摘要
为揭示不同覆盖耕作模式对黑土区坡耕地土壤侵蚀防治及水分利用效率的影响机制,设置顺坡免耕碎秆均匀覆盖(SM)、顺坡免耕覆盖作物(SC)、横坡免耕碎秆均匀覆盖(CM)和传统耕作(CK)4种覆盖耕作模式,研究分析黑土区坡耕地土壤水分动态变化规律,明确不同覆盖耕作模式的土壤侵蚀特征,分析不同覆盖耕作模式对水分利用效率的影响.结果表明:顺坡免耕碎秆均匀覆盖(SM)、顺坡免耕覆盖作物(SC)和横坡免耕碎秆均匀覆盖(CM)均能不同程度地增加土壤水分含量,防治土壤侵蚀和提高水分利用效率.SM处理、SC处理与CM处理较CK处理0～80 cm 不同土层土壤含水率分别提高 9.34％～18.20％,5.30％～11.54％和 9.12％～19.84％;径流量、侵蚀量、降雨量和最大30 min雨强(I30)均与水分利用效率呈显著负相关性;SM处理、SC处理和CM处理的水分利用效率较CK处理均有提高,其增幅介于1.18％～10.76％.通过对比分析减流减蚀效果和水分利用效率,发现在防治土壤侵蚀,蓄水保墒及提高水分利用效率方面,横坡免耕碎秆均匀覆盖模式效果更好.
Abstract
To reveal the influence mechanism of different cover cropping modes on soil erosion control and water use efficiency of sloping cropland in the black soil zone,four cover cropping modes were set up,namely,no-till chopped straw uniform cover downhill(SM),no-till cover crop downhill(SC),no-till chopped pole uniform cover across the slope(CM),and conventional tillage(CK).The soil moisture dynamics of sloping arable land in the black soil zone,its water retention and soil fixation ca-pacity as well as its water use efficiency were researched and analyzed.The results show that no-till chopped straw uniform cover downhill(SM),no-till cover crop downhill(SC),and no-till chopped pole uniform cover across the slope(CM)have different degrees of effects on increasing soil moisture content,preventing soil erosion,and improving water utilization efficiency.The average soil water con-tent of 0-80 cm different soil layers increases by 9.34％-18.20％,5.30％-11.54％and 9.12％-19.84％in SM,SC and CM treatments,respectively,compared with that of CK treatment during the whole crop life.Runoff,erosion,rainfall,and maximum 30 min rainfall intensity altogether significantly negatively correlates with water use efficiency.SM,SC and CM treatments improve water use efficiency by 1.18％-10.76％compared to CK treatment.By setting up four different mulching till-age modes,revealing the changing law of soil moisture under different mulching tillage modes,clarif-ying the soil erosion characteristics of different mulching tillage modes,and analyzing the effects of dif-ferent mulching tillage modes on the water use efficiency,it is concluded that the no-till chopped pole uniform cover across the slope mode is the most effective in preventing soil erosion,storing and conser-ving moisture and improving water use efficiency.
基金项目
国家重点研发计划项目(2021YFD1500802-2)
国家自然科学基金资助项目(52079030)
国家科技期刊平台
NSTL
万方数据