黄土旱塬农田全程全覆盖的“土壤水库”作用

Effec of Soil Reservoir of Full Cover During Whole Course on Loess Dry Farming

晋南黄土旱塬虽土层深厚 ,蓄水、保水性能良好 ,但传统农业的农田“土壤水库”作用有限 ,在年降水量较小且分布不均匀 ,而蒸发量较大的情况下 ,天然降水利用率很低 ,作物产量极不稳定。为寻求解决这一问题的有效途径 ,于 1991～ 1996年进行了 6年的探索 ,研究出在旱地农田实行全程全覆盖的保水措施 ,采用不同覆盖材料 ,配合垄作方式 ,既能较大程度地吸纳天然降水 ,又可做到全程全封闭地抑制土壤水分蒸发 ,形成良好的“土壤水库”,使不均衡的天然降水变为较均匀的供水 ,在整个覆盖周期内其土壤贮水量始终高于半覆盖和不覆盖处理 ,有效地缓解了作物旱情 ,提高了天然降水的利用效率。

The soil layer is proundity, and its sluice capability is a ll right on the loess of Jinnan, but there is a little precipitatio n and a great deal of transpiration in the dry farming. T he effect of “soil reservoir” was finity and the precipitation using rate was low in the tradition agriculture. In order to seek the availability means to solve this problem, the test was carried for 6 years, and the manner that two kinds of material was c overed and the ridge was built in the field during the whole course was found. The manner is able to accept more precipitation and contr ol the soil moisture transpiration fully and form “the soil reservoir ”. The precipitation was become the water-supplying evenly, and the soi l pondage was increased. The using efficiency of precipitation was imp roved.