Fontes e doses de nitrogênio associado a doses de Azospirillum sp. na emissão de CO2 e produtividade de milho no sistema de consórcio milho e cana-de-açucar

Abstract

CO2 emissions have been studied due to the commitment of countries to reduce greenhouse gases, and sustainable agriculture is one of the main factors that can contribute to this reduction. Intercropping systems increase the carbon stock in the soil, but increase the demand for nutrients to maintain high yields. With this in mind, the objective of this research was to evaluate the effects of nitrogen sources and doses associated with the application of Azospirillum brasilense in maize and sugarcane intercropping on carbon dioxide (CO2) emissions from the soil and maize production. The experiment was carried out in January 2024 at municipality of Chapadão do Céu - GO. The soil in the experimental area is classified as Latossolo Vermelho distroférrico. The experimental area was cultivated with sugarcane for 9 cuts and we evaluated the productive performance of the maize and CO2 emissions in this environment. The experimental design used was randomized blocks in a subdivided plot scheme, with four replications. In the plots, two experiments were carried out with two maize hybrids and in the subplots, the N sources (urea and ammonium nitrate), doses of inoculation with Azospirillum brasilense (SI: no inoculation, DP: 100 ml ha-1, 2DP: 200 ml ha-1; 3 DP: 300 ml ha-1) and nitrogen fertilizer doses (D1=0 kg ha-1; D2 = 60 kg ha-1; D3 = 120 kg ha-1; D4 = 180 kg ha-1 and D5 = 240 kg ha-1). Corn yields and CO2 emissions were evaluated at three corn stages. It was found that the use of inoculants reduced CO2 emissions when ammonium nitrate was used and that we can reduce the doses of nitrogen in the maize crop with inoculation without losing productivity, although the results varied according to the hybrids used.