Effect of different sources of nitrogen fertilizers on methane emissions in capim marandu pastures

• Grant number: 22/00508-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2022
• End date: September 01, 2024
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Ricardo Andrade Reis
• Grantee: Marcelo Augusto Oliveira Castro
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Associated scholarship(s): 23/12910-3 - Water-based methane mitigation, BE.EP.IC

Abstract

Beef production is an important activity for the Brazilian economy, and the main production system is pasture farming. However, the productivity found in the country is still low due to poorly managed and degraded pastures. Nitrogen fertilization associated with management can significantly improve forage production, and may present different results depending on the amount and nitrogen source applied, however, nitrogen fertilizers can alter the flow of greenhouse gas (GHG) emissions from the soil. In Brazil, about 74.4% of the methane (CH4) emitted into the atmosphere comes from the agricultural sector, little is known about the influence of nitrogen fertilization on the production of this gas. In this sense, the objective of this work is to quantify CH4 emissions from different nitrogen sources applied to marandu grass pastures. The study will be conducted at FCAV/UNESP Campus of Jaboticabal-SP during the rearing phase of animals kept in pastures managed at a height of 25 to 30 cm in a continuous stocking system with adjustment of stocking rate (put-and-take). Nitrogen fertilization will occur in the rainy season with three different sources (treatments): urea, ammonium nitrate and ammonium sulfate at the same nitrogen dosage, split into three applications of 50 kg N ha-1, totaling 150 kg N ha-1. Twelve paddocks will be used, 3 replicates (paddocks) per treatment and CH4 emissions will be evaluated using 5 replicates (chambers) per treatment. Methane emissions and some explanatory variables will be quantified, such as temperature, rainfall and soil moisture. The hypothesis of the present study is that the ammonium sulfate source will result in lower methane emissions.(AU)