Título:	Understanding N timing in corn yield and fertilizer N recovery: an insight from an isotopic labeled-N determination.
Autoria:	OLIVEIRA, S. M. de ALMEIDA, R. E. M. de CIAMPITTI, I. A. PIEROZAN JUNIOR, C. LAGO, B. C. TRIVELIN, P. C. O. FAVARIN, J. L.
Afiliação:	SILAS MACIEL DE OLIVEIRA, ESALQ; RODRIGO ESTEVAM MUNHOZ DE ALMEIDA, CNPASA; IGNACIO A. CIAMPITTI, KANSAS STATE UNIVERSITY; CLOVIS PIEROZAN JUNIOR, ESALQ; BRUNO COCCO LAGO, ESALQ; PAULO CESAR OCHEUZE TRIVELIN, CENA; JOSE LAERCIO FAVARIN, ESALQ.
Ano de publicação:	2018
Referência:	PLoS One, v. 13, n. 2, e0192776, Feb. 2018.
Conteúdo:	Early fertilizer nitrogen (N) application on cover crops or their residues during the off-season is a practice adopted in Brazil subtropical conditions under no-tillage corn (Zea mays L.) systems. However, the effect of early N application on yield, plant N content, and N recovery efficiency (NRE) for corn is not yet well documented. Five fertilizer N timings in an oat-corn system were evaluated in two studies utilizing an isotopic-labeled N determination, 15N isotope. The N fertilization timings were: (i) oat tillering, (ii) 15 days before corn planting time, over the oat residues, (iii) at corn planting time, (iv) in-season at the three-leaf growth stage (V3), and (v) in-season split application at V3 and six-leaf (V6) growth stages. Based on the statistical analysis, the N fertilization timings were separated into three groups: 1) N-OATS, designated to N applied at oat; 2) N-PLANT, referred to pre-plant and planting N applications; and 3) N-CORN, designated to in-season corn N applications. Corn yield was not affected by the N fertilization timing. However, the N-CORN N fertilization timings enhanced NRE by 17% and 35% and final N recovery system (plant plus soil) by 16% and 24% all relative to N-OATS and N-PLANT groups, respectively. Overall, N-OATS resulted in the largest N derived from fertilizer (NDFF) amount in the deeper soil layer, in overall a delta of 10 kg N ha-1 relative to the rest of the groups. Notwithstanding corn yield was not affected, early N fertilization under subtropical conditions is not a viable option since NRE was diminished and the non-recovery N increased relative to the in-season N applications.
Thesagro:	Milho Zea Mays Fertilizante Nitrogenado Plantio Direto Planta de Cobertura
NAL Thesaurus:	Corn Nitrogen fertilizers Cover crops No-tillage
ISSN:	1932-6203
Digital Object Identifier:	10.1371/journal.pone.0192776
Tipo do material:	Artigo de periódico
Acesso:	openAccess
Aparece nas coleções:	Artigo em periódico indexado (CNPASA)