Potassium fertilization on yield forage and chemical composition of Arachis pintoi cv. Amarillo

Abstract

The effect of potassium fertilization on the yield of dry matter (DM) and chemical composition of Arachis pintoi cv. Amarillo, was evaluated under greenhouse conditions. The experimental design was randomized blocks with four replicates. The treatments consisted of five levels of potassium (0, 15, 30, 45 and 60 mg of K/kg soil), implemented in the form of potassium chloride. Potassium fertilization significantly increased the yields of DM and potassium contents, while the opposite occurred for concentrations of nitrogen and phosphorus. The maximum yield of DM was obtained with the application of K/dm³ 54.72 mg, while the higher potassium content was verified by the application of 24.43 mg K/dm³. The internal critical potassium level associated with 90% of the maximum yield of DM was estimated at 1.91%. Large doses are less efficient in the use of potassium. The calcium and magnesium contents were not affected by potassium levels used.