Sources of Potassic Fertilization in Soybean Production under Different Irrigation Blades

Aims: The objective of this research was to evaluate the physiological and biometric parameters of the soybean crop in potassic fertilization sources under different irrigation blades. Two potassium sources (ground rock, “phonolite”, with 9% K2O and potassium chloride with 60% K2O) and five irrigation blades (30, 70, 100, 130 and 160% of the recommended blade) were used.

Study Design: The experimental design was in randomized blocks, with ten treatments and four replications, in a 2 x 5 factorial scheme, totaling 40 vessels.

Place and Duration of Study: Sample: Department of Agronomy, UNIFENAS, between March 2018 and November 2018.

Methodology: Soil moisture was determined through tensiometers, using a water potential of -30kPa, considered adequate for the soybean crop. At the end of the crop cycle, the weight of shoot dry matter, weight of 1000 seeds, weight of seeds standardized to 13% moisture, total chlorophyll, chlorophyll a, chlorophyll b and carotenoids, besides nutrient content of the leaf tissue, were evaluated.

Conclusion: KCl favors the accumulation of dry matter, weight of 1000 grains and grain production in the soybean crop in the different irrigation blades. Phonolite increases calcium and magnesium contents in the leaves, independently of the irrigation blade used, also favoring the increase in phosphorus and sulfur contents when soil moisture increases.