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美国南部大平原旱作制中作物的产量主要受水分的限制。为提高对作物生产的土壤水分供应,必需增加非生长季的总贮水效率和控制土表与植株的蒸发蒸腾(ET)的比例。土壤休闲期采用留茬管理,可使贮水量增加35～75毫米,有效地提高了作物生长的可利用水总量。在得克萨斯的Bushland地区,ET每增加1毫米的有效水,可使粒用高粱增产15.5公斤/公顷(Stewart,1986)。
The production of crops in the drylands of the Great Plains in the southern United States is mainly limited by the moisture content. In order to increase the supply of soil moisture to crop production, it is necessary to increase the total water storage efficiency in the non-growing season and to control the ratio of soil surface-to-plant evapotranspiration (ET). Soil stubble management during leisure, can increase the water storage capacity of 35 to 75 mm, effectively increasing the total amount of available water crop growth. In the Bushland area of Texas, an increase of 1 millimeter of available water per ET results in 15.5 kg / ha of grain sorghum (Stewart, 1986).