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 | Acesso ao texto completo restrito à biblioteca da Embrapa Milho e Sorgo. Para informações adicionais entre em contato com cnpms.biblioteca@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Milho e Sorgo. |
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Data corrente: |
29/12/2001 |
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Data da última atualização: |
07/06/2018 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
ROSCOE, R.; BUURMAN, P.; VELTHORST, E. J.; VASCONCELLOS, C. A. |
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Afiliação: |
EMBRAPA-CNPMS. |
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Título: |
Soil organic matter dynamics in density and particle size fractions as revealed by the 13C/12C isotopic ratio in a cerrado's oxisol. |
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Ano de publicação: |
2001 |
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Fonte/Imprenta: |
Geoderma, Amsterdam, v. 104, p. 185-202, 2001. |
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Idioma: |
Inglês |
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Conteúdo: |
In order to better understand the dynamics of soil organic matter (SOM) in Oxisols and the impact of converting native cerrado (savannah) into pasture, we studied the dynamics of different physically separated SOM pools at different depths in a cerrado oxisol (Typic Haplustox), under natural conditions and after 23 years cultivated pasture (Brachiaria spp.) via the replacement of the native C (C3-derived) by pasture C (C4-derived). Organic C stocks of the original cerrado (15+/- 3 kg m-2) and pasture (17 +/- 3 kg m-2) were not significantly different, which was attributed to the high biomass production of the tropical grasses and the protective effects of the high clay content (> 800 g kg-2). We observed that 89-91% of the total organic C accumulated in the clay + silt fraction. The replacement of cerrado-derived C by pasture-derived C was in average 36%, 34%, and 19% for Ap, AB1, and Bw2 horizons, respectively, suggesting a fast turnover rate of organic C regardless of the high clay content. The replacement decreased in the order: free low-density organic matter (LDOM) > heavy fractions (sand, silt, clay) > occluded-LDOM. The lower replacement of the occluded-LDOM compared to the heavy fractions was attributed to protection inside aggregates and to a possible accumulation of C3-derived charcoal (black carbon). After 23 years of pasture, about 50% of the total organic C in the free-LDOM in the topsoil was still from cerrado, indicating that a significant part of this fraction was relatively recalcitrant. Charcoal fragments observed in the fraction suggested that the recalcitrance was probably due to charred material. MenosIn order to better understand the dynamics of soil organic matter (SOM) in Oxisols and the impact of converting native cerrado (savannah) into pasture, we studied the dynamics of different physically separated SOM pools at different depths in a cerrado oxisol (Typic Haplustox), under natural conditions and after 23 years cultivated pasture (Brachiaria spp.) via the replacement of the native C (C3-derived) by pasture C (C4-derived). Organic C stocks of the original cerrado (15+/- 3 kg m-2) and pasture (17 +/- 3 kg m-2) were not significantly different, which was attributed to the high biomass production of the tropical grasses and the protective effects of the high clay content (> 800 g kg-2). We observed that 89-91% of the total organic C accumulated in the clay + silt fraction. The replacement of cerrado-derived C by pasture-derived C was in average 36%, 34%, and 19% for Ap, AB1, and Bw2 horizons, respectively, suggesting a fast turnover rate of organic C regardless of the high clay content. The replacement decreased in the order: free low-density organic matter (LDOM) > heavy fractions (sand, silt, clay) > occluded-LDOM. The lower replacement of the occluded-LDOM compared to the heavy fractions was attributed to protection inside aggregates and to a possible accumulation of C3-derived charcoal (black carbon). After 23 years of pasture, about 50% of the total organic C in the free-LDOM in the topsoil was still from cerrado, indicating that a significant part of this fractio... Mostrar Tudo |
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Palavras-Chave: |
Carbono organico; Densidade; Factionation; Fragmentacao; Isotop; Organic carbon; Particlesize; Particula; Savanna. |
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Thesagro: |
Cerrado; Isótopo; Matéria Orgânica; Solo; Tamanho. |
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Thesaurus Nal: |
density; organic matter; soil. |
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Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
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Marc: |
LEADER 02624naa a2200361 a 4500
001 1485178
005 2018-06-07
008 2001 bl uuuu u00u1 u #d
100 1 $aROSCOE, R.
245 $aSoil organic matter dynamics in density and particle size fractions as revealed by the 13C/12C isotopic ratio in a cerrado's oxisol.$h[electronic resource]
260 $c2001
520 $aIn order to better understand the dynamics of soil organic matter (SOM) in Oxisols and the impact of converting native cerrado (savannah) into pasture, we studied the dynamics of different physically separated SOM pools at different depths in a cerrado oxisol (Typic Haplustox), under natural conditions and after 23 years cultivated pasture (Brachiaria spp.) via the replacement of the native C (C3-derived) by pasture C (C4-derived). Organic C stocks of the original cerrado (15+/- 3 kg m-2) and pasture (17 +/- 3 kg m-2) were not significantly different, which was attributed to the high biomass production of the tropical grasses and the protective effects of the high clay content (> 800 g kg-2). We observed that 89-91% of the total organic C accumulated in the clay + silt fraction. The replacement of cerrado-derived C by pasture-derived C was in average 36%, 34%, and 19% for Ap, AB1, and Bw2 horizons, respectively, suggesting a fast turnover rate of organic C regardless of the high clay content. The replacement decreased in the order: free low-density organic matter (LDOM) > heavy fractions (sand, silt, clay) > occluded-LDOM. The lower replacement of the occluded-LDOM compared to the heavy fractions was attributed to protection inside aggregates and to a possible accumulation of C3-derived charcoal (black carbon). After 23 years of pasture, about 50% of the total organic C in the free-LDOM in the topsoil was still from cerrado, indicating that a significant part of this fraction was relatively recalcitrant. Charcoal fragments observed in the fraction suggested that the recalcitrance was probably due to charred material.
650 $adensity
650 $aorganic matter
650 $asoil
650 $aCerrado
650 $aIsótopo
650 $aMatéria Orgânica
650 $aSolo
650 $aTamanho
653 $aCarbono organico
653 $aDensidade
653 $aFactionation
653 $aFragmentacao
653 $aIsotop
653 $aOrganic carbon
653 $aParticlesize
653 $aParticula
653 $aSavanna
700 1 $aBUURMAN, P.
700 1 $aVELTHORST, E. J.
700 1 $aVASCONCELLOS, C. A.
773 $tGeoderma, Amsterdam$gv. 104, p. 185-202, 2001.
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Embrapa Milho e Sorgo (CNPMS) |
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| Acesso ao texto completo restrito à biblioteca da Embrapa Arroz e Feijão. Para informações adicionais entre em contato com cnpaf.biblioteca@embrapa.br. |
Registro Completo
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Biblioteca(s): |
Embrapa Arroz e Feijão. |
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Data corrente: |
06/06/2013 |
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Data da última atualização: |
18/10/2013 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
A - 1 |
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Autoria: |
MONDO, V. H. V.; CICERO, S. M.; DOURADO-NETO, D.; PUPIM, T. L.; DIAS, M. A. N. |
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Afiliação: |
VITOR HENRIQUE VAZ MONDO, CNPAF; SILVIO MOURE CICERO, ESALQ; DURVAL DOURADO-NETO, ESALQ; TULIO LOURENÇO PUPIM, ESALQ; MARCOS ALTOMANI NEVES, ESALQ. |
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Título: |
Effect of seed vigor on intraspecific competition and grain yield in maize. |
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Ano de publicação: |
2013 |
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Fonte/Imprenta: |
Agronomy Journal, Madison, v. 105, n. 1, p. 222-228, 2013. |
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Idioma: |
Inglês |
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Conteúdo: |
High-vigor seeds result in faster emergence of seedlings and crop establishment than low-vigor seeds. Th ese characteristics could enhance plant competitive ability and could have direct eff ects on maize (Zea mays L.) grain yield. Th is study examined the hypothesis that seed vigor heterogeneity in maize seed lots could increase intraspecifi c competition and negatively aff ect crop grain yield. A 2-yr experiment was executed combining two hybrid maize seed lots, possessing high-vigor and low-vigor seeds, in seven diff erent distributions in the sowing row. Th e distributions of the plants originating from high- and low-vigor seeds were evaluated at harvest for dry mass accumulation, prolifi cacy, number of grains per row, number of rows per ear, 1000-grain mass, and grain yield. A replacement series design for data analysis of two homogeneous populations and fi ve seed mixture populations was applied. We concluded that, in plant populations originating from heterogeneous seed lots, intraspecifi c competition was intensifi ed, resulting in losses of dry mass accumulation and grain yield. Plants originating from low-vigor seeds had less competitive ability and reduced plant dry mass accumulation and grain yield than those originating from high-vigor seeds and were responsible for crop yield losses. Plants originating from high-vigor seeds had a dominant eff ect on those originating from low-vigor seeds and had no compensatory eff ects. Th e major production component aff ected by intraspecifi c competition was the number of grains per row. MenosHigh-vigor seeds result in faster emergence of seedlings and crop establishment than low-vigor seeds. Th ese characteristics could enhance plant competitive ability and could have direct eff ects on maize (Zea mays L.) grain yield. Th is study examined the hypothesis that seed vigor heterogeneity in maize seed lots could increase intraspecifi c competition and negatively aff ect crop grain yield. A 2-yr experiment was executed combining two hybrid maize seed lots, possessing high-vigor and low-vigor seeds, in seven diff erent distributions in the sowing row. Th e distributions of the plants originating from high- and low-vigor seeds were evaluated at harvest for dry mass accumulation, prolifi cacy, number of grains per row, number of rows per ear, 1000-grain mass, and grain yield. A replacement series design for data analysis of two homogeneous populations and fi ve seed mixture populations was applied. We concluded that, in plant populations originating from heterogeneous seed lots, intraspecifi c competition was intensifi ed, resulting in losses of dry mass accumulation and grain yield. Plants originating from low-vigor seeds had less competitive ability and reduced plant dry mass accumulation and grain yield than those originating from high-vigor seeds and were responsible for crop yield losses. Plants originating from high-vigor seeds had a dominant eff ect on those originating from low-vigor seeds and had no compensatory eff ects. Th e major production component aff ect... Mostrar Tudo |
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Palavras-Chave: |
Competencia intraespecífica. |
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Thesagro: |
Erva daninha; Milho; Semente; Zea mays. |
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Thesaurus NAL: |
Corn; Intraspecific competition. |
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Categoria do assunto: |
F Plantas e Produtos de Origem Vegetal |
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Marc: |
LEADER 02278naa a2200253 a 4500
001 1959487
005 2013-10-18
008 2013 bl uuuu u00u1 u #d
100 1 $aMONDO, V. H. V.
245 $aEffect of seed vigor on intraspecific competition and grain yield in maize.$h[electronic resource]
260 $c2013
520 $aHigh-vigor seeds result in faster emergence of seedlings and crop establishment than low-vigor seeds. Th ese characteristics could enhance plant competitive ability and could have direct eff ects on maize (Zea mays L.) grain yield. Th is study examined the hypothesis that seed vigor heterogeneity in maize seed lots could increase intraspecifi c competition and negatively aff ect crop grain yield. A 2-yr experiment was executed combining two hybrid maize seed lots, possessing high-vigor and low-vigor seeds, in seven diff erent distributions in the sowing row. Th e distributions of the plants originating from high- and low-vigor seeds were evaluated at harvest for dry mass accumulation, prolifi cacy, number of grains per row, number of rows per ear, 1000-grain mass, and grain yield. A replacement series design for data analysis of two homogeneous populations and fi ve seed mixture populations was applied. We concluded that, in plant populations originating from heterogeneous seed lots, intraspecifi c competition was intensifi ed, resulting in losses of dry mass accumulation and grain yield. Plants originating from low-vigor seeds had less competitive ability and reduced plant dry mass accumulation and grain yield than those originating from high-vigor seeds and were responsible for crop yield losses. Plants originating from high-vigor seeds had a dominant eff ect on those originating from low-vigor seeds and had no compensatory eff ects. Th e major production component aff ected by intraspecifi c competition was the number of grains per row.
650 $aCorn
650 $aIntraspecific competition
650 $aErva daninha
650 $aMilho
650 $aSemente
650 $aZea mays
653 $aCompetencia intraespecífica
700 1 $aCICERO, S. M.
700 1 $aDOURADO-NETO, D.
700 1 $aPUPIM, T. L.
700 1 $aDIAS, M. A. N.
773 $tAgronomy Journal, Madison$gv. 105, n. 1, p. 222-228, 2013.
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