Nitrogen fertilizer increased litter deposition and litter N in warm-climate grasslands

Autor(es)

Longhini, Vanessa Z. ^[1] ; Cardoso, Abmael S. ^[1] ; Berca, Andressa S. ^[1] ; Carvalho, Isabel N. O. ^[2] ; Boddey, Robert M. ^[2] ; Reis, Ricardo A. ^[1] ; Dubeux, Jr., Jose C. B. ^[3] ; Ruggieri, Ana C. ^[1]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ, Dept Anim Sci, Via Acesso Prof Paulo Donato Castellane, BR-14884900 Jaboticabal, SP - Brazil

^[2] Embrapa Agrobiol, Rodovia BR 465, Km 7, BR-23891000 Seropedica, RJ - Brazil

^[3] Univ Florida, North Florida Res & Educ Ctr, Marianna, FL 32446 - USA

• Tipo de documento: Artigo Científico
• Fonte: NUTRIENT CYCLING IN AGROECOSYSTEMS; v. 119, n. 2 JAN 2021.
• Citações Web of Science: 0

Resumo

In warm-climate grasslands, litter deposition and decomposition are one of the main pathway of nutrient cycling. The application of nitrogen (N) fertilizer or the inclusion of a legume in such grasslands modifies litter characteristics and chemical composition. This study evaluated how the N supply of palisadegrass {[}Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster] pastures affect litter characteristics two years after seeding. Treatments were palisadegrass fertilized or not with N (150 or 0 kg N ha(-1) year(-1)) or mixed with the legume forage peanut (Arachis pintoi cv. Amarillo). The experimental period covered two consecutive rainy seasons. Nitrogen fertilization increased by 43 and 62% the existing litter mass (organic matter, OM), and by 32 and 23% the litter deposition rate compared to unfertilized palisadegrass or legume-grass mixtures, respectively. Both variables were affected by grazing cycle (GC), with low litter deposition rate (14 kg ha(-1) d(-1) OM) and existing litter mass (1390 kg ha(-1) OM) in the GC4 due to low rainfall. Nitrogen fertilized palisadegrass had greater litter N concentration (7.9 +/- 0.4 g kg(-1) OM-C:N ratio 34 +/- 2) than in monoculture or legume-grass mixtures (C:N ratios 45 and 58 +/- 2, respectively). Our results indicated that N fertilization of palisadegrass increased litter accumulation, however, N fertilization was not a key driver of the litter decomposition rate, even though it increased litter N concentration. After 2 years of establishment, the proportion of forage peanut in the litter was still low, reducing the benefits of legume inclusion to enhance litter nutrient cycling in these pastures. (AU)

• Processo FAPESP: 16/11086-1 - Mitigação de gases de efeito estufa em pastos de Capim-Marandu manejados com leguminosa ou fertilizante nitrogenado
• Beneficiário: Vanessa Zirondi Longhini
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 17/11274-5 - Decomposição de serrapilheira e emissão de gases de efeito estufa em pastos de Brachiaria adubados com doses crescentes de nitrogênio
• Beneficiário: Abmael da Silva Cardoso
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 15/16631-5 - Estratégias de manejo para redução de impactos ambientais em sistemas de produção de bovinos de corte
• Beneficiário: Ricardo Andrade Reis
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático