【摘要】 通过布置室内盆栽试验,观测不同N、P肥施用量处理对不同母质和肥力水平红壤水稻土微生物生物量C、N和基础呼吸强度的影响。结果表明,不同红壤水稻土速效养分含量随施肥量的增加而增加,但微生物生物量、呼吸强度和呼吸熵并不一直呈上升趋势。第三纪和第四纪高肥水稻土微生物生物量C在超过2倍常规施肥量后呈下降趋势,第三纪低肥水稻土则随施肥量增加而呈上升趋势。不同土壤的微生物生物量N则在超过1.5倍常规施肥量后呈下降趋势,不同土壤间微生物生物量N变化表现为第四纪高肥水稻土>第三纪高肥水稻土>第三纪低肥水稻土。施肥条件下,红壤水稻土的基础呼吸强度在超过1.5倍常规施肥量后,即随施肥量增加而下降。但土壤呼吸熵随施肥量变化并没有一致的规律。更多还原

【Abstract】 Influences of fertilization on soil microbial biomass C,N and basic respiration intensity were investigated through a greenhouse pot experiment using paddy soils derived from diffenent parent materials and with different fertility levels in subtropical China.Results showed that soil available nutrient contents increased with the fertilizer application rates,but soil microbial biomass,respiration intensity and metabolic quotient did not always show the same tendency.Microbial biomass C content in paddy soils with high fertility level derived from Quaternary red clay(CH)and from Tertiary sandstone weathering product(SH)decreased when the fertilizer application rate was doubled or more than doubled over the conventional one,whereas in paddy soils with low fertility level and derived from Tertiary sandstone weathering product(SL),it increased with the fertilizer application rate.Microbial biomass N contents in all the paddy soils,regardless of fertility level or parent materials,decreased when the fertilizer application rate was 1.5 times or more as high as the conventional rate.In terms of magnitude of the changes in microbial biomass N contents,the paddy soils followed the orders of CH>SH>SL.Basic respiration intensities of the paddy soils were all decreased when the application rate exceeded 1.5 times as high as the conventional one.However,soil metabolic quotient remained unchanged in spite of changes in fertilizer application rates.更多还原