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Registro Completo |
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Biblioteca(s): |
Embrapa Mandioca e Fruticultura. |
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Data corrente: |
14/01/2002 |
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Data da última atualização: |
16/03/2023 |
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Autoria: |
SADLER, E. J.; BAUER, P. J.; BUSSCHER, W. J.; MILLEN, J. A. |
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Título: |
Site-specific analysis of a droughted corn crop: II water use and stress. |
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Ano de publicação: |
2000 |
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Fonte/Imprenta: |
Agronomy Journal v.92, n.3, p.403-410, 2000. |
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Idioma: |
Inglês |
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Conteúdo: |
In the southeastern USA Coastal Plain, spatial variation in soils causes extreme spatial variation in grain yield, as seen in yield maps. Corn (Zea mays L.) appears to be particularly susceptible to soil variation, especially during periods of drought. Our objectives were to compare variation in water use and stress of corn within and among soil map units. In one field, at two sites in each of four map units, we measured site-specific effects of soil variation on crop water use from 40 d after planting until after maturity using a time-domain reflectometer (TDR). On 4 d during vegetative growth, drought stress was evaluated on eight transects using infrared thermometer (IRT) measurements of canopy temperature (Tc). During the most severe drought, visibly stressed areas had canopy-air temperature differences (Tc − Ta) > 10°C, yet other areas remained <2°C. Two days after a 46-mm rain, Tc − Ta was near zero over the whole field, indicating little water stress. The time series of TDR measurements produced estimates of daily evapotranspiration, runoff, and infiltration; site-to-site differences in these dominated the water balance. Water stress, inferred from water use, matched that inferred earlier from yield components. In sum, corn at the eight sites arrived at final water use via fundamentally different paths. Further, variation between sites within soils was significant, indicating that soil map units are not homogenous with respect to water relations. These results underscore the need for within-season observations of crop water use and stress to augment interpretation of site-specific yield maps. MenosIn the southeastern USA Coastal Plain, spatial variation in soils causes extreme spatial variation in grain yield, as seen in yield maps. Corn (Zea mays L.) appears to be particularly susceptible to soil variation, especially during periods of drought. Our objectives were to compare variation in water use and stress of corn within and among soil map units. In one field, at two sites in each of four map units, we measured site-specific effects of soil variation on crop water use from 40 d after planting until after maturity using a time-domain reflectometer (TDR). On 4 d during vegetative growth, drought stress was evaluated on eight transects using infrared thermometer (IRT) measurements of canopy temperature (Tc). During the most severe drought, visibly stressed areas had canopy-air temperature differences (Tc − Ta) > 10°C, yet other areas remained <2°C. Two days after a 46-mm rain, Tc − Ta was near zero over the whole field, indicating little water stress. The time series of TDR measurements produced estimates of daily evapotranspiration, runoff, and infiltration; site-to-site differences in these dominated the water balance. Water stress, inferred from water use, matched that inferred earlier from yield components. In sum, corn at the eight sites arrived at final water use via fundamentally different paths. Further, variation between sites within soils was significant, indicating that soil map units are not homogenous with respect to water relations. These res... Mostrar Tudo |
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Thesagro: |
Solo. |
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Categoria do assunto: |
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Marc: |
LEADER 02121naa a2200169 a 4500
001 1650340
005 2023-03-16
008 2000 bl uuuu u00u1 u #d
100 1 $aSADLER, E. J.
245 $aSite-specific analysis of a droughted corn crop$bII water use and stress.$h[electronic resource]
260 $c2000
520 $aIn the southeastern USA Coastal Plain, spatial variation in soils causes extreme spatial variation in grain yield, as seen in yield maps. Corn (Zea mays L.) appears to be particularly susceptible to soil variation, especially during periods of drought. Our objectives were to compare variation in water use and stress of corn within and among soil map units. In one field, at two sites in each of four map units, we measured site-specific effects of soil variation on crop water use from 40 d after planting until after maturity using a time-domain reflectometer (TDR). On 4 d during vegetative growth, drought stress was evaluated on eight transects using infrared thermometer (IRT) measurements of canopy temperature (Tc). During the most severe drought, visibly stressed areas had canopy-air temperature differences (Tc − Ta) > 10°C, yet other areas remained <2°C. Two days after a 46-mm rain, Tc − Ta was near zero over the whole field, indicating little water stress. The time series of TDR measurements produced estimates of daily evapotranspiration, runoff, and infiltration; site-to-site differences in these dominated the water balance. Water stress, inferred from water use, matched that inferred earlier from yield components. In sum, corn at the eight sites arrived at final water use via fundamentally different paths. Further, variation between sites within soils was significant, indicating that soil map units are not homogenous with respect to water relations. These results underscore the need for within-season observations of crop water use and stress to augment interpretation of site-specific yield maps.
650 $aSolo
700 1 $aBAUER, P. J.
700 1 $aBUSSCHER, W. J.
700 1 $aMILLEN, J. A.
773 $tAgronomy Journal$gv.92, n.3, p.403-410, 2000.
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Embrapa Mandioca e Fruticultura (CNPMF) |
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