Silicon in the Soil As a Result of No-Tillage Steel Slag Application.

In the literature there are several reports concerning silicon increase due to steel slag use, however, its composition may vary in silicon according to its production. Thus, the objective of the present study was to assess the availability of silicon in the soil and in the crops bean, oat and soybean according to the types of slags applied in no- tillage system. The experiment was carried out in the field at São Paulo State University - UNESP in Botucatu, Brazil. The treatments consisted of two application methods (incorporated and surface) of limestone, wollastonite and five slags: steel slag 1 and 2; blast furnace slag; stainless steel slag (agrocilicate), and a control without application. The dose applied of each material was calculated to raise the V% to 70. Soil was sampled and analyzed for soluble Si after 2 and 12 months of silicate reactions. The application methods were not different in soil silicon availability and in the plants. Similar behavior was observed in all depths with higher Si content after 2 months of silicate reactions when agrosilicate, steel slag1 and steel slag2 were applied. The soil silicon increased with the period of incubation, maintaining the results obtained in the 2 months with higher Si content with agrosilicate, steel slag1 and steel slag2 in the deeps 0-5 and 5-10 cm. The slag 2 was the material with the higher silicon content, 21,6% of total silicon, what explain the results obtained. Silicates increased Si in plant tissue bean, mainly with Agrosilicate and Wollastonite application.