Monoammonium phosphate coated with polymer in sunflower crop

Abstract

The use of polymers for the coating of phosphate fertilizers allows for a slower release of nutrients and, therefore, reduces their susceptibility to immobilization processes in the soil. Thus, the objective was to evaluate four sunflower varieties submitted to fertilization with phosphorus with and without polymer coatings in the Brazilian Cerrado. The research was carried out under field conditions in the municipality of Cassilândia (MS), with rainy summers and dry winters. The experimental design used was randomized blocks in a 4x2 factorial scheme, with 4 sunflower varieties (Embrapa 122, IAC Iarama, IAC Uruguay and Catissol 01) and 2 sources of phosphorus (supertriple phosphate without polymers and monoammonium phosphate with polymers), with 4 replications. The experimental unit (plot) consisted of 4 plants rows of 5 m long, spaced 0.70 m between rows, with a population of 50,000 plants per hectare. The variables evaluated were number of photosynthetically active leaves, height of plants and diameter of stem, diameter and number of head, mass of 1000 achenes and the productivity of grain. The use of polymers in the formulation of monoammonium phosphate fertilizer presents potential for use in sunflower crop. The sunflower plant response to fertilization with coated monoammonium phosphate depends on the cultivar used.