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通过在黄土坡面上实施鱼鳞坑整地的自然化造林试验,对1 m深土壤剖面的水分季节变化进行了测定和分析,探讨了鱼鳞坑整地在黄土区植被重建中的应用。结果表明:鱼鳞坑的雨季蓄水过程明显,阳坡坑春季较原状荒坡的含水量增幅均值可达18.18%,其改善土壤水分状况的程度高于阴坡坑(增幅均值9.93%);季节更替中,阴坡坑的土壤含水量(剖面均值11.46%~22.26%)始终高于阳坡坑(剖面均值8.90%~19.12%),早春阴坡坑中可见冬季上层土壤含水量的上升;土壤水分受气候的深刻影响,变异系数及反映蒸发的降幅表层大于深层,阳坡坑(剖面均值变异系数25.85%、降幅34.10%)高于阴坡坑(剖面均值变异系数18.73%、降幅21.10%);阳坡坑中覆膜(剖面水分均值10.62%~19.27%),虽不及阴坡自然力,但可显著缓和阳坡干燥气候的影响(剖面均值变异系数20.89%、降幅29.54%),有助于调用深层水分,尤其在旱季末可较好地延缓土壤含水量的急剧下降。黄土区植被重建重视鱼鳞坑整地的同时,采取抑蒸保墒、限量灌水的辅助措施是必要的,但应注意其使用时间;南部的阴坡种植,可不整地或改用穴状整地形式;春季种植适宜尽早进行。
Through the natural afforestation experiment on the loess slope, the seasonal changes of water content in 1 m deep soil profile were measured and analyzed, and the application of fish scale pit site preparation in the vegetation reconstruction of the loess area was discussed. The results show that the rainwater storage process of fish scale pit is obvious. The average water content of sunny slope in spring slope is up to 18.18% compared with that of the original slope, and its degree of improving soil moisture is higher than shady pit (average increase 9.93%). In the replacement, the soil moisture content of shady pit (average section of 11.46% ~ 22.26%) was always higher than that of sunny slope pit (section average 8.90% ~ 19.12%). In early shady pit, the upper soil moisture content increased in winter; Moisture is affected by the climate. The coefficient of variation and the declining surface layer reflecting the evaporation are larger than the deep layer. The sunny slope pit (mean variation coefficient of 25.85% and 34.10% of the average value of the profile) is higher than the shady slope pit (average variation coefficient of the profile is 18.73% and the decrease rate is 21.10%). (Averaged 10.62% -19.27% of the average water cut in the slope), though not as good as the natural force of the shady slope, can significantly reduce the impact of dry climate on the sunny slope (average coefficient of variation of 20.89% and 29.54% decrease) Calling deep water, especially at the end of the dry season, can well delay the drastic drop in soil moisture content. At the same time of rebuilding the loess area, emphasis should be put on the site preparation for fish-scale pit excavation. At the same time, it is necessary to take the measures of restraining steaming soil moisture and limiting the amount of irrigation. However, it should be paid attention to the time of its use. In the southern shady planting, Suitable for early.