Efeito de ácidos húmicos/fúlvicos associados com nitrogênio no rendimento do milho

Abstract

Nitrogen is an essential nutrient for maize. It is also understood that humic / fulvic acids may present potential on the development of maize plants, however, few studies are observed regarding the influence of these compounds on the yield components of the crop. The objective of the study was to evaluate the morphological components of maize plants at the end of the cycle, besides the crop productivity components, grown in different treatments with isolated and/or associated use of nitrogen and humic/fulvic acids. The study was conducted at the Universidade Tecnológica Federal do Paraná, Câmpus Dois Vizinhos, during the period corresponding to the 2017/2018 harvest. A randomized block design was used, and seven treatments were evaluated, which were constituted by different times of application of humic / fulvic acids, associated or not with nitrogen, being: treatment 1: application of ½ dose of the technical recommendation of humic acids / fulvic in V4 + application of ½ dose in V8; treatment 2: full dose application of the technical recommendation of humic/fulvic acids in V4; treatment 3: full dose application of the technical recommendation for humic/fulvic acids in V8; treatment 4: use of nitrogen; treatment 5: application of full dose of the technical recommendation of humic / fulvic acids in V8 + nitrogen; treatment 6: application of full dose of the technical recommendation of humic / fulvic acids in V4 + nitrogen; treatment 7: no humic/fulvic acids and no use of nitrogen (control). Acids were applied via foliar and nitrogen coverage with levels of 170 kg ha-1. Data were submitted to analysis of variance and when found significant, a Scott-Knott test was applied at 5% probability. The use of humic / fulvic acids did not interfere in the morphological characteristics of the plants, nor on the yield components of the maize crop, when used alone or associated with nitrogen. On the other hand, nitrogen in the cover provided an increase in the number of grains per row and grains per spike, a thousand grain mass and yield per area and spike. Further studies on the subject need to be performed to confirm or deny such observed results.