EVALUATION OF PHONOLITE ROCK AS AN ALTERNATIVE POTASSIUM FERTILIZER

What is it about?

Alternative sources of inorganic fertilizer are being studied mainly in relation to potassium. The reactivity of rocks and therefore the K+ availability can be changed by modifications in the mineral structure. Stonemeal is an alternative agricultural practice that helps to rehabilitate poor soils and renew the fertilization of farm areas through the incorporation of ground rocks into the soil. In this context, the objective of this work is to evaluate the physical and chemical characteristics of the phonolite rock, from the Poços de Caldas Plateau, MG, according to the parameters for evaluation of potassium fertilizers. The phonolite rock has about 9% of K2O, in addition to other nutrients that are also required by plants, such as Mn, Ca, and Fe. The main minerals that make up the rock, identified by XRD, are microcline and orthoclase, confirming that its main mineralogy is formed by potassium feldspar minerals. All the samples were characterized by XRD, FTIR, and SEM/EDS, and K+ availability was investigated in 0.01 mol L−1 citric acid solution. Results showed that thermal treatment promotes K+ and Na+ availability due to changes in mineral structures. Thermal treatment of phonolite rock at 600 and 1200 °C increases the K+ availability. The results indicate that the phonolite rock has potential for application in agriculture as an alternative input of potassium.

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Photo by Etienne Girardet on Unsplash

Photo by Etienne Girardet on Unsplash

Why is it important?

The results indicate that the phonolite rock has potential for application in agriculture as an alternative POTASSIUM FERTILIZER.