不同外源碳对退化黑土微生物量碳、土壤呼吸量及酶活性的影响

Effects of Different Exogenous Carbon on Soil Respiration,Microbial Biomass Carbon and Enzyme Activity in Degraded Black Soil

为筛选能够提高退化黑土生物肥力的外源碳种类,以红糖、褐煤、腐殖酸钠等外源碳为试材,将不同外源碳设置为5个处理,分别为空白对照(CK)、红糖(T)、褐煤(H)、腐殖酸钠(F)以及红糖+褐煤(TH)进行室内土壤培养试验并运用主成分分析法筛选最优处理。研究了添加不同种类的外源碳对退化黑土的土壤呼吸量、微生物量以及相关酶活性的影响。结果表明:添加4种不同外源碳对土壤呼吸速率与呼吸积累量均有促进作用,培养前期表现为T>TH>F>H>CK,后期T、H、F、CK处理差异不显著;添加4种不同外源碳都可以增加土壤微生物量碳,表现为T>TH>H>F>CK;添加4种不同外源碳对土壤酶活性具有促进作用,随着时间变化,T处理对土壤酶活性的促进效果最强;主成分分析后综合评分排名为T>TH>F>H>CK。因此,添加外源碳能够提高退化黑土微生物活性,提升其生物肥力。4种不同外源碳处理中,T处理效果最好,其次为TH处理。

In order to screen exogenous carbon species that could improved biofertility of degraded black soil,brown sugar,lignite,sodium humate were used in this experiment.Soil incubation experiments were carried out by setting different exogenous carbon into 5 treatments and used PCA（principal component analysis）to screen the best treatment.The treatments include blank control（CK）,sugar（T）,lignite（H）,sodium humate（F）and brown sugar＋lignite（TH）.The effects of different exogenous carbon on soil respiration,microbial biomass carbon and related enzyme activities in degraded black soil werestudied.The results showed that soil respiration rate and respiration accumulation added four different exogenous carbon in incubation earlier stage showed T〉TH〉F〉H〉CK,but laterH,F and T had no significant difference between CK.Soil microbial biomass carbonincreased as T〉TH〉H〉F〉CK by adding four kinds of exogenous carbon.Adding exogenous carbon could promote soil enzyme activities.With time changing,the soil enzyme activities in brown sugar treatment were the strongest.Comprehensive score ranking of principal component analysis showed result for T〉TH〉F〉H〉CK.Therefore,the exogenous carbon would improve degraded blacksoil microbial activity and biological fertility.Effect of brown sugar treatment（T）was the most significant in the four kinds of exogenous carbon treatments,followed by brown sugar＋lignite（TH）treatment.