添加稻草和选择性抑制剂的红壤旱地和稻田可培养微生物的变化

Changes of Culturable Microorganisms in Upland and Paddy Red Soils Following Rice Straw and Selective Inhibitors Amendments

本文探讨了添加稻草和选择性抑制剂下红壤旱地和淹水稻田土壤细菌和真菌数量的动态变化。结果表明,培养期间,旱地土壤中添加稻草（Str）处理细菌和真菌数量比对照（CK）分别增加271.4%~518.8%和2900%~3608%;添加稻草＋放线菌酮（Str＋Ac）处理土壤细菌数量比Str处理增加34.1%~81.4%;添加稻草＋四环素＋链霉素（Str＋Sm＋Tc）处理土壤细菌数量比St r处理下降14.3%~43.5%,而真菌增加17.1%~37.6%。淹水稻田土壤中,St r处理土壤细菌数量比CK增加115.3%~362.2%,而真菌数量下降5.8%~27.8%;Str＋Ac处理土壤细菌和真菌数量与Str处理基本相同;Str＋Sm＋Tc处理土壤细菌数量比Str处理下降39.0%~76.2%。旱地土壤中添加稻草使细菌与真菌（B/F）比率显著下降,而淹水稻田土壤中添加稻草使B/F比率明显升高。阐明旱土中添加稻草后细菌和真菌均参与其分解和转化,而真菌作用占主要,淹水稻田土壤中添加稻草的分解和转化主要为细菌。土壤水分对添加稻草土壤微生物群落变化有较大影响。

The changes of culturable microorganisms in upland and flooded paddy red soils following rice straw and selective inhibitors amendment was studied during a 45 day incubation period at 25℃.The results showed that,compared with the treatment of control（CK）,the amount of culturable bacteria and fungi in the soil amended with rice straw were increased by 271.4% ~ 518.8% and 2900% ~ 3608% respectively,during the incubation period of upland soil,the addition of fungicide actidione increased the amount of culturable bacteria by 34.1% ~ 81.4% compared to the rice straw.In the treatments of the addition of bactericides tetracycline and streptomycin sulphate,the amount of culturable bacteria decreased by 14.3% ~ 43.48% compared to the rice straw,however,the amount of culturable fungi increased by17.1% ~ 37.6%.During the incubation period of the flooded paddy soil,the amount of culturable bacteria increased by 115.3% ~ 362.2% in the treatment of rice straw application,whereas the amount of culturable fungi decreased by 5.8% ~ 27.8%,compared to the control（without rice straw amendment）.The effects of the fungicide actidione on culturable bacteria and fungi were similar to rice straw amendment correspondingly,the amount of culturable bacteria decreased by 39.0% ~ 76.2% in the treatment of the bactericides tetracycline and streptomycin sulphate combined with straw compared to the treatment with rice straw only.In addition,under the condition of the red earth soils amended with rice straw,the ratios of bacteria to fungi content decreased dramatically in upland soil,but increased quickly in flooded paddy soil amended with rice straw.The results illustrated that the application of rice straw had significant effects on the growth of bacteria and fungi in upland soil,and fungi possibly played a key role in the straw decomposition and transformation,but in paddy soil the role may be played by the bacteria.Furthermore,our study suggest that soil microbial community changes were influenced greatly by soil moisture content in red earth soil following amendment with rice straw.