炉渣与生物炭施加对稻田土壤碳库及微生物的影响

Subsequent effects of slag and biochar application on soil carbon pools and soil microoganisms in paddy fields

以福州平原稻田为实验区,在2015年早、晚稻秧苗移栽前,对稻田进行施加生物炭、炉渣、生物炭+炉渣(混施)处理,并以不施加处理作为对照。为了了解施加处理的后续效应,于2017年检测早、晚稻拔节期和成熟期土壤有机碳含量及真菌、细菌数量。结果表明:3种施加处理稻田土壤有机碳(SOC)含量均比对照组有显著提高(P<0.05),但溶解性有机碳(DOC)、易氧化碳(EOC)、土壤微生物量碳(MBC)含量各处理之间差异不显著(P>0.05)。与对照组相比,各施加处理组在一定程度上提高了土壤中真菌和细菌数量,但差异不显著(P>0.05)。细菌数量与DOC含量呈极显著负相关(P<0.01),与EOC含量呈显著负相关(P<0.05),与MBC含量呈显著正相关(P<0.05)。真菌/细菌比值与真菌数量、DOC含量呈极显著正相关(P<0.01)。说明炉渣和生物炭施加处理2年后,仍可提高稻田土壤的碳库稳定性,并增加土壤微生物数量。

Using the Fuzhou Plain paddy as the research area,biochar,slag,and biochar+slag(mixed application)were applied to the paddy before the transplantation of early and late rice seedlings in 2015.A no amendment treatment was used as a control.To understand the subsequent effects of the treatments,the soil organic carbon content and the number of fungi and bacteria were tested for during the rice jointing and maturity stages of the early and late paddy fields in 2017.The results showed:The soil organic carbon(SOC)content of the three applied treatments was significantly higher than that of the control group(P<0.05).However,there was no significant difference among the treatments in dissolved organic carbon(DOC),easily oxidized carbon(EOC),and soil microbial biomass carbon(MBC)(P>0.05).Compared with the control group,each application treatment group showed an increase in the number of fungi and bacteria in the soil to some extent;however,the difference was not significant(P>0.05).There was a significant negative correlation between the number of bacteria and DOC(P<0.01),a significant negative correlation with EOC(P<0.05),and a significant positive correlation with MBC(P<0.05).The fungal/bacterial ratio was significantly positively correlated with the number of fungi and DOC(P<0.01).This showed that improvement in the stability of carbon storage in paddy soil and the increase in the number of soil microorganisms still occurred 2 years after the application of slag and biochar.