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Registro Completo |
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Biblioteca(s): |
Embrapa Meio Norte / UEP-Parnaíba; Embrapa Soja. |
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Data corrente: |
07/01/1994 |
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Data da última atualização: |
23/09/1994 |
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Autoria: |
DENMEAD, O. T.; SHAW, R. H. |
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Afiliação: |
Iowa State University. Agronomy Department. Agricultural Climatology. Ames, Iowa. |
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Título: |
Availability of soil water to plants as affected by soil moisture content and meteorological conditions. |
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Ano de publicação: |
1962 |
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Fonte/Imprenta: |
Agronomy Journal, v.54, n.5, p.385-390, sept./oct. 1962. |
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Idioma: |
Inglês |
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Conteúdo: |
Dynamic aspects of the availability of soil water to plants are discussed briefly. IT is pointed out that as the soil dries, the actual transpiration rate should fall below the potential rate and that this decline in relative transpiration rate should occur at higher and higher soil mositure contents as the potential transpiration rate increases. Since the decline in relative transpiration rate results from a loss of turgor in the plant, the soil moisture content at which plants wilt should also increase as the potential transpiration rate increases. Transpiratin rates from corn plants grown in containers in the field were determined under varying conditions of soil water supply and varying potential transpiration rates. For moderate potential transpiration rates (3 to 4 mm. per day), the actual transpiration rate fell below the potential rate when the average soil suction in the root zone was about 2 bars. When the potential transpiration rates were as high as 6 to 7 mm. per day, this decline in relative transpiration rate occurred at about 0.3 bar. When the potential transpiration rate was only 1.4 mm. per day, the relative transpiration did not decline until about 12 bars. The soil moisture content at which the decline in relative transpiration rate occurred, referred to as the turgor loss point, varied from a volumetric soil moisture content of 23% when the potential rate was 1.4 mm. per day to 34% when the potential transpiration rate exceeded 6 mm. per day. Measurements of dry matter production suggested that one the soil moisture content was less than the turgor loss point, the plants virtually ceased to assimilate. MenosDynamic aspects of the availability of soil water to plants are discussed briefly. IT is pointed out that as the soil dries, the actual transpiration rate should fall below the potential rate and that this decline in relative transpiration rate should occur at higher and higher soil mositure contents as the potential transpiration rate increases. Since the decline in relative transpiration rate results from a loss of turgor in the plant, the soil moisture content at which plants wilt should also increase as the potential transpiration rate increases. Transpiratin rates from corn plants grown in containers in the field were determined under varying conditions of soil water supply and varying potential transpiration rates. For moderate potential transpiration rates (3 to 4 mm. per day), the actual transpiration rate fell below the potential rate when the average soil suction in the root zone was about 2 bars. When the potential transpiration rates were as high as 6 to 7 mm. per day, this decline in relative transpiration rate occurred at about 0.3 bar. When the potential transpiration rate was only 1.4 mm. per day, the relative transpiration did not decline until about 12 bars. The soil moisture content at which the decline in relative transpiration rate occurred, referred to as the turgor loss point, varied from a volumetric soil moisture content of 23% when the potential rate was 1.4 mm. per day to 34% when the potential transpiration rate exceeded 6 mm. per day. Measurem... Mostrar Tudo |
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Palavras-Chave: |
Availability; disponibilidade; Estresse hidrico; Plant. |
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Thesagro: |
Água; Climatologia; Planta; Solo; Stress. |
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Thesaurus Nal: |
climatology; soil; water. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02371naa a2200277 a 4500
001 1458491
005 1994-09-23
008 1962 bl --- 0-- u #d
100 1 $aDENMEAD, O. T.
245 $aAvailability of soil water to plants as affected by soil moisture content and meteorological conditions.
260 $c1962
520 $aDynamic aspects of the availability of soil water to plants are discussed briefly. IT is pointed out that as the soil dries, the actual transpiration rate should fall below the potential rate and that this decline in relative transpiration rate should occur at higher and higher soil mositure contents as the potential transpiration rate increases. Since the decline in relative transpiration rate results from a loss of turgor in the plant, the soil moisture content at which plants wilt should also increase as the potential transpiration rate increases. Transpiratin rates from corn plants grown in containers in the field were determined under varying conditions of soil water supply and varying potential transpiration rates. For moderate potential transpiration rates (3 to 4 mm. per day), the actual transpiration rate fell below the potential rate when the average soil suction in the root zone was about 2 bars. When the potential transpiration rates were as high as 6 to 7 mm. per day, this decline in relative transpiration rate occurred at about 0.3 bar. When the potential transpiration rate was only 1.4 mm. per day, the relative transpiration did not decline until about 12 bars. The soil moisture content at which the decline in relative transpiration rate occurred, referred to as the turgor loss point, varied from a volumetric soil moisture content of 23% when the potential rate was 1.4 mm. per day to 34% when the potential transpiration rate exceeded 6 mm. per day. Measurements of dry matter production suggested that one the soil moisture content was less than the turgor loss point, the plants virtually ceased to assimilate.
650 $aclimatology
650 $asoil
650 $awater
650 $aÁgua
650 $aClimatologia
650 $aPlanta
650 $aSolo
650 $aStress
653 $aAvailability
653 $adisponibilidade
653 $aEstresse hidrico
653 $aPlant
700 1 $aSHAW, R. H.
773 $tAgronomy Journal$gv.54, n.5, p.385-390, sept./oct. 1962.
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Registro original: |
Embrapa Soja (CNPSO) |
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