耕作和施肥扰动下土壤团聚体稳定性影响因素研究

稳定的土壤团聚结构对种子发芽、根系发育、作物生长以及有机碳保护有着重要的影响,深入了解人为扰动下土壤团聚体稳定性影响因素有着重要意义.选择两种不同母质发育土壤上长期施用畜禽粪便和化肥5个田块耕层土壤团聚体为供试土壤,采用相关分析、因子分析和回归分析方法探讨了土壤有机碳库、土壤养分和理化性质与团聚体稳定性间的关系.研究结果表明,与施用化肥比较,施用畜禽粪便显著提高了土壤团聚体稳定性;不同母质类型土壤上,海相沉积物母质土壤上团聚体稳定性显著高于河相冲积物母质土壤.相关分析结果表明溶解性有机碳(包括DOC和HWOC)和总磷含量与土壤团聚体稳定性显著或极显著相关;因子分析结果显示,土壤化学因子是第一影响因素,土壤碳库因子是第二影响因素,其中海相沉积物母质土壤上团聚体稳定性主要受土壤化学因子影响;河相冲积物母质土壤团聚体稳定性主要受土壤碳库因子影响,施用化肥土壤受两个因素影响均较小.回归分析结果显示热水提取态有机碳和钙是本研究条件中影响土壤团聚体稳定性的主要因素.

Influence factors of soil aggregate stability under disturbing of cultivation and fertilization

Stabilized soil aggregate structure determines germination and rooting of cultivated plants and the ability of soil to store carbon through physical protection. Therefore, it is very important for better understanding influence factors of soil aggregate stability under human disturbance. Soil aggregates were sampled in five fields with long-term fertilization of organic manure and chemical fertilizer on two type soils and correlation analysis, factor analysis and regression analysis were applied to study the relationship between soil aggregate stability and soil organic carbon pools, selected soil chemical and physical properties. Results showed that soil aggregate stability significant increased in soils with application organic manure comparing with soils appling chemical fertilizer. Stability index of soil aggregate in soil derived from marine sediment was higher than that in soil derived from fluvial deposit. Result of correlation analysis indicated that there was a significant correlationship between dissolved organic C, hot water extractable organic C(HWOC), total phosphorus and soil aggregate stability. Factor analysis showed that the first influence factor was soil chemical factor(F1), and the second influence factor was soil carbon pool factor(F2). F2 was the dominant factor influencing soil aggregate stability in soil from fluvial deposit marine sediment, while F1 was the main factor influence soil aggregate stability in soil from marine sediment. Results from regression analysis showed HWOC and Ca was the main factors influence soil aggregate stability in this study.