Radish production function of the potassium fertilization and different nitrogen sources

Abstract

This study aimed to evaluate the response of radish to potassium fertilization and different nitrogen sources. The experimental design was a randomized block with treatments arranged in a factorial 5 x 2 (five doses of potassium, and two sources of nitrogen) with four replications. Potassium doses were 0, 40, 80, 120, and 160 kg ha^-1 of K₂O, and sources of nitrogen were ammonium sulfate ((NH₄)₂ SO₄) and urea (CO(NH₂)₂). 35 days after sowing the following variables were evaluated: root diameter, fresh root mass, root dry mass, leaf fresh mass, and leaf dry mass, leaf nitrogen content, number of marketable and non-marketable roots and crop productivity. Potassium application, regardless of the nitrogen supply, influenced radish performance and the dose of 103 kg ha^-1 K₂O promoted maximum productivity, under our experimental conditions. We conclude that, even in high soil potassium content, potassium fertilization should be recommended to obtain higher radish yield.