Yield and production components of soybean fertilized with different doses of phosphorus, potassium and zinc

The correct productivity increment must be allied to the technological advance in the knowledge of the nutritional requirements of each culture, thus allowing for the correct use of the inputs in the agricultural property. With the objective of studying the plants of soybean reply to zinc (Zn) in relation to the different doses of phosphorus (P) and potassium (K), this experiment was performed in the municipality of Palotina-PR. The soil was classified as typic hapludalf. The treatments were arranged in a 3x3 factorial scheme, constituting three fertilization forms with P(2)O(5) e K(2)O: without fertilization, recommended dose and twice the recommended fertilization dose by the soil analysis and three Zn doses (0; 2 and 4 kg ha(-1)). Nutrient sources used were bicalcic phosphate for P, potassium chloride for K and zinc sulphate for Zn. The applied Zn doses did not significantly influence productivity, so supplementing the base fertilization form is not justified. On other hand, fertilization with P(2)O(5) e K(2)O resulted in a significant increase in productivity and an increase in the number of legumes per plant, with an increase of the doses of these nutrients in the soil.