Effect of different nitrogen fertilizers on nitrogen efficiency use in Nellore bulls grazing on Marandu palisade grass

• Autor(a) principal: Fonseca, Natalia Vilas Boas [UNESP]
• Data de Publicação: 2022
• Outros Autores: Cardoso, Abmael da Silva, Berça, Andressa Scholz [UNESP], Dornellas, Isadora Alves [UNESP], Ongaratto, Fernando [UNESP], Silva, Maria Luisa Curvelo [UNESP], Ruggieri, Ana Cláudia [UNESP], Reis, Ricardo Andrade [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.livsci.2022.105012; http://hdl.handle.net/11449/241368
• topic: Cattle; Grazing; Nitrogen fertilization; Warm-season grass

We evaluated the effects of different sources of nitrogen (N) applied to pastures of Urochloa brizantha cv. Marandu during the rainy season on the efficiency of N use in plants and animals. Continuous grazing with variable stocking rates was employed to maintain 25 cm pasture height, corresponding to 95% light interception. The experimental design consisted of randomized blocks with four treatments and three replications (paddocks per treatment). The applied N sources were urea, ammonium sulfate, and ammonium nitrate, at a respective dosage of 150 kg N per ha, in three treatments, in addition to a control treatment without N fertilization. N recovery by plants differed between fertilizers (p = 0.047) and was highest in the ammonium sulfate treatment. The proportion of retained N was higher in animals kept on fertilized pastures (p < 0.01). Different sources of N in pasture system, or its non-use, affected the efficiency of N use by animals, and ammonium sulfate and ammonium nitrate were more efficient with respect to the N balance.