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Boaretto,Antonio Enedi; Spolidorio,Eduardo Scarpari; Freitas,José Guilherme de; Trivelin,Paulo Cesar Ocheuze; Muraoka,Takashi; Cantarella,Heitor. |
The wheat crop in São Paulo State, Brazil, is fertilized with N, P and K. The rate of applied N (0 to 120 kg.ha-1) depends on the previous grown crop and the irrigation possibility. The response of wheat to rates and time of N application and the fate of N applied to irrigated wheat were studied during two years. Residual N recovery by soybean grown after the wheat was also studied. The maximum grain productivity was obtained with 92 kg.ha-1 of N. The efficiency of 15N-urea utilization ranged from 52% to 85%. The main loss of applied 15N, 5% to 12% occurred as ammonia volatilized from urea applied on soil surface. The N loss by leaching even at the N rate of 135 kg.ha-1, was less than 1% of applied 15N, due to the low amount of rainfall during the wheat... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nitrogen fertilization; Efficiency; Ammonia; Volatilization. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052004000200011 |
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