玉米是一种植株高大,根系发达,生长期较短的作物。据研究,夏玉米每生产100斤籽粒,分别需要氮4.4斤(按纯氮计算,下同),磷1斤,钾3.5斤,每生产1斤籽粒,约需水1,000斤。可见,夏玉米是喜肥喜水的作物。但并不是肥水多就可以高产,更不是愈多愈好,而是重在及时、合理。一、苗期玉米出苗后,由于苗小,叶片小而少,蒸腾量小,单株需要水分不多。如果播种时土壤已有足够的水分,通常可以不浇水,以使地上部与地下部协调生长,有利于抗倒。有些地方水、肥条件好,且实行深播浅盖,不容易倒伏,苗期水分多些也可以,但不宜太多,否则土壤通气不良,缺少氧气,造成根系窒 Corn is a tall, rooted and short-lived crop. According to the study, each 100 kg of kernel corn produced, respectively, need nitrogen 4.4 kg (calculated according to pure nitrogen, the same below), phosphorus 1 kg, potassium 3.5 kg, each producing 1 kg of grain, about 1,000 pounds of water. Visible, summer corn is hi hi hi water crops. But not too much fertilizer can be high yield, but not the more the better, but the emphasis on timely and reasonable. First, the seedling emergence of corn, due to seedling small, small and small leaves, transpiration is small, the plant needs less water. If the soil has enough water when sowing, it is usually not watering, in order to make the aboveground and underground coordination grow, is conducive to anti-down. In some places, water and fertilizer conditions are good, and deep shallow cover is applied, which is not easy to lodging. There is more water in the seedling stage, but not too much water, otherwise the soil will be badly ventilated and lack of oxygen, causing the root system to stifle