Eficiência agronômica de fontes alternativas de potássiona na cultura do milheto

Abstract

Potassium is an essential nutrient for plant growth and development, playing a crucial role in crop quality and productivity. However, the extraction and production of potassium chloride, the main commercial source of this element, has significant environmental impacts and future availability concerns. The search for new sources of potassium is necessary given the high external dependence on fertilizers containing this element. With the aim of evaluating the use of alternative sources of potassium, experiments were carried out with millet (Pennisetum glaucum), cultivar ADR-300, in a greenhouse, using samples from 4 soils with different textures, (Sandy, Medium, Clayey, Very Clayey), in two consecutive cultivations using 11 ground rocks rich in potassium at doses of 600 mg of K2O dm-3 of soil. For comparison, a treatment with KCl was used as a standard fertilizer and an absolute control without added potassium. The remaining nutrients were supplied in sufficient quantities to meet the crop’s needs. The experiment was conducted in a completely randomized design with 13 treatments, and the data were subjected to analysis of variance and the means compared by the Scott - Knott test at 0.05 significance and the agronomic efficiency index compared by the Dunnett method. The variables analyzed at the end of the experiment: dry matter of the millet aerial part, potassium and silicon content in the leaf tissue, agronomic efficiency index and K extraction. It was possible to conclude that there are alternative sources to potassium chloride for the supply of potassium, varying according to soil textures and also the time of chemical interaction in the soil, many proved to be more agronomically efficient than the standard KCl source, and also proved to be sources of beneficial elements such as silicon.