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Registro Completo |
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Biblioteca(s): |
Embrapa Trigo. |
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Data corrente: |
10/01/2010 |
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Data da última atualização: |
11/12/2012 |
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Autoria: |
MYERS, R. J. K. |
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Título: |
A simple model for estimating the nitrogen fertilizer requirement of a cereal crop. |
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Ano de publicação: |
1984 |
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Fonte/Imprenta: |
Fertilizer Research, v. 5, n. 1, p. 95-108, 1984. |
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Idioma: |
Inglês |
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Conteúdo: |
A static model that predicts the nitrogen (N) fertilizer requirement of grain sorghum or wheat crops is described. Inputs required by the model are soil nitrate-N (kg ha–1) in the profile at sowing, total N (%) in the plough layer, available water in the profile at sowing (mm) plus rainfall during the growing season (mm). Output includes fertilizer N required for both maximum yield and optimum economic yield. The model was tested by using published field data from Nebraska and Kansas (U.S.A.), South Australia and Northern Territory (Australia), and Saskatchewan (Canada). The model was accurate when no fertilizer N was required, and when large amounts were required, but quantitative prediction of moderate requirements was only fair. Predictions for grain sorghum were better than for winter wheat, probably because total water use was a better predictor of yield potential for grain sorghum than for winter wheat. Further refinement for specific environments should make the model practical for dryland cereal crops. |
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Palavras-Chave: |
Modelo para estimar o N a ser aplicado em sorgo e trigo. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 01457naa a2200133 a 4500
001 1840283
005 2012-12-11
008 1984 bl --- 0-- u #d
100 1 $aMYERS, R. J. K.
245 $aA simple model for estimating the nitrogen fertilizer requirement of a cereal crop.
260 $c1984
520 $aA static model that predicts the nitrogen (N) fertilizer requirement of grain sorghum or wheat crops is described. Inputs required by the model are soil nitrate-N (kg ha–1) in the profile at sowing, total N (%) in the plough layer, available water in the profile at sowing (mm) plus rainfall during the growing season (mm). Output includes fertilizer N required for both maximum yield and optimum economic yield. The model was tested by using published field data from Nebraska and Kansas (U.S.A.), South Australia and Northern Territory (Australia), and Saskatchewan (Canada). The model was accurate when no fertilizer N was required, and when large amounts were required, but quantitative prediction of moderate requirements was only fair. Predictions for grain sorghum were better than for winter wheat, probably because total water use was a better predictor of yield potential for grain sorghum than for winter wheat. Further refinement for specific environments should make the model practical for dryland cereal crops.
653 $aModelo para estimar o N a ser aplicado em sorgo e trigo
773 $tFertilizer Research$gv. 5, n. 1, p. 95-108, 1984.
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Registro original: |
Embrapa Trigo (CNPT) |
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