摘要:为研究河西绿洲灌区保护性耕作对土壤风蚀的影响，通过春小麦田间试验，设置免耕不覆盖、免耕秸秆覆盖、立茬和残茬压倒4种保护性耕作处理，以传统耕作为对照，分析了河西绿洲灌区不同保护性耕作措施对田间输沙量、风蚀深度、风蚀物粒径组成、风速的影响。结果表明：0~30 cm高度输沙量能敏感地反映不同耕作措施之间输沙量的差异。与传统耕作相比，免耕不覆盖、免耕秸秆覆盖、立茬和残茬压倒处理0~30 cm高度输沙量分别减少17.4%~46.7%、21.7%~45.2%、24.7%~48.2%和10.7%~42.4%。风蚀深度传统耕作为1.22~1.44 mm，4种保护性耕作处理均为0 mm。与传统耕作相比，保护性耕作处理风蚀物粒径组成无显著变化，但 < 0.063 mm细粒占比有减小趋势。立茬处理20 cm高度风速显著降低24.1%~39.5%，其他保护性耕作措施风速降低不显著。综上所述，河西绿洲灌区不同保护性耕作措施能不同程度地抑制土壤风蚀，立茬处理是相对较优的保护性耕作措施，适宜该地区推广应用。
关键词:保护性耕作/
土壤风蚀/
输沙量/
风蚀深度/
风蚀物/
河西绿洲灌区
Abstract:In arid areas, conservation tillage has the important advantage over conventional tillage reduction of soil erosion. Up to now, there have been few reports on effects of conservation tillage on soil wind erosion in the Hexi oasis irrigational area of China. A spring wheat field experiment was conducted to investigate the effects of different conservation tillage measures on field sediment discharge, wind erosion depth, wind erosion sediment granulometric composition, and wind speed in the Hexi oasis irrigational area, Gansu Province, Northwest China. The conservation tillage measures adopted in this study over three years included no-tillage with no stubble mulching (NT), no-tillage with stubble mulching (NTS), standing stubble (SS), and stubble overwhelm (SO), with conventional tillage (CT) as the control. The results showed that a sediment discharge of 0-30 cm could sensitively reflect the differences in sediment discharge among different tillage measures. Compared with CT, the sediment discharge of 0-30 cm decreased by 17.4%-46.7% in NT, 21.7%-45.2% in NTS, 24.7%-48.2% in SS, and 10.7%-42.4% in SO. The wind erosion depth was 1.22-1.44 mm for conventional tillage, and zero for each conservation tillage. Compared with CT, the wind erosion sediment granulometric composition of conservation tillage was no significant change, but the proportion of size of fine-grained soil (< 0.063 mm) had a decreasing tendency. The wind speed at 20 cm depth was significantly reduced by 24.1%-39.5% in SS and non-significantly reduced under other conservation tillage measures. In summary, different conservation tillage measures can control soil wind erosion to different extent in the Hexi oasis irrigational area; standing stubble was the most optimal conservation tillage measure and proved suitable for application in this area.
Key words:Conservation tillage/
Soil wind erosion/
Sediment discharge/
Wind erosion depth/
Wind erosion sediment/
Hexi oasis irrigational area
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