ABSTRACT Natural phosphate rocks (PR) are characterized by low phosphorus (P) solubility in water. Acidulation is the normal method to raise P solubility of these materials, however, it increases the cost and causes operational issues. The aim of this study was to evaluate the agronomic efficiency of partially acidulated and micro-granulated Arraias phosphate rock, which has a lower P content (6.88 %) than normal apatite concentrates. Two experiments were carried out in a greenhouse at the University of Rio Verde, […]

The use of stabilized N sources, with mechanisms for inhibition of urease enzyme and with ammonium nitrification inhibitors, may help to achieve higher grain yields, contributing to the sustainability of agricultural activity. The aim of this study was to evaluate the effect of different mineral N sources and application rates on maize grain yield and N use efficiency. A field experiment was carried out in Lages, SC, Brazil, in a randomized block design in split-plots. Nitrogen was side-dressed in the […]

The use of potassium (K) rock powder can be an alternative for K supply of crops. Thus, to reduce K fertilizer imports from abroad, possibilities of extracting this nutrient from Brazilian rocks are being studied. The objective was to evaluate the effect of phonolite rock powder (F2) as K source (Ekosil®) on the air-dried fruit yield, nutrition and macronutrient export of Arabica coffee. The experiment was carried out on a dystroferric Red Latosol (Typic Haplorthox), in Piraju, São Paulo State, […]