添加秸秆和黑炭对水稻土碳氮转化及土壤微生物代谢图谱的影响

Effects of Straw and Black Carbon Addition on C-N Transformation and Microbial Metabolism Profile in Paddy Soil

通过向水稻土中添加秸秆和黑炭进行水稻盆栽实验(秸秆的添加量为2g/kg和10g/kg,黑炭的添加量为5g/kg和25g/kg),分别在孕穗期和成熟期取样研究土壤碳氮转化及微生物代谢剖面的变化。对土壤有机碳、全氮、铵氮等含量的测定结果显示,秸秆和黑炭均能于一定程度上促进土壤碳氮转化,提高水稻产量;Microresp方法检测的微生物代谢图谱表明,秸秆和黑炭的添加量越大,对微生物的代谢影响越大。造成这些差异的主要原因是添加秸秆和黑炭后微生物对果糖、丙氨酸、乙酰葡萄糖胺和赖氨酸盐酸盐的利用率上升。另外,秸秆对微生物碳和净碳矿化速率的影响显著高于黑炭,而黑炭对水稻产量和土壤固碳的影响更大。

The effects of straw and black carbon addition to paddy soil on carbon and nitrogen transformation were studied in a pot experiment.At booting and mature stages,soil C-N transformation and microbial metabolism profile were analyzed.According to the results of organic carbon,total nitrogen,ammonium concentration,both straw and black carbon addition could promote C-N transformation of paddy soil,thereby enhancing the yield of rice grain to some extent.The results of microbial metabolism identified by Microresp suggested that rising concentrations of straw and carbon had an increasing influence on microbial metabolism.The main reason behind the difference was the higher utilization of fructose,alanine,acetyl glucosamine and lysine-HCl after the soil was amended with straw and black carbon.The effect of straw addition on microbial biomass carbon and net carbon mineralization was significantly higher than that of black carbon.Conversely,black carbon had higher effects on the yield of rice grain and soil carbon sequestration.