Adubação nitrogenada amídica e nítrica em campo de produção de sementes de trigo no Sul do Rio Grande do Sul

Abstract

Wheat is the second most cultivated and consumed cereal in the world, and in Brazil there is a socioeconomic interest in increasing its production, since more than half of the domestic demand for the cereal is imported. Nitrogen fertilization is an important alternative for increasing wheat yield, since in addition to this benefit, it possibly improves seed physiological quality. The nitrogen fertilizer most used in Brazil is urea, which can have high volatilization losses due to adverse weather conditions and urea hydrolysis reactions when in contact with the soil. Due to urea losses, nitrogen fertilizers based on ammonia and nitric can be an important alternative to minimize losses by volatilization. In this sense, the objective of the present study is to evaluate the productivity and quality of wheat seeds of the cultivar Tbio Audaz®, under nitrate ammonium nitrogen fertilization in southern Brazil. The experiment was conducted between June and October 2021, at the experimental field of Federal University Federal of Pelotas, in the city of Capão do Leão, Rio Grande do Sul. The experiment was arranged in a randomizes block design, in a 2x4 factorial, where the factor 1 consisted of two sources of nitrogen, one amide (urea) and the other nitrate and ammonium (ammonium nitrate), and factor 2 consisted of doses of nitrogen 0, 40, 80 and 120 kg N ha-1, with 4 replications. Yield components (number of tillers per plant (TP), plant height (PH), ear insertion height (EH), ear size (ES), number of spikelet’s per ear (NSE), number of seeds per ear (NGE) and number of ears, dry matter and grain yield, thousand seed weight, hectoliter weight, crude protein content were evaluated. Also, seed physiological quality was evaluated through the analysis of germination, length and dry weight of seedlings, electrical conductivity, nitrogen content in the seed, accelerated aging and field emergence. Linear growth of yield components, grain yield and dry matter was observed. With the results obtained, the grain and dry matter yield increases with the increment of nitrogen fertilization. Seed nitrogen content is response to higher ammonium nitrate supplementation and increases with increasing doses. Germination did not change with nitrogen fertilization regardless of dose and nitrogen source.