鸡粪对铜污染土壤微生物生物量碳的影响

Effect of chicken manure on the microbial biomass carbon of copper contaminated soil

采用室内恒温好气培养法，研究了2．0％、4．0％、6．0％添加量鸡粪对铜污染土壤微生物生物量碳的影响。结果表明：向土壤中施入2．0％、4．0％、6．0％的鸡粪后，有机碳总量比对照分别增加了0．85、1．49、2．04倍，而可浸提有机碳含量分别增加了3．13、5．70、8．23倍，鸡粪的添加促进了土壤可浸提有机碳含量的增加，土壤可浸提有机碳含量和鸡粪添加量呈正相关（r=0．994^＊＊，n=12）。各处理土壤有机碳和可浸提有机碳含量随培养时间逐渐下降，90d后有机碳含量趋于稳定；土壤可浸提有机碳含量120d后趋于稳定。鸡粪显著促进了土壤微生物生物量碳含量和土壤微生物商的增加（P〈0．01），与对照相比，2．0％、4．0％和6．0％鸡粪处理土壤微生物生物量碳含量分别增加2．88、5．19、6．98倍，土壤微生物生物量碳（SMBC）含量和土壤微生物商（SMQ）都与鸡粪的添加量呈正相关（rSMBC=0．998^＊＊，rSMQ=0．858，n=12）。在培养过程中士壤微生物生物量碳与土壤微生物商都呈现先下降再升高再下降的趋势。在培养试验的早期，鸡粪的添加有利于缓解铜污染土壤微生物生物量碳的下降，添加鸡粪的处理在培养的第10d后土壤微生物生物量碳含量开始上升，而对照则在30d以后才开始上升；添加鸡粪的处理在培养前期微生物生物量碳的最大下降幅度分别为：2．0％处理（52．74％）、4．0％处理（45．92％）、6．0％处理（55．52％），而对照的下降幅度为92．02％。培养后期添加鸡粪处理土壤微生物生物量碳仍保持较高的水平。

A laboratory aerobic incubation test was conducted under constant temperature to study the effect of 2.0%, 4.0%, 6.0% amounts of chicken manure application on the soil microbial biomass carbon（SMBC） of the soil contaminated by copper. The results showed that the contents of soil organic carbon were improved by 0.85, 1.49, 2.04 times while the soil extractable extracellular carbon（EEC） contents were improved by 3.13, 2.70, 8.23 times after treated by 2.0%, 4.0% and 6.0% chicken manure. The chicken manure promoted the soil extractable extracellular carbon contents,which exhibited a positive correlation with the amount of chicken manure （r=0.994^＊＊, n= 12）. With the prolonged period of incubation, the soil organic carbon and extractable extracellular carbon contents declined in each treatment. The soil organic carbon content became stable after 90 d, whereas the soil extractable extracellular carbon content levelled off at 120d. Moreover, the contents of soil microbial biomass carbon and microbial quotient（SMQ） were also promoted remarkably by chicken manure application （P〈0.01）, with SMBC 2.88, 5.19, 6.98 times higher under 2.0%, 4.0% and 6.0% chicken manure application conditions. Both the contents of SMBC and SMQ played a positive correlation with the chicken manure application amounts （rSMBC=0.998^＊＊, rSMQ=0.858, n=12）. SMBC and SMQ were decreased first, and then increased, but finally declined again during the incubation period. In the early stage of the incubation, chicken manure released the decrease of SMBC. SMBC in chicken manure treatment increased after 10 d, while the CK increased after 30 d. The maximum decreases were 2.0%（52.74%）, 4.0%（45.92%） and 6.0%（55.52%）, while the decrease of CK was 92.02%. The contents of SMBC maintained at a relatively high level in the late stage of incubation with chicken manure application.