivorous nematodes as well as the abundance of amoebae (protists). High biochar addition rates also shifted nematode community composition toward a fungivore dominance, and favored herbivores by decreasing the ratio of microbivorous to herbivorous nematodes. However, N fertilizer and its interaction with biochar generally had no effect on microbial activity and biomass as well as the abundance of protist and nematode. A structural equation model revealed that the effects of biochar on soil biota were largely direct, which might depend on biochar properties (e.g., pore size and alkalinity), whereas indirect effects, mediated by crop, soil pH, soil moisture, and polycyclic aromatic hydrocarbon (PAH) concentration, generally had no effect on soil biota. We conclude that biochar is a suitable soil amendment for increasing crop growth, but its detrimental effect on multitrophic levels of soil fauna calls for an identification of the optimal application rate and size fraction that could minimize potential negative effects on certain soil communities.