灌溉的目的在于提高农作物的产量,这种“效应”发生在根系层中。根系层中土壤水、养分、通气和热状况等作物生长的诸要素保持在一个适宜的范围内,才能使作物获得高产。其中土壤水是最活跃最关键的要素,所以农业生产上“有收无收在于水”之说颇为盛传。一切形态的水,只有转变成土壤水,作物才能吸收利用。所幸土壤就象一个水库,能够保持水,以供作物在一定的时 The purpose of irrigation is to increase the crop yield, which “effect” occurs in the root layer. Roots of soil water, nutrients, ventilation and thermal conditions and other crop growth in the various elements of maintaining a suitable range, in order to make the crop yield. Among them, soil water is the most active and the most crucial factor, so that the agricultural production is said to have nothing to do with water. All forms of water, only into soil water, crops can be absorbed. Fortunately, the soil is like a reservoir, able to keep water for crops at a certain time