秸秆还田与水分管理对稻田土壤微生物量碳、氮及溶解性有机碳、氮的影响

Effect of Rice Straw Incorporation and Water Management on Soil Microbial Biomass Carbon,Nitrogen and Dissolved Organic Carbon,Nitrogen in a Rice Paddy Field

采用田间小区试验,于2011年晚稻季在湖南省长沙县金井镇研究水分管理方式(间歇灌溉和长期淹水)和秸秆还田量(无秸秆还田,低量秸秆还田和高量秸秆还田)对稻田土壤微生物量碳、氮和可溶性有机碳、氮含量的影响。结果表明,在长期淹水的条件下,高量秸秆还田较无秸秆还田可提高土壤微生物量碳、氮和土壤可溶性有机碳、氮的含量;间歇灌溉条件下,低量秸秆还田较高量秸秆还田可提高土壤微生物量碳、氮和土壤可溶性有机碳、氮的含量。无秸秆还田条件下,间歇灌溉处理比长期淹水处理土壤微生物量碳、氮和可溶性有机氮含量高,可溶性有机碳含量低;高量秸秆还田下,长期淹水处理比间歇灌溉处理土壤微生物量碳、氮和可溶性有机碳、氮含量高。不同水分管理方式对不同秸秆还田量下稻田土壤微生物量碳、氮和可溶性有机碳、氮含量影响不同。

A field plot experiment was conducted to study the influences of rice straw incorporation and water management on soil microbial biomass carbon（SMBC） and nitrogen（SMBN） contents and dissolvable organic carbon（DOC） and nitrogen（DON） contents in a rice paddy field during the late rice season in 2011 in Changsha, Hunan province. The results showed that under continuous flooding, SMBC, SMBN, DOC and DON of high rice straw-incorporated treatment（6 t/hm2） were higher than those of no-rice straw-incorporated treatment. Under intermittent flooding, SMBC, SMBN, DOC and DON of low rice straw-incorporated treatment（3 t/hm2） were higher than those of high straw-incorporated treatment. Under no-rice straw amendment, SMBC, SMBN and DON of intermittent flooding treatment were higher than those of continuous flooding treatment, while DOC of intermittent flooding treatment was lower than that of continuous flooding treatment. Under high rice straw amendment treatment, SMBC, SMBN, DOC and DON of continuous flooding treatment were higher than those of intermittent flooding treatment. The experiment indicated that the influences of various water managements on SMBC, SMBN, DOC and DON of rice straw-incorporated or no-rice straw-incorporated treatments were different.