Doses de nitrogênio na cultura antecessora e do milho em sistema plantio direto
Data
2008-01-31
Autores
Nascimento, Flavia Meinicke [UNESP]
Título da Revista
ISSN da Revista
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O aumento do emprego do Sistema Plantio Direto, no Brasil, tem revelado de maneira inquestionável a necessidade do aprofundamento das pesquisas que avaliem os efeitos das culturas antecessoras sobre culturas de gramíneas anuais, particularmente na cultura do milho. A presente pesquisa teve como objetivo avaliar a resposta da cultura do milho em sucessão às culturas de soja + aveia e milho + aveia, havendo a antecipação da aplicação do nitrogênio na cultura da aveia, em doses crescentes, no Sistema Plantio Direto. Foram conduzidos dois experimentos em condições de campo em solo classificado como NITOSSOLO VERMELHO distroférrico, na Fazenda Experimental Lageado, da Faculdade de Ciências Agronômicas da UNESP, Campus de Botucatu. No experimento nº1, foi realizada a seguinte sucessão de culturas: soja, aveia e milho; enquanto no experimento nº2, a sucessão de culturas foi: milho, aveia e milho. Nos dois experimentos foram consideradas parcelas as doses de nitrogênio aplicadas na cultura da aveia: 0, 20, 40 e 60 kg ha-1. As doses de nitrogênio aplicadas em cobertura na cultura do milho, foram consideradas subparcelas, variando nas seguintes doses: 60, 80, 100 e 120 kg ha-1, aplicados de forma parcelada em dois estádios da cultura do milho, a saber: 1ª aplicação no estádio de 3 a 4 folhas totalmente distendidas e a 2ª aplicação no estádio de 6 a 7 folhas totalmente distendidas. Na cultura da aveia foi avaliada a massa de matéria seca e calculada a relação C/N. Na cultura do milho foi calculada a relação C/N, quantificado o nitrogênio na planta antes da primeira cobertura e quinze dias após a aplicação da segunda cobertura, sendo nesta coeficientes de determinação (R2) tiveram sua significância testada ao nível de 5% de probabilidade e considerados significativos quando R2 foi superior a 60%. Os experimentos foram analisados estatísticamente separados...
The growing use of no–tillage system, in Brazil, has unquestionably revealed the need of deeper investigation to assess the effects of preceding cultures on current annual grass cultures, specially the corn ones. The main goal of this current research is to evaluate the response of corn plantation in succession on cultures of soybean + black oat and corn + black oat, with the antecipation of nitrogen applications in the black oat culture, in increasing doses, in no–tillage system. Two experiments in field conditions in soils classified as NITOSSOLO VERMELHO distroférrico were conducted, on Lageado Experimental Farm, at Faculdade de Ciências Agronômicas of UNESP, Botucatu Campus. On experiment nº1, the succession was conducted as follows: soybean, black oat and corn while on experiment nº2 the culture succession was: corn, black oat and corn. On both experiments, parcels of 0, 20, 40 e 60 kg ha-1 of nitrogen doses were applied on the black oat cultures. In relation to the corn cultures, subparcels were considered, varying on the following doses: 60, 80, 100 e 120 kg ha-1. The latter were applied gradually in two stages of the corn culture, as follows: 1st application on the stage of 3 to 4 totally unfolded leaves and the 2nd application on the stage of 6 to 7 totally unfolded leaves. On the black oat culture, the dry matter mass was assessed and the relation C/N calculated. On the corn culture the relation of C/N was also calculated; the nitrogen in the plants was quantified before the first covering and 15 days after the second At the end of the cicle, the plant and the first spike insertion heights and the stem diameter were measured and the spike indexes were calculated. After the harvest, the number of rows per spike was counted, the mass of 1000 grains was measured and the productivity was calculated. The data were submitted to the variance analysis and compared through the F test...(Complete abstract, click electronic access below)
The growing use of no–tillage system, in Brazil, has unquestionably revealed the need of deeper investigation to assess the effects of preceding cultures on current annual grass cultures, specially the corn ones. The main goal of this current research is to evaluate the response of corn plantation in succession on cultures of soybean + black oat and corn + black oat, with the antecipation of nitrogen applications in the black oat culture, in increasing doses, in no–tillage system. Two experiments in field conditions in soils classified as NITOSSOLO VERMELHO distroférrico were conducted, on Lageado Experimental Farm, at Faculdade de Ciências Agronômicas of UNESP, Botucatu Campus. On experiment nº1, the succession was conducted as follows: soybean, black oat and corn while on experiment nº2 the culture succession was: corn, black oat and corn. On both experiments, parcels of 0, 20, 40 e 60 kg ha-1 of nitrogen doses were applied on the black oat cultures. In relation to the corn cultures, subparcels were considered, varying on the following doses: 60, 80, 100 e 120 kg ha-1. The latter were applied gradually in two stages of the corn culture, as follows: 1st application on the stage of 3 to 4 totally unfolded leaves and the 2nd application on the stage of 6 to 7 totally unfolded leaves. On the black oat culture, the dry matter mass was assessed and the relation C/N calculated. On the corn culture the relation of C/N was also calculated; the nitrogen in the plants was quantified before the first covering and 15 days after the second At the end of the cicle, the plant and the first spike insertion heights and the stem diameter were measured and the spike indexes were calculated. After the harvest, the number of rows per spike was counted, the mass of 1000 grains was measured and the productivity was calculated. The data were submitted to the variance analysis and compared through the F test...(Complete abstract, click electronic access below)
Descrição
Palavras-chave
Aveia, Milho, Fertilizantes nitrogenados, Nitrogen fertilization, Corn, Black oat
Como citar
NASCIMENTO, Flavia Meinicke. Doses de nitrogênio na cultura antecessora e do milho em sistema plantio direto. 2008. xvii, 113 f. Dissertação (mestrado) - Universidade Estadual Paulista - Faculdade de Ciências Agronômicas de Botucatu, 2008.