炉渣与生物炭施加对稻田温室气体排放及其相关微生物影响

为了减少稻田温室气体排放通量,本研究对稻田土壤进行炉渣和生物炭单一施加和混合施加处理,并测定了早、晚稻拔节期和乳熟期CO_2、CH_4和N_2O排放通量及相关微生物(细菌、真菌、硝化细菌、反硝化细菌)的数量.结果表明,稻田施加废弃物可以减少温室气体的排放通量.在早、晚稻的拔节期,施加生物炭显著降低了CO_2和N_2O的排放通量(p0.05),混合施加显著降低了CO_2和CH_4的排放通量(p0.05),施加炉渣条件下3种温室气体的排放通量与对照组相比没有差异.施加炉渣或生物炭都显著降低硝化细菌的数量(p0.05),混施处理显著降低细菌、硝化细菌、反硝化细菌数量(p0.05),但显著提高了稻田土壤真菌/细菌比值(p0.05).在早、晚稻的乳熟期,炉渣、生物炭、混施处理能显著降低CH_4排放通量(p0.05),而生物炭处理显著降低N_2O排放通量(p0.05).炉渣处理显著降低细菌、硝化细菌、反硝化细菌数量(p0.05),生物炭处理显著降低细菌、反硝化细菌数量(p0.05),混施处理显著降低细菌、硝化细菌数量,并显著提高真菌/细菌比值(p0.05).温室气体排放与微生物数量之间的相关性分析结果表明,CO_2、CH_4排放通量与细菌数量呈显著正相关,与真菌/细菌比值呈显著负相关;而N_2O排放通量则与硝化细菌、反硝化细菌数量呈显著正相关.

Effect of slag and biochar amendment on greenhouse gases emissions and related microorganisms in paddy fields

In order to reduce greenhouse gases emissions in paddy fields, the effect of single and mixed amendment of slag and biochar on CO₂, CH₄ and N₂O emissions and related microorganisms (bacteria, fungal, nitrobacteria and denitrobacteria) were determined in elongation and ripen stage both early and late paddy fields. The results showed that greenhouse gases emissions were reduced after waste amendment. In the elongation stage of both early and late paddy fields, CO₂ and N₂O emissions significantly decreased after biochar amendment (p<0.05), and CO₂ and CH₄ emissions significantly decreased after mixed amendment (p<0.05). The three greenhouse gas emissions were however not significantly different after slag amendment comparison with the control. The populations of nitrobacteria significantly decreased after slag or biochar amendment (p<0.05). After mixed amendment, the populations of bacteria, nitrobacteria and denitrobacteria significantly decreased (p<0.05), while the fungal:bacteria ratio significantly increased (p<0.05). In the ripen stage of both early and late paddy fields, CH₄ emissions significantly decreased by the slag, biochar and the mixed amendment (p<0.05), while N₂O emissions significantly decreased after biochar amendment (p<0.05). The populations of bacteria, nitrobacteria and denitrobacteria significantly decreased after slag amendment (p<0.05), and the populations of bacteria and denitrobacteria significantly decreased after biochar amendment (p<0.05). The populations of bacteria and nitrobacteria significantly decreased (p<0.05), but the fungal:bacteria ratio significantly increased after mixed amendment (p<0.05). Correlation analysis among greenhouse gases emissions and populations of soil microorganisms showed that the populations of bacteria was significantly positively correlated with CO₂ and CH₄ flux. The fungal:bacteria ratio was significantly negatively correlated with CO₂ and CH₄ flux. The populations of nitrobacteria were significantly positively correlated with N₂O flux. The populations of denitrobacteria were significantly positively correlated with N₂O flux.