秸秆覆盖对黑土区侵蚀沟植被恢复和固土的作用

Effects of Straw Mulching on Vegetation Restoration and Soil Loss Control on Eroded Gullies in Black Soil Area

[目的]评估东北黑土区秸秆覆盖技术对侵蚀沟的防护作用,旨在为该区侵蚀沟植被恢复、水土流失防治提供数据支撑.[方法]通过野外试验,观测了秸秆覆盖和无秸秆覆盖条件下侵蚀沟不同坡向土壤水热状况、苜蓿生长状况和水土流失状况的变化.[结果]①秸秆覆盖能够显著改善侵蚀沟土壤水热状况,即提高土壤水分含量,降低14:00土壤温度,阴坡秸秆覆盖提高土壤含水量1.8%~6.8%,阳坡秸秆覆盖提高土壤含水量1.1%~4.0%,阴坡秸秆覆盖降低14:00土温0.6~3.1℃,阳坡降低14:00土温0.9~3.6℃;②秸秆覆盖显著改善了侵蚀沟不同坡向苜蓿的生长及生物量积累状况,有利于侵蚀沟岸植被恢复;③秸秆覆盖可有效拦蓄径流、减少泥沙侵蚀量,全年平均保水率为57.34%,全年平均保沙率为67.60%.[结论]秸秆覆盖是一种有效的侵蚀沟治理措施,该技术的推广将有助于减缓黑土区水土流失,保障国家粮食全.

[Objective]The impacts of straw mulching technology on the gully erosion in black soil area were evaluated in order to provide reference for vegetation restoration and soil erosion prevention.[Methods]Field experiments were conducted to observe the variations in soil hydrothermal conditions,alfalfa growth,and soil as well as water loss in two slope aspects of gully banks under the presence and absence of straw mulch.[Results]①Straw mulching was observed to significantly improve the soil water and heat conditions in the gully.Straw mulching on the shady and sunny slopes increased the soil moisture by 1.8%—6.8%and 1.1%—4.0%,respectively,and reduced the soil temperature at 14:00 by 0.6—3.1℃and 0.9—3.6℃,respectively.②Further,the straw mulching evidently improved the growth and biomass accumulation of alfalfa in two slope aspects of the gully banks,which was conducive to the vegetation restoration of gully banks.③Straw mulch could also effectively reduce soil erosion on the gully banks.The annual average runoff and sediments reduction rates were 57.34%and 67.60%,respectively.[Conclusion]The results obtained indicate that straw mulching is an effective measure for the control of gully erosion;consequently,the promotion of this technology will facilitate the reduction in the soil and water loss in the black soil area,which will ensure the food security of the country.