Produção Nacional
Revisado por pares
Nutrição em nitrogênio do capim Marandu submetido a doses de nitrogênio e idades de crescimento
2003; INSTITUTO DE ZOOTECNIA IZ/APTA-SAA/SP; Volume: 60; Issue: 2 Linguagem: Inglês
ISSN
1981-4100
AutoresJoão de Deus Gomes dos Santos, Francisco Antônio Monteiro,
Tópico(s)Crop Yield and Soil Fertility
ResumoThe objective of this research was to examine the forage yield, critical and total nitrogen concentration, related to SPAD values in the most recently expanded leave blade of Marandu grass (Brachiaria brizantha cv. Marandu) under nitrogen rates of 28, 112, 210, 294 and 378 mg L-1 and growth ages of 21, 28, 35, 42, 49 and 56 days after seedling emergence. The experiment was carried out in a greenhouse, with nutrient solution using ground quartz as substrate. The experimental design was a complete randomized block design, with treatments arranged in a factorial, with four replications. Nitrogen rates and growth ages interaction was significant for all studied attributes of Marandu grass. Maximum dry matter yield was estimated to occur at nitrogen rates between 257 and 304 mg L-1, depending on plant age. The critical nitrogen concentration determined in the most recently expanded leaf blade was significantly influenced by plant ages and ranged from 33.8 to 12.8 g kg-1. SPAD values at the critical nitrogen concentration ranged from 45 to 50 when growth periods ranged from 21 to 49 days.
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