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残茬覆盖可提高土壤质量,防止土壤侵蚀,免耕及化学除草可提高残茬盖度。美国学者S.D.Merrill等人在免耕条件下,调查10种作物连续种植2 a,研究不同作物轮作对残茬盖度的影响。结果表明:在春小麦茬上播种10种作物的残茬盖度为62%~97%,其它作物茬上播种10种作物的残茬盖度为35%~86%,向日葵、豌豆及旱豆的残茬盖度35%~48%。利用修订的通用土壤流失模型(RUSLE)预测水蚀,修订的风蚀模型(RWEQ)预测风蚀,然后计算土壤侵蚀速率(SLE)。向日葵连作残茬盖度为35%时,水蚀速率为0.29,风蚀速率为0.21。对侵蚀较严重的土壤,采用免耕技术,当茬覆盖低时,当年播种残茬盖度较高的谷类作物可减少土壤侵蚀。
Stubble coverage can improve soil quality, prevent soil erosion, no-tillage and chemical weeding can improve the stubble coverage. American scholar S.D.Merrill et al investigated no-till conditions, the 10 kinds of crops were planted continuously for 2 years to study the effect of crop rotation on stubble coverage. The results showed that the coverage of stubble on spring wheat stubble was 62% -97%, the stubble coverage of other 10 crops was 35% -86%, and that of sunflower, pea and dry bean Stubble cover 35% to 48%. Water erosion was predicted using the revised Universal Soil Loss Model (RUSLE), a revised wind erosion model (RWEQ) to predict wind erosion, and soil erosion rate (SLE) was then calculated. Sunflower continuous crop stubble coverage of 35%, the water erosion rate of 0.29, wind erosion rate of 0.21. For the more eroded soil, the no-till technology is adopted. When the stubble coverage is low, the cereal crops with the higher stubble coverage can reduce the soil erosion.