Desenvolvimento e produtividade de milho adubado com diferentes fontes de nitrogênio e épocas de aplicação

Abstract

Corn is one of the main sources of food for animals and humans, a crop that stands out as one of the most cultivated in the world. The adequate development of the crop depends on some environmental factors, such as the nutrients present in the soil, such as nitrogen. The demand for this nutrient is usually supplied by reserving the soil fertilizations performed at the base and in coverage. Considering that nitrogen sources and times of application can directly interfere in the availability to culture. The objective of this experiment was to evaluate the source of nitrogen and the time of application, which will provide a better performance of the maize crop. The experiment was conducted in the experimental area of the Federal University of Southern Frontier, located in the municipality of Chapecó-SC, with a plot of 15 m² (3 x 5m) with 4 replications. The treatments were composed of 3x4 factorial, in which the first factor was composed of nitrogen sources (urea, ammonium sulphate and ammonium nitrate) and the second by application time, which were: 1 - base (20%) + v7 (80%); 2-base (10%) + v4 (40%) + v8 (50%); 3-base (100%); and 4 - control without fertilization. The corn cultivar used was DKB Pro3 with a seeding density of 7 seeds per m2. The evaluations were carried out in the blossoming by quantifying the stem diameter and height of the plants, the evaluations of green mass and later dry mass of the aerial part of the plants were carried out, as well as final analyzes were made evaluations of the height of spike insertion, number of rows per ear, number of grains per row, ear length, mass of one thousand grains and productivity. With the results obtained it is possible to conclude that the nitrogen source that presented the greatest contribution in the crop productivity was the nitrate plus ammonium, applied only in the base.