长期施用畜禽粪便对土壤生物化学质量指标的影响

采用两种母质发育的,长期施用畜禽粪便和化肥的稻麦轮作土壤作为供试土壤,探讨了施用畜禽粪便对土壤微生物组成、微生物生物量及活性、土壤酶活性等生物化学质量指标的影响。研究结果显示,与施用化肥比较,长期施用畜禽粪便显著提高了土壤细菌和放线菌数量(+72%和+132%)、土壤微生物生物量碳、氮(+89%和+74%)、土壤基础呼吸速率和微生物商(+49%和+45%),但降低了土壤真菌的数量(-38%)。土壤脲酶和转化酶活性也表现为长期施用畜禽粪便土壤高于施用化肥土壤。由于受土壤pH值强烈影响,土壤微生物代谢商(qCO2)和土壤磷酸酶活性没有表现出明显的变化规律。回归分析结果显示,长期施用畜禽粪便改变土壤活性有机碳含量和理化性质是导致土壤生物化学质量指标变化的主要原因。

Effects of long-term application of livestock manures on soil biochemical quality indicators

Application of livestock manure (LM) in field is an impartment way to solve the ecological environmental menace in the intensive and scale development of livestock farming industry. In this paper soils were sampled in five wheat-rice rotation fields on two soil types under long-term application of LM and chemical fertilizer (CF). Biochemical properties, such as soil microorganism composition, microbial biomass C and N (MBC, MBN), soil basal respiration (SBR), soil phosphatase, urease and invertase activities, were investigated as soil biochemical quality indicators. The results showed that, compared with CF treatment, the amounts of bacteria and actnomycete (+72%, +132%), the contents of MBC and MBN (+89%, +74%), the SBR and soil microbal quotient (+49%, +45%) increased significantly but the amount of fungi (-38%) significantly decreased in long-term application of LM treatment. The activities of soil urease and invertase were also higher in long-term application of LM than CF treatment. As greatly affected by pH values, soil microbial metabolic quotient (qCO2) and soil phosphatase changed indistinctly. Successive regression analysis indicated that the changes in soil active organic carbon content and physical and chemical properties are the main reasons for the changes in soil biochemical quality indicator in long-term application of LM.