Agronomic Efficiency of Biotite in Soybean and Corn Silage Production

The aim of the present study is to assess the agronomic efficiency and potential of using biotite, a remineralizer, as nutrient source to both soybean (Glycine max (L.) Merrill and maize silage (Zea mays L.). These crops were grown in succession in different soils. The research was conducted due to the importance of adopting alternative sources of fertilizers for agriculture and the relevance of using ground silicate rock powders to maximize plant growth. The purpose was to also register this product in Ministry of Agriculture, Livestock and Supply (MAPA) as a soil remineralizer. Biotite (BE), a silicate rock powder used as soil remineralizer, was provided by Embu Mineral Company, Mogi das Cruzes, São Paulo State, Brazil. BE samples were used for particle size, mineralogical and geochemical analysis in order to assess its classification as a soil remineralizers based on Normative Instruction N. 5/2006, by MAPA. Two experiments, one with each crop, were conducted on a sandy loam texture Yellow Latosol (LA) and a clay Red Latosol (LV) soil. The experiments were zed block design with four replicates. Treatments consisted, witness, biotite (BE) remineralizer at four increasing K2O rates (30, 60, 120 and 240 kg K2O ha-1), KCl at 60 kg K2O ha-1, and FMX remineralizer (fine-graded mica schist from Pedreira Araguaia Mineral Company). Both KCl and FMX were used as reference K2O sources. Yield data have shown K release in the soil and absorption by the test plants resulted in yield increases. Biotite behavior in the soil is similar to that of FMX and in some cases, to that of KCl. Biotite has great potential to be used as potassium source in soybean and maize crops.