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在蔬菜生产中,肥害有以下两种类型。外伤型:①气体伤害。主要是氨气挥发于空气中引起。当氨气浓度在5ppm 以上时,植物叶片呈水渍状斑,细胞失水死亡之后,留有枯死病斑;当浓度达40ppm 时,则发生急性伤。症状是叶绿素被解体,叶脉间有点(块)状褐黑色伤斑出现。在施用碳酸氢铵、氨水时最易发生气体伤害,土壤干燥情况下使用尿素也常发生。②浓度过高引起的毒害。如一次施人畜粪尿量过大,土壤溶液浓度增大,作物对养分和水分的吸收受阻,导致细胞渗阻力增
In vegetable production, fertilizer has the following two types. Trauma type: ① gas injury. Mainly caused by ammonia volatilization in the air. When the concentration of ammonia is above 5ppm, the leaves of plants are water-stain-like spots, leaving dead spots after dehydration of cells; when the concentration reaches 40ppm, acute injury occurs. Symptoms of chlorophyll were disintegrated, a little (block) brown black spots appear between the veins. In the application of ammonium bicarbonate, ammonia most prone to gas injury, the use of urea in dry soil often occur. ② concentration caused by poisoning. If once applied livestock excrement is too large, the concentration of soil solution increases, crop absorption of nutrients and moisture blocked, resulting in increased cell resistance