“烧苗”多发生在沙质土壤上,因为沙质土壤一般吸收水肥的容量小,保肥能力差。如果化肥施用不当,会使土壤溶液的浓度和PH值急剧变化,从而产生“烧苗”的恶果。这是咋回事呢?得先从植物细胞的构造说起。细胞壁包在原生质的外面,呈半透明的膜状。它既能让水分通过,也能止溶于水里的物质通过。原生质由原生质膜、中 “Burning seedlings” occurred in sandy soil, sandy soil generally absorb water and fertilizer capacity is small, poor fattening ability. If the improper application of fertilizers, will make the concentration of soil solution and the rapid change of PH value, resulting in “burn seedlings” the consequences. What is this? Let’s start with the construction of plant cells. Cell wall wrapped in the protoplasm outside, was translucent membrane. It allows water to pass through, but also to stop the water soluble material through. Protoplasm from the plasma membrane, in