Épocas de adubação nitrogenada na cultura do milho e sua influência na cultura subsequente, girassol, em sistema de semeadura direta
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Data
2009-06-22
Autores
Freire, Luciana Maria da Silva [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O rendimento de grãos de milho é influenciado pela disponibilidade de nitrogênio no solo durante o ciclo de desenvolvimento da planta. O objetivo deste trabalho foi avaliar em sistema de semeadura direta, os resultados obtidos com a adubação nitrogenada em pré-semeadura e em cobertura na cultura do milho analisando a produtividade de grãos desta cultura e da cultura subsequente, o girassol. O experimento foi conduzido em uma área no sistema de semeadura direta há cinco anos, no Sítio Santo Antônio em Pirassununga, SP no ano agrícola 2004/2005. Utilizou-se o delineamento experimental de parcelas subdivididas, sendo 3 híbridos de milho, 4 épocas de adubação e 5 repetições. A dose em cobertura de 102,5 kg ha-1 N, com o adubo 25-15-10, tendo como fonte de N o nitrato de amônio, foi aplicado nas seguintes épocas: Tratamento 1 (E1): testemunha (sem aplicação antecipada e sem cobertura de N); Tratamento 2 (E2): todo N em cobertura com milho de 3 a 4 folhas expandidas; Tratamento 3 (E3): em cobertura metade da dose de N com milho de 3 a 4 folhas expandidas e o restante de N com milho de 7 a 8 folhas expandidas; e Tratamento 4 (E4): metade da dose de N em pré-semeadura (15 dias antes da semeadura), e a metade restante de N em cobertura com milho de 3 a 4 folhas expandidas. Após a colheita do milho semeou-se girassol nestas áreas. Como resultado para o milho tem-se os híbridos se comportaram de maneira diferentes quanto as épocas de adubação de cobertura de N, onde os híbridos AG 8060 e Pointer não apresentam diferenças significativas entre a E2, E3 e E4; já o híbrido DKB 390 apresenta sua melhor resposta na E2 e a menor média na E4. Para a cultura do girassol, as épocas de adubação de milho não interferem na produtividade, porém, o girassol semeado após o híbrido DKB 390 apresenta menor produtividade quando comparado com os híbridos AG 8060 e Pointer.
The income of grains of corn is influenced by the avaiability of nitrogen in soil during the cycle of a plant development. The mainly objective of this research evaluate the results obtained with the nitrogen fertilization in pre-sowing and in covering of the culture of corn in a no-tillage system analyzing the productivity of grains from this culture and the subsequent culture, the sunflower. The experimented was in an area were there had already been developed the no-tillage system for five years, in the Santo Antônio Farm in Pirassununga, SP, in agricultural year 2004/2005. Used the experimental outline of subdivided parcels, being 3 corns hybrids, 4 timings of fertilization and 5 repetitions. The dose covering 102,5 kg ha-1 N, with 25-15-10 fertilizer, and as a source of N ammonium nitrate was applied at the following times: Treatment 1 (E1): testimony ( without anticipated application of without application of N in covering); Treatment 2 (E2): all N in covering with corn of 3 to 4 expanded leaves; Treatment 3 (E3): in covering with half dose of N with corn of 3 to 4 expanded leaves and half of the left dose of N with corn of 7 to 8 expanded leaves; and Treatment 4 (E4): half dose of N in pre-sowing (15 days before sowing), and half dose of N in covering with corn of 3 to 4 expanded leaves. After of harvest of corn was sowing sunflower this area. As result for the corn has been the hybrids behaved as different seasons as the times of covering fertilization of N, where the hybrid AG 8060 and Pointer not differ significantly between the E2, E3 and E4; since the hybrid DKB 390 presents its best response in the E2 and the lowest average in the E4. For the culture of sunflower, the times of fertilization of corn does not interfere with productivity, however, the sunflower sown after the hybrid DKB 390 has lower productivity compared to the hybrid AG 8060 and Pointer.
The income of grains of corn is influenced by the avaiability of nitrogen in soil during the cycle of a plant development. The mainly objective of this research evaluate the results obtained with the nitrogen fertilization in pre-sowing and in covering of the culture of corn in a no-tillage system analyzing the productivity of grains from this culture and the subsequent culture, the sunflower. The experimented was in an area were there had already been developed the no-tillage system for five years, in the Santo Antônio Farm in Pirassununga, SP, in agricultural year 2004/2005. Used the experimental outline of subdivided parcels, being 3 corns hybrids, 4 timings of fertilization and 5 repetitions. The dose covering 102,5 kg ha-1 N, with 25-15-10 fertilizer, and as a source of N ammonium nitrate was applied at the following times: Treatment 1 (E1): testimony ( without anticipated application of without application of N in covering); Treatment 2 (E2): all N in covering with corn of 3 to 4 expanded leaves; Treatment 3 (E3): in covering with half dose of N with corn of 3 to 4 expanded leaves and half of the left dose of N with corn of 7 to 8 expanded leaves; and Treatment 4 (E4): half dose of N in pre-sowing (15 days before sowing), and half dose of N in covering with corn of 3 to 4 expanded leaves. After of harvest of corn was sowing sunflower this area. As result for the corn has been the hybrids behaved as different seasons as the times of covering fertilization of N, where the hybrid AG 8060 and Pointer not differ significantly between the E2, E3 and E4; since the hybrid DKB 390 presents its best response in the E2 and the lowest average in the E4. For the culture of sunflower, the times of fertilization of corn does not interfere with productivity, however, the sunflower sown after the hybrid DKB 390 has lower productivity compared to the hybrid AG 8060 and Pointer.
Descrição
Palavras-chave
Adubação, Milho, Analise cromatografica, Semeadura, Anticipated fertilization, Nitrogen, Corn, No-tillage system
Como citar
FREIRE, Luciana Maria da Silva. Épocas de adubação nitrogenada na cultura do milho e sua influência na cultura subsequente, girassol, em sistema de semeadura direta. 2009. xii, 92 f. Dissertação (mestrado) - Universidade Estadual Paulista , Faculdade de Ciências Agronômicas de Botucatu, 2009.