Termopotassium and phonolite as alternative sources for the fertilization of pastures

Abstract

The Brazilian external dependence for potassium fertilizers and the demand for K sources
applicable to organic and agroecological production stimulates research in search of alternative
sources of fertilizers, this work aimed to evaluate the effect of alternative sources of
K on soil chemical characteristics and on Productivity and nutrition of brachiaria grass. The
experiment was conducted in a factorial scheme (3 x 2) + 3, with three potassium sources (potassium
chloride, thermopotassium and phonolite powder), two K doses and three additional
treatments. The sources affected positively the dry matter production of the brachiaria grass
and were effective in the release of K and Si. In general, for the period evaluated the release
of nutrients by thermopotassium was superior to the phonolite powder and lower than the KCl.
The alternative sources tested were promising considering the application in a single dose.