Doses de nitrogênio e potássio na cultura do milho em sistemas de cultivo orgânico e convencional

Abstract

Corn is one of the main agricultural crops of great economic importance, being used for various purposes, requiring the adoption of methods to increase its production, such as fertilization. The objective of the work was to evaluate the agronomic characteristics of corn depending on cultivation systems and nitrogen and potassium fertilization doses in the harvest and off-season. The experiment was conducted in Palotina-PR and Assis Chateaubriand-PR, with the organic and conventional production systems, respectively, in the period from 2021 to 2022, with the second harvest (safrinha) and the normal harvest. The design used was randomized blocks in a 4 x 4 factorial scheme, with two different factors at 4 levels, with four doses of N and K2O (0, 50, 100 and 200 kg ha-1). The corn variety IPR164 was used and the variables analyzed were the agronomic characteristics (population, height, number of ears, number of rows of grains, number of grains per row, mass of one thousand grains and productivity). The agronomic characteristics did not suffer statistical differences with the treatments used in the 2nd harvest of 2021. However, in the cultivation of the normal harvest, comprising 2021/2022, the agronomic characteristics did not suffer statistical differences in the organic cultivation system, while in the conventional cultivation system presented for the number of ears and productivity. The environmental conditions present in both harvests, such as low precipitation and temperature, may have affected the plant's response to the treatments used in the present work. Nitrogen and potassium alone or together showed no statistical difference with the increase in their doses in the corn crop in both cropping systems in the off-season, while in the harvest, it only showed for the characteristics number of ears and productivity in the cropping system conventional.