炉渣与生物炭配施对稻田土壤性质及微生物特征的影响

稻田土壤微生物种类多、数量大,是土壤有机碳矿化的驱动者和有机碳库的固持者。以福州平原稻田为试验样地,分别施加生物炭、炉渣、生物炭+炉渣3种处理,测定分析不同处理对稻田土壤理化性质、微生物数量及有机碳含量的影响,旨在探究稻田土壤微生物在土壤碳库稳定方面的作用。结果表明:(1)炉渣与生物炭施加能够增加稻田土壤微生物数量,提高土壤真菌/细菌比值,有利于土壤碳库稳定性,其中混合施加效果更为显著。(2)3种施加处理均使早稻拔节期真菌数量及真菌/细菌比值显著升高,其中真菌/细菌比值分别提高0.016,0.015,0.018,同时使晚稻乳熟期厌氧细菌数量显著增加。生物炭单一施加及混施处理使晚稻拔节期好氧细菌数量显著升高。混施处理使早稻乳熟期好氧细菌数量显著升高(p<0.05)。(3)炉渣施加处理显著提高了早稻乳熟期土壤DOC的含量,生物炭施加处理显著提高早稻乳熟期土壤SOC含量,混施处理使早稻拔节期土壤SOC含量显著升高,使晚稻拔节期土壤DOC显著升高(p<0.05),并且早、晚稻拔节期有机碳含量显著高于乳熟期。(4)稻田土壤理化性质、微生物数量及有机碳含量三者相互影响,早稻土壤pH与土壤MBC含量呈显著负相关,与真菌数量呈极显著正相关(p<0.01)。晚稻土壤含水量与DOC、好氧细菌、厌氧细菌、真菌呈正相关。MBC与厌氧细菌呈显著负相关(p<0.05)。

Effects of Combined Application of Slag and Biochar on Soil Properties and Microbial Characteristics in Paddy Fields

Paddy soil has many kinds and large quantities of microbes, which will drive soil organic carbon mineralization and hold organic carbon pool. In this study, the paddy fields in Fuzhou Plain were used as test plots, and three kinds of treatments, such as biochar, slag, and biochar+slag, were applied to determine the effects of applied treatments on soil physical and chemical properties, microbial quantity, and organic carbon content in paddy fields, and the microbial role in the stabilization of soil carbon pools. The results showed that:(1) The application of slag and biochar could increase the quantity of microbes in paddy soil and the ratio of fungi/bacteria in soil, which was beneficial to the stability of soil carbon pool, and the effect of mixed treatments was more significant. (2) The three application treatments significantly increased the quantity of fungi and fungi/bacteria ratio in early rice jointing stage, and the fungi/bacteria ratio increased by 0.016, 0.015, and 0.018, respectively. The bacteria quantity was increased significantly. The single application and mixed treatments of biochar increased the quantity of aerobic bacteria in late rice jointing stage. The mixed application treatment significantly increased the quantity of aerobic bacteria in early maturity (p<0.05). (3) The slag application treatment significantly increased the soil DOC content in the early rice maturity stage, and the biochar application treatment significantly increased the soil SOC content in the early rice maturity stage. The mixed application treatment significantly increased the soil SOC content in the early rice jointing stage. Soil DOC significantly increased in the late rice jointing stage (p<0.05).The content of organic carbon in the early and late rice jointing stage was significantly higher than that in the maturitystage. (4) The physical and chemical properties, microbial quantity, and organic carbon content of paddy soils were positively affected. The soil of early paddy soil was significantly negatively correlated with soil MBC content, and it was significantly positively correlated with the quantity of fungi (p<0.01). The soil moisture content of late rice was positively correlated with DOC, aerobic bacteria, facultative anaerobic bacteria, and fungi. There was a significant negative correlation between MBC and anaerobic bacteria (p<0.05).