Evaluation of nitrogen fertilizer sources in Urochloa brizantha cv. Marandu palisade grass pastures on the performance of breeding Nellore bulls and greenhouse gas emissions

• Grant number: 24/10044-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: October 01, 2024
• End date: April 30, 2027
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Ricardo Andrade Reis
• Grantee: Izabela Larosa Rigobello
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Associated research grant: 22/15974-0 - Strategic grazing management and supplementation towards sustainable intensification at tropical pasture-based beef cattle production systems, AP.TEM

Abstract

Brazilian livestock farming is one of the main contributors to the country's economy, mostly developed on pasture in an extensive system. Using nitrogen fertilizers is a management strategy that can contribute to the mitigation of greenhouse gases, improving the nutritional quality of the forage and animal performance, intensifying the system, producing more in less time and in a smaller area, making it a sustainable alternative. This study aims to evaluate the effects of using nitrogen fertilizers in the following treatments, 1 - without using nitrogen fertilizer (control); 2 - fertilization with urea; 3 - fertilization with ammonium sulfate; 4 - fertilization with ammonium nitrate, in Urochloa brizantha marandu palisade grass on forage mass and allowance, the morphological characteristics of the pasture, nutritional value, consumption, digestibility, nitrogen balance, animal performance, gain per area and stocking rate, as well as quantifying greenhouse gases and the ammonia volatilization. The study will be carried out during the backgrounding phase of young bulls during the rainy season. 12 paddocks and 48 test animals, young Nellore bulls (Bos taurus indicus) with an average initial body weight of approximately 280 kg, will be used to evaluate animal performance. The static closed chamber method will quantify N2O, CH4, and CO2 emissions. Explanatory variables will be assessed to determine ecosystem interactions of soil, plant, animal, atmosphere, and climate. Pasture management will be a continuous stocking system with a variable stocking rate (put-and-take) with a pasture height target of 25 cm.