不同有机物料施用对砖红壤团聚体组成和稳定性的影响

Effects of Different Organic Material Application on Aggregate Composition and Stabilityof Latosol

通过培养和盆栽试验,研究猪粪、鸡粪、甘蔗叶、稻秆、稻秆生物炭等不同有机物料及其混施对砖红壤团聚体组成特征的影响,并利用团聚体平均重量直径(MWD)、几何平均直径(GMD)、分形维数(D)等指标和主成分分析方法(PCA)评价了土壤团聚体的稳定性特征。结果表明:与对照相比,施用有机物料,使土壤>1mm机械稳定团聚体比例提高了2.3%~45.7%,单施鸡粪效果最显著;使>0.5 mm水稳性团聚体比例提高了3.0%~41.4%,鸡粪+稻秆生物炭混施效果最显著。单施鸡粪对团聚体机械稳定性提升效果最好,团聚体MWD和GMD分别提高了36.3%和28.3%;鸡粪与稻秆生物炭混施对团聚体水稳性提升效果最好,团聚体MWD和GMD分别提高了32.1%和27.7%。>2mm团聚体比例分别与机械稳定性和水稳性团聚体MWD、GMD呈极显著正相关,与团聚体D值呈显著负相关,表明>2 mm团聚体对提高砖红壤结构稳定性具有积极意义。综合主成分分析和差异显著性分析结果,可得出鸡粪与稻秆生物炭混施提高砖红壤团聚体稳定性效果最佳的结论。

The effects of pig manure,chicken manure,sugarcane leaf,rice straw,rice straw biochar and their combination application on aggregate composition of latosol were studied by soil culture and pot experiment,and mean weight diameter(MWD),geometric mean diameter(GMD),fractal dimension(D)of aggregate,and the principal component analysis(PCA)method were used to evaluate the aggregate stability.The results showed that compared with the control,organic material application increased the proportion of>1 mm mechanical-stable aggregates by 2.3%to45.7%,and the effect of single application of chicken manure was the most significant;the percentage of>0.5 mm water-stable aggregates increased by 3.0%to 41.4%,and the effect of chicken manure+rice straw biochar was the most significant.The application of chicken manure had the best effect on improving mechanical stability of aggregates with its MWD and GMD increased by 36.3%and 28.3%respectively;the mixed application of chicken manure and rice straw biochar had the best effect on improving water stability of aggregates with its MWD and GMD increased by32.1%and 27.7%respectively.The MWD,GMD of mechanical and water-stable aggregate and the proportion of>2 mm aggregates were significantly positively correlated,indicating that>2 mm aggregates had positive significance for improving the structural stability of latosol.Comprehensive results of principal component analysis and difference significance test indicated that mixed application of chicken manure and rice straw biochar had the best effect on improving aggregate stability of Latosol.