RELEASE OF POTASSIUM FERTILIZER COATED WITH POLYMER

• DOI: 10.22533/at.ed.9732162230112

• Palavras-chave: potassium chloride; polyurethane; controlled release; release curve.

• Keywords: potassium chloride; polyurethane; controlled release; release curve.

• Abstract:

  Among the challenges faced in agriculturalproduction, one of the mainones is directed to the search for new ways to achievegreaterefficiencies of inputs, especiallyfertilizers, sincetheyhavegreatimportanceamong the factors of production. The line of research on fertilizerswithaggregatedtechnologiesappears as one of the possiblealternatives, and the physicalcoating of fertilizer granules is a relevantoption to bestudied. The objectivewas to study the dynamics of release of controlled release potassiumfertilizer (coated), verifying the influence of percentages of coatingapplied to the fertilizer and its reflexes on the time required for release. Identicalexperimentswerecarried out in a controlledenvironment (laboratory) and in a greenhouse. 5 percentages of polyurethanepolymerwereused for the coating of potassiumchloride (KCl) and a treatment without coating. Using porous bags, madewithpermeablescreens, the fertilizerswereallocated and theywereburied in potscontaining 1 kg of a Red-yellowLatosol. Weekly, collections of porous bags containing the fertilizerwereperformed and the material wassent for chemicalanalysis. The results, analyzedbymeans of comparisontest (Duncan at 5% of significance) at the end of the experiment, showedthat overlays greaterthan 6.75% (m/m) delay the release of KCl to the soil and, to the extent that thatif the percentage of coverage is increased, the release isreduced, regardless of the placewhere the fertilizerisallocated. Thus, physical protection canbe considered as analternative to improving the use of this input.