Contribution of fertilizer nitrogen to the total nitrogen extracted by sugarcane under Brazilian field conditions - Vieira-Megda, Michele Xavier; Mariano, Eduardo; Leite, José Marcos; Franco, Henrique Coutinho Junqueira; Vitti, André César; Megda, Marcio Mahmoud; Khan, Saeed Ahmed; Mulvaney, Richard Lesley; Trivelin, Paulo Cesar Ocheuze (Nutrient Cycling in Agroecosystems, 2015)