干湿交替对水稻土碳氮矿化的影响  

Carbon and Nitrogen Mineralization of Paddy Soils as Affected by Wetting and Drying

作　　者：刘艳丽[1] 张斌[1] 胡锋[2] 乔洁[1] 张卫健[3] 

机构地区：[1]中国科学院南京土壤研究所,南京210008 [2]南京农业大学资源与环境学院,南京210095 [3]南京农业大学农学院,南京210095

出　　处：《土壤》2008年第4期554-560,共7页Soils

基　　金：国家自然科学基金(40371059)资助

摘　　要：通过室内培育试验，研究干湿交替条件下长期不同施肥处理水稻土微生物生物量和理化性状变化对土壤C、N矿化的影响机制。结果表明，与连续淹水（CW）处理相比，干燥处理不仅显著地提高了所有施肥处理土壤有机C的矿化速率，其幅度为78％～204％，而且也提高了各处理土壤微生物生物量C和N，其幅度分别为55％～77％和57％～72％；干燥后淹水处理土壤有机C矿化速率的提高幅度为74％～95％，呈先降低再升高的趋势。土壤N的矿化在干湿交替过程的干燥处理中降低34％～78％；干燥后淹水过程仅使NPK处理的升高21％，而CK和NPKOM处理分别降低5％和13％。在培养过程中土壤Eh值仅在-60～60mV范围时，与土壤微生物生物量C之间有显著的负相关关系。在干湿交替的干燥过程，随土壤pH值的升高土壤微生物生物量C有增加的趋势，在淹水条件下土壤pH值则仅与NPKOM处理土壤微生物生物量C之间有明显的负相关关系。干湿交替条件下土壤pH和Eh值、微生物群落组成和数量与有机质的矿化之间的相互作用关系复杂，三者间的作用机理需进一步研究。The effects of wetting and drying on paddy soil carbon （C） and nitrogen （N） mineralization were investigated by soil microbial biomass and physical-chemical condition under different long-term fertilizer treatments with incubation experiments. Results indicated that compared withcontinuous wetting （CW） period, not only did C mineralization rate in drying period with drying and wetting （DW） increased by 78% - 204% for all the soils, but also soil microbial biomass C and N increased by 55% - 77% and 57% - 72%, respectively. In rewetting period C mineralization rate increased by 74% - 95%, with the trend of decrease followed increase. N mineralization rate in rewetting period increased by 21% for NPK, while it decreased by 5% and 13% for CK and NPKOM, and it decreased by 34% - 78% in drying treatment for all the fertilizer treatments. During incubation period, soil Eh value in the range of -60 ～ 60 mV had negative correlation with soil microbial biomass C （SMBC）. In the process of drying with DW, pH value increased with soil microbial biomass C growth. In the wetting period, pH value was negatively correlative with soil microbial biomass C only in NPKOM treatment. Further research is needed to assess the interactive correlations between C and N mineralization, Eh and pH value, and soil microbial community and biomass under the alternative flooding and drying cycles because they are complex and intricate.

关 键 词：CO2释放 长期施肥试验 生物性质 干湿交替 水稻土 

分 类 号：S147[农业科学—肥料学]