论文部分内容阅读
一、砂田的功能及其作用。砂田是旱作农业生产的一种主要措施,具有抗旱增产,旱涝有收之功效。它能够有效地拦蓄雨水,减少蒸发,蓄水保墒,提高地温,透水性强尤其具有除碱改良土壤的特殊作用。 1.提高土壤含水量,这是因为:一是砂质疏松无表面流失,降落的雨水可全部接收,并输入土壤中,具有保水作用;二是切断土壤毛细管,减少水分上升蒸发;三是土壤被砂层覆盖不受风吹日哂,水分自然蒸发率降低,保墒性能高,可满足植物对水分的需要;四是土壤的水分蒸发到砂层中便附着在砂粒上,起到了湿润地表的作用。据长期的经验来看,砂田含水量比旱土地高一倍以上。当土地植物生长缺水接近萎蔫下限时,砂地植物仍可维持正常生长;当土地含水量基本维持植
First, the function of sand and its role. Sandy fields are one of the main measures for dry farming. They have the effect of drought-resistant and yield-increasing and have the effects of drought and flood. It can effectively trap rain water, reduce evaporation, water and soil moisture, improve ground temperature, water permeability, especially with the special role of soil improvement in addition to alkali. 1. To improve soil moisture content, this is because: First, there is no surface loss of sandy loose, all the rainfall can be received and input into the soil, with water retention; Second, cut off the soil capillaries to reduce the evaporation of water increases; Third, soil The sand is covered by the wind without sundial, the natural evaporation rate of water decreases, high moisture conservation performance, to meet the plant’s water needs; Fourth, the soil’s water evaporates into the sand layer will be attached to the sand, played a moist surface effect. According to long-term experience, the water content in the sand field is more than double that of the dry land. When the growth of land plants close to wilting water shortage, sand plants can still maintain normal growth; when the basic maintenance of land moisture content of plants