农田水利的基本任务之一,就是在于调节和改变农田水利状况,使土壤具有良好的水、肥、气、热条件,满足作物的生长要求。农田水分状况系指农田地面水、土壤水、地下水的多少及其在时间上的变化。当农田水分不足时,就出现“干旱”现象;当农田水分过多时,就造成“涝渍”现象。这两种现象对农业生产都不利,需要采取相应的灌溉或排水措施加以防止。这一讲着重谈 One of the basic tasks of farmland water conservancy is to regulate and change the condition of farmland and water conservancy so that the soil has good water, fertilizer, gas and heat conditions and meet the requirements of crop growth. Farmland moisture status refers to farmland surface water, soil water, groundwater and the number of changes over time. When farmland water is insufficient, “drought” occurs; when the farmland is too wet, “waterlogging” is caused. Both of these phenomena are detrimental to agricultural production and need to be prevented by appropriate irrigation or drainage measures. This talk focuses on