连续14年黑土坡耕地秸秆覆盖免耕水土保持效应

Effects of Straw Mulching and No Tillage for Continuous 14 Years on Soil and Water Conservation in Mollisols Sloping Farmland

为探究长期秸秆覆盖免耕对黑土坡耕地土壤结构的影响以及水土保持效应,通过秸秆覆盖免耕(NT)和传统顺坡耕作(CT)2组长期定位田间试验,对土壤结构、土壤保水能力、保土效应作对比分析。结果表明:NT与CT相应性状比较,土壤容重没有显著增加(P>0.05),在0—20 cm土层,虽总孔隙度和非毛管孔隙度低,但增加了土壤毛管孔隙度和水稳性大团聚体(WR_(0.25))含量,WR_(0.25)含量和平均重量直径(MWD)差异均达到显著水平(P<0.05);分别提高了垄台土壤初始入渗和稳定入渗速率28.8%,24.7%;0—10 cm土层,饱和含水量和田间持水量差异均达到显著水平(P<0.05);减少了产流次数、径流量和土壤流失量分别为11次,86.6%和98.9%,有效地遏制了水土流失。研究结果表明,长期连续秸秆覆盖免耕是一项有利于土壤结构稳定和遏制土壤侵蚀的黑土地保护措施。

To reveal the influence of long-term straw mulching and no tillage(NT)on soil structure and soil and water conservation of Mollisols sloping farmland,two 14 years long-term experiments,including NT and conventional tillage(CT),were conducted to compare soil structure,water conservation capacity and soil retention effect.The results showed that compared with CT,the soil bulk density of NT did not increased significantly(P>0.05).The total porosity and non-capillary porosity of NT were lower than those of CT in 0-20 cm layer,while NT increased the capillary porosity and content of water stable aggregate(WR_(0.25)),and the differences in WR_(0.25) and mean weight diameter of soil aggregate(MWD)between the two treatments were significant(P<0.05).Meanwhile,NT increased the initial infiltration rate and stable infiltration rate of ridge platform by 28.8% and 24.7%,respectively.And in 0-10 cm layer,the differences in saturated water content and field capacity between the two treatments were significant(P<0.05).In addition,the number of runoff production,runoff and soil loss decreased by 11 times,86.6% and 98.9% in NT,respectively.This study indicated that long-term continuous NT was an effective practice to stabilize soil structure and prevent soil erosion in Molliosls.