Doses de 30-00-20 na adubação de cobertura do milho segunda safra

Abstract

Nitrogen and potassium are the nutrients most in demand by corn, but due to the low uptake capacity of the crop in the early stages of development, top dressing becomes crucial to obtain high yields. Based on the importance and the difficulty of management of fertilizer cover, this study was conducted with the objective of evaluating whether the joint application of nitrogen and potassium in the fertilizer cover interferes in the development and production of second-crop corn. A randomized block design was adopted, with five repetitions and five treatments (0, 100, 200, 300, 400 kg ha-1 of the formulation 30-00-20). Covering fertilizer was applied at the V4 stage. The morphological characteristics were evaluated: plant height, stem diameter, chlorophyll index, and the production components: number of rows per ear, number of grains per ear, plot grain mass, and grain yield. Based on the results obtained, it was concluded that: a) The covering fertilization with the formulated 30-00-20 promotes beneficial effects on the development and production of second-crop corn; b) the second-crop corn culture responds to covering fertilization up to a dose of 400 kg ha-1 of 30-00-20; c) application of 400 kg ha-1 of the formulated 30-00-20 results in maximum secondcrop corn productivity.