甜菜同其他作物一样,不仅用根系吸收土壤养分,而且还能借叶子上的角质层、气孔和细胞,将低浓度的营养液扩展到体内。我们利用这种特性,把低浓度的肥料溶液喷洒到甜菜叶子上,提高光合作用强度,促进甜菜生长。这种施肥方法,叫做根外追肥。一、根外追肥的好处 (一)能充分发挥肥效,避免营养物质损失。肥料施入土壤,容易使一部分营养物质同土壤中的一些物质结合,不能被甜菜根吸收;或者由于土壤微生物的有害作用 Beet, like other crops, uses not only the root system to absorb soil nutrients but also the low concentrations of nutrient solution that can be spread into the body by the stratum corneum, stomata and cells on the leaves. We use this feature to spray low-concentration fertilizer solutions onto beet leaves to increase photosynthesis and promote sugar beet growth. This method of fertilization, called root top dressing. First, the benefits of root top dressing (A) can give full play to fertilizer efficiency, to avoid the loss of nutrients. Fertilizers are applied to the soil, making it easier for some of the nutrients to bind to some of the soil and can not be absorbed by the beetroots; or because of the deleterious effects of soil microorganisms