秸秆不同还田方式对土壤入渗特性及持水能力的影响

通过入渗试验及对土壤水分特征曲线的测定，对比研究了秸秆在经过粉碎、氨化及与无机土壤改良剂混合3种措施处理后加入土壤中对土壤入渗特性及持水特征的影响。结果显示：长秸秆处理加入土壤后显著降低土壤入渗能力；粉碎氨化后的秸秆较对照处理及粉碎秸秆处理能显著增加土壤稳定入渗率、土壤累积入渗量，同时在经过30 d培养后土壤体积质量较对照低7.13%；无机土壤改良剂（氢氧化铁）能显著提高土壤稳定入渗率和累积入渗量，但在减小土壤体积质量、增加土壤孔隙度作用方面不如氨化秸秆处理显著，同时当秸秆与其混合加入土壤时未对土壤改良效果起到正交互作用；各种处理土壤持水能力差异不明显，但粉碎并氨化措施处理过的秸秆在中低吸力段均表现出较高的土壤持水能力，这对于提高旱区农田蓄水保墒抗旱能力有重要意义。

Effect of straw-incorporation on soil infiltration characteristicsand soil water holding capacity

Soil infiltration process and soil water retention curve were determined for soils incorporated with wheat straws in different manners, i.e. comminuted, aminated or blended with inorganic soil amendment, and their effects on soil infiltration characteristics, soil water retention capacity were compared and analyzed. Results showed that long straw could decrease soil infiltration apparently. Straws comminuted and aminated were better than that of control and the comminuted straw at raising stable infiltration rate and cumulative infiltration, while its bulk density after 30 days of incubation was smaller by 7.13% than that of control. The inorganic soil amendment could considerably increase stable infiltration rate and cumulative infiltration. However, its effects on decreasing soil bulk density and raising the overall porosity were not greater than that of straw comminuted and aminated. The straw and inorganic soil amendment tended not to play a positive interaction when they were used together. The difference of the soil water holding capacity of all the treatments was indistinctively. However, the finely comminuted straw could keep higher water holding capacity