太湖地区土壤是属于供硅能力较高的类型,但不同土种有效硅含量并不相同。近几年,我们在太湖地区水稻田进行土壤有效硅含量的测定和施用硅肥的试验,结果如下: (一)太湖地区土壤的有效硅含量 从21个土壤剖面的有效硅含量看出(表1),与水稻生长有关的耕作层的有效硅含量,不同土壤有较大差别。就主要土种来说,有效硅含量次序是:白土<沙性土<乌栅土。 以水稻缺硅的临界值9.5毫克为标准,则白土除极个别外,一般均低于临界值,因此白土是太湖地区主要的缺硅土壤。沙性土的有效硅含量和临界值相近,其供硅能力中等偏低。乌栅土则是硅素供应丰富的土壤。另 Soil in Taihu Lake region belongs to the type with higher silicon supply capacity, but the effective silicon content in different soil types is not the same. In recent years, we measured soil available silicon in paddy fields in Taihu Lake and tested the application of silicon fertilizers. The results are as follows: (1) The effective silicon content of soils in Taihu Lake area is found from the available silicon content of 21 soil profiles 1). The effective silicon content of the tillage layer related to rice growth varies greatly among different soils. For the main soil species, the order of available silicon content is: Clay