Organic carbon quality, composition of main microbial groups, enzyme activities, and temperature sensitivity of soil respiration of an acid paddy soil treated with biochar
Organic carbon quality, composition of main microbial groups, enzyme activities, and temperature sensitivity of soil respiration of an acid paddy soil treated with biochar
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DOI：
10.1007/s00374-018-1333-2
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发表时间：
2019-02-01
影响因子：
6.5
通讯作者：
Sun, Xuan
中科院分区：
文献类型：
--
作者：
Chen, Junhui;Chen, De;Sun, Xuan
在生物炭应用下，土壤有机碳(SOC)质量对微生物群落组成和功能的影响还知之甚少。我们在15℃、25℃和35℃的室内试验中，研究了有机碳库大小与有机碳化学组成、主要微生物类群组成、参与C、N、P循环的酶活性以及土壤呼吸作用之间的关系。用~(13)C-核磁共振波谱测定了SOC的化学组成。20和40THA(-1)的生物炭改良剂显著降低了土壤活性C库I(用5N H_2SO_4提取)、烷基和羰基C含量，增加了顽固性C库(耐酸)和芳香族C含量以及芳香族C/O-烷基C的比值。在10和20tha(-1)施用量下，磷脂-脂肪酸浓度和土壤酶活性没有变化，但在40tha(-1)施用量下，磷脂-脂肪酸浓度和土壤酶活性均有所增加。生物炭提高了革兰氏阳性菌(G+)与革兰氏阴性菌(G-)的比例，降低了真菌与细菌的比例。顽固性C库和芳香族C含量与G+菌丰度呈正相关，是形成主要微生物类群组成和提高酶活性的重要因素。在40 THA(-1)温度下，生物炭通过减少土壤活性碳库和增加C顽固性，降低了15℃和25℃下的土壤呼吸速率，而通过刺激微生物丰度和酶活性，增加了25/15℃和35/25℃下土壤呼吸的温度敏感性。综上所述，我们的结果表明，生物炭土壤改良剂通过影响土壤有机碳的组成，改变了微生物群落的组成和功能。
The role of soil organic C (SOC) quality affecting microbial community composition and function under biochar application is poorly understood. We investigated the relationship between the pool size and chemical composition of SOC; composition of main microbial groups; enzyme activities involved in C, N, and P cycling; and soil respiration in a rice paddy amended with biochar for 20months in a laboratory experiment at 15, 25, and 35 degrees C. Soil labile and recalcitrant organic C pools were determined by a two-step sulfuric acid (H2SO4) hydrolysis method. The chemical composition of SOC was determined with C-13-nuclear magnetic resonance spectroscopy. The biochar amendment at 20 and 40tha(-1) significantly decreased the soil labile C pool I (extracted by 5N H2SO4), alkyl, and carbonyl C contents and increased the recalcitrant C pool (acid-resistant) and aromatic C contents and the aromatic C to O-alkyl C ratio. The phospholipid-fatty acid concentrations and soil enzyme activities were unchanged by biochar application at 10 and 20tha(-1), but both were increased at 40tha(-1). Biochar increased the ratio of gram-positive (G+) to gram-negative (G-) bacteria and decreased that of fungi to bacteria. The recalcitrant C pool and aromatic C contents were positively correlated to the G+ bacteria abundance and were important factors in shaping composition of the main microbial groups and improving enzyme activities. Biochar application at 40tha(-1) lowered soil respiration rates at 15 and 25 degrees C by decreasing labile C pool and increasing C recalcitrancy while increased temperature sensitivities of soil respiration at 25/15 degrees C and 35/25 degrees C by stimulating microbial abundance and enzyme activities. Together, our results suggest that biochar soil amendment shifted microbial community composition and function through influencing the composition of SOC.