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Biblioteca(s): |
Embrapa Meio Norte / UEP-Parnaíba. |
Data corrente: |
15/07/1996 |
Data da última atualização: |
24/08/2009 |
Autoria: |
CAHN, M. D.; ZOBEL, R. W.; BOULDIN, D. R. |
Título: |
Relationship between root elongation rate and diameter and duration of growth of lateral roots of maize. |
Ano de publicação: |
1989 |
Fonte/Imprenta: |
Plant and Soil, v. 119, n. 2, p. 271-279, 1989. |
Idioma: |
Inglês |
Conteúdo: |
The objective of this work was to describe the relationship between elongation rate and diameter of maize roots and to estimate the length and growth duration of lateral roots of maize. Diameters and elongation rates of roots were measured in situ on plants grown 5 weeks in small rhizotrons under greenhouse conditions. At the end of the experimental period the roots were harvested and diameters of axile and lateral roots were measured. The frequency distribution of diameters of harvested roots was bimodal with a minimum at 0.6 mm; 97% of axile roots were larger than this value and 98% of the lateral roots were smaller. Root elongation per day increased as diameter increased but the slope of the relationship with lateral roots was about 2.5 times that with axile roots when separate linear regressions were fitted to the two populations. The length of lateral roots found on axillary roots between the base and about 30 cm from the apex was approximately 2.2 cm. All of the data was consistent with the hypothesis that the lateral roots grew for about 2.5 days and the ceased growing. The axillary roots continued to grow throughout the experimental period at a rate of about 3 cm day -1. |
Palavras-Chave: |
Elongação; Elongation; Maize; Root system. |
Thesagro: |
Milho; Sistema Radicular. |
Categoria do assunto: |
-- |
Marc: |
LEADER 01791naa a2200217 a 4500 001 1077862 005 2009-08-24 008 1989 bl --- 0-- u #d 100 1 $aCAHN, M. D. 245 $aRelationship between root elongation rate and diameter and duration of growth of lateral roots of maize. 260 $c1989 520 $aThe objective of this work was to describe the relationship between elongation rate and diameter of maize roots and to estimate the length and growth duration of lateral roots of maize. Diameters and elongation rates of roots were measured in situ on plants grown 5 weeks in small rhizotrons under greenhouse conditions. At the end of the experimental period the roots were harvested and diameters of axile and lateral roots were measured. The frequency distribution of diameters of harvested roots was bimodal with a minimum at 0.6 mm; 97% of axile roots were larger than this value and 98% of the lateral roots were smaller. Root elongation per day increased as diameter increased but the slope of the relationship with lateral roots was about 2.5 times that with axile roots when separate linear regressions were fitted to the two populations. The length of lateral roots found on axillary roots between the base and about 30 cm from the apex was approximately 2.2 cm. All of the data was consistent with the hypothesis that the lateral roots grew for about 2.5 days and the ceased growing. The axillary roots continued to grow throughout the experimental period at a rate of about 3 cm day -1. 650 $aMilho 650 $aSistema Radicular 653 $aElongação 653 $aElongation 653 $aMaize 653 $aRoot system 700 1 $aZOBEL, R. W. 700 1 $aBOULDIN, D. R. 773 $tPlant and Soil$gv. 119, n. 2, p. 271-279, 1989.
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Embrapa Meio Norte / UEP-Parnaíba (CPAMN-UEPP) |
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Registro Completo
Biblioteca(s): |
Embrapa Solos. |
Data corrente: |
12/08/2015 |
Data da última atualização: |
28/01/2016 |
Tipo da produção científica: |
Artigo em Periódico Indexado |
Circulação/Nível: |
A - 1 |
Autoria: |
HONG, J.; GRUNWALD, S.; VASQUES, G. M. |
Afiliação: |
JINSEOK HONG, EAST TENNESSEE STATE UNIVERSITY; SABINE GRUNWALD, UNIVERSITY OF FLORIDA; GUSTAVO DE MATTOS VASQUES, CNPS. |
Título: |
Soil phosphorus landscape models for precision soil conservation. |
Ano de publicação: |
2015 |
Fonte/Imprenta: |
Journal of Environmental Quality, Madison, v. 44, n. 3, p. 739-753, 2015. |
DOI: |
10.2134/jeq2014.09.0379 |
Idioma: |
Inglês |
Conteúdo: |
Phosphorus (P) enrichment in soils has been documented in the Santa Fe River watershed (SFRW, 3585 km2) in north-central Florida. Yet the environmental factors that control P distribution in soils across the landscape, with potential contribution to water quality impairment, are not well understood. The main goal of this study was to develop soil-landscape P models to support a "precision soil conservation" approach combining fine-scale (i.e., site-specific) and coarse-scale (i.e., watershed-extent) assessment of soil P. The specific objectives were to: (i) identify those environmental properties that impart the most control on the spatial distribution of soil Mehlich-1 extracted P (MP) in the SFRW; (ii) model the spatial patterns of soil MP using geostatistical methods; and (iii) assess model quality using independent validation samples. Soil MP data at 137 sites were fused with spatially explicit environmental covariates to develop soil MP prediction models using univariate (lognormal kriging, LNK) and multivariate methods (regression kriging, RK, and cokriging, CK). Incorporation of exhaustive environmental data into multivariate models (RK and CK) improved the prediction of soil MP in the SFRW compared with the univariate model (LNK), which relies solely on soil measurements. Among all tested environmental covariates, land use and vegetation related properties (topsoil) and geologic data (subsoil) showed the largest predictive power to build inferential models for soil MP. Findings from this study contribute to a better understanding of spatially explicit interactions between soil P and other environmental variables, facilitating improved land resource management while minimizing adverse risks to the environment. MenosPhosphorus (P) enrichment in soils has been documented in the Santa Fe River watershed (SFRW, 3585 km2) in north-central Florida. Yet the environmental factors that control P distribution in soils across the landscape, with potential contribution to water quality impairment, are not well understood. The main goal of this study was to develop soil-landscape P models to support a "precision soil conservation" approach combining fine-scale (i.e., site-specific) and coarse-scale (i.e., watershed-extent) assessment of soil P. The specific objectives were to: (i) identify those environmental properties that impart the most control on the spatial distribution of soil Mehlich-1 extracted P (MP) in the SFRW; (ii) model the spatial patterns of soil MP using geostatistical methods; and (iii) assess model quality using independent validation samples. Soil MP data at 137 sites were fused with spatially explicit environmental covariates to develop soil MP prediction models using univariate (lognormal kriging, LNK) and multivariate methods (regression kriging, RK, and cokriging, CK). Incorporation of exhaustive environmental data into multivariate models (RK and CK) improved the prediction of soil MP in the SFRW compared with the univariate model (LNK), which relies solely on soil measurements. Among all tested environmental covariates, land use and vegetation related properties (topsoil) and geologic data (subsoil) showed the largest predictive power to build inferential models for soil M... Mostrar Tudo |
Palavras-Chave: |
Modelo de precisão. |
Thesagro: |
Conservação do solo; Fósforo. |
Thesaurus NAL: |
Phosphorus; Precision. |
Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
Marc: |
LEADER 02383naa a2200217 a 4500 001 2021794 005 2016-01-28 008 2015 bl uuuu u00u1 u #d 024 7 $a10.2134/jeq2014.09.0379$2DOI 100 1 $aHONG, J. 245 $aSoil phosphorus landscape models for precision soil conservation.$h[electronic resource] 260 $c2015 520 $aPhosphorus (P) enrichment in soils has been documented in the Santa Fe River watershed (SFRW, 3585 km2) in north-central Florida. Yet the environmental factors that control P distribution in soils across the landscape, with potential contribution to water quality impairment, are not well understood. The main goal of this study was to develop soil-landscape P models to support a "precision soil conservation" approach combining fine-scale (i.e., site-specific) and coarse-scale (i.e., watershed-extent) assessment of soil P. The specific objectives were to: (i) identify those environmental properties that impart the most control on the spatial distribution of soil Mehlich-1 extracted P (MP) in the SFRW; (ii) model the spatial patterns of soil MP using geostatistical methods; and (iii) assess model quality using independent validation samples. Soil MP data at 137 sites were fused with spatially explicit environmental covariates to develop soil MP prediction models using univariate (lognormal kriging, LNK) and multivariate methods (regression kriging, RK, and cokriging, CK). Incorporation of exhaustive environmental data into multivariate models (RK and CK) improved the prediction of soil MP in the SFRW compared with the univariate model (LNK), which relies solely on soil measurements. Among all tested environmental covariates, land use and vegetation related properties (topsoil) and geologic data (subsoil) showed the largest predictive power to build inferential models for soil MP. Findings from this study contribute to a better understanding of spatially explicit interactions between soil P and other environmental variables, facilitating improved land resource management while minimizing adverse risks to the environment. 650 $aPhosphorus 650 $aPrecision 650 $aConservação do solo 650 $aFósforo 653 $aModelo de precisão 700 1 $aGRUNWALD, S. 700 1 $aVASQUES, G. M. 773 $tJournal of Environmental Quality, Madison$gv. 44, n. 3, p. 739-753, 2015.
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