秦岭中段北麓农耕地秸秆还田对土壤团聚体及可蚀性季节性变化的影响
Effects of Straw Returning on Soil Aggregate and Seasonal Variation in Soil Erodibilityfor Agricultural Area in the Northern of the Middle of Qinling Mountains
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摘要: 选取秦岭中段北麓陕西关中地区典型农业土壤塿土, 添加小麦、大豆、玉米秸秆, 并选择无秸秆添加作为对照。秸秆混入375 d, 共采集样品11次, 探究秸秆混入对团聚体特征及可蚀性季节性变化的影响。结果表明: (1)土壤有机质呈现明显的季节性变化, 随着秸秆混入时间的延长, 土壤有机质含量呈上升趋势; 与混入前相比, 实验结束时添加小麦、大豆、玉米秸秆的处理有机质含量分别提高了19.56%、18.28%、18.61%。(2)秸秆混入降低了小于1 mm团聚体比例, 增加了大于1 mm团聚体占比; 与混入前相比, 实验结束时添加小麦、大豆和玉米秸秆三种处理的平均重量直径(MWD)分别提高了67.31%、68.53%、56.98%, 几何平均直径(GMD)分别提高了45.77%、35.00%、40.25%。(3)与裸地相比, 混入秸秆样地的土壤可蚀性值均显著降低, 添加小麦、大豆、玉米秸秆处理的土壤可蚀性平均值分别降低了28.92%、23.33%、26.40%。研究结果探明了秸秆混入对土壤团聚体特征和土壤可蚀性的季节性变化的影响, 对我国南北过渡带水土流失区农业生产实践具有重要的参考价值。Abstract: A typical agricultural small soil in the mid-northern foothills of the Qinling mountains-Guanzhong region of Shaanxi province was selected with wheat, soybean and maize straw additions and no straw addition as a control. Samples were collected 11 times over 375 days to investigate the effects of straw addition on seasonal changes in agglomerate properties and erodibility. The results showed that: (1) The soil organic matter showed obvious seasonal changes, with the extension of the time of straw mixing, the soil organic matter content showed an upward trend; compared with the pre-mixing, the organic matter content of the treatments with wheat, soybean and maize straw added at the end of the experiment increased by 19.56%, 18.28% and 18.61%,
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