Association of tropical forage grasses in pastures: agronomic aspects that determine plant performance
Autor(a) principal: | |
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Data de Publicação: | 2023 |
Tipo de documento: | Tese |
Idioma: | eng |
Título da fonte: | Biblioteca Digital de Teses e Dissertações da USP |
Texto Completo: | https://www.teses.usp.br/teses/disponiveis/11/11139/tde-13042023-103333/ |
Resumo: | Botanical richness and diversity regulate many ecosystem functions and offer the opportunity for sustainable intensification of perennial pastures through simultaneous or partial cultivation of grasses in the same field, which can result in increased productivity, reduced fertilizer and pesticide inputs, and less influence of edaphoclimatic variations. However, the existing information is mostly directed to associations of annual temperate grasses or association between grasses and legumes, with little information for associations of tropical perennial forage grasses. In addition, many studies do not explore the \"how and why\" of the interactions and agronomic responses among plant species that make up the association. In this context, the general hypothesis of this study was that three species of tropical perennial forage grasses with complementary strategies of exploration of niches, above and below ground, cultivated in association and managed under moderate defoliation regime do not compete for resources (light and nitrogen) and have greater herbage production than the monocultures individually. The general objective was to describe the dynamics of agronomic performance of the three tropical perennial forage grasses cultivated in monoculture and association aiming to identify the interactions that shape the use of resources (light and nitrogen), a determinant aspect of the botanical proportion and productive performance in these pastures. The study was carried out in Piracicaba, São Paulo, Brazil. The treatments were Andropogon gayanus cv. Planaltina (andropogon grass), Panicum maximum cv. Massai (massai grass) and Brachiaria brizantha cv. BRS Piatã (piata grass) cultivated as monocultures and in association (the three grass species in equal proportions based on the number of viable seeds) with four replications. Defoliation management was common to all treatments and corresponded to a pre-cutting height of 35 cm and a post-cutting height of 17.5 cm. We also described the calibration of a DNA-chloroplast based method to determine whether the botanical proportion of root samples from DNA artificial mixtures of these grasses can be accurately estimated and applied the method to data collected in the field to determine below ground botanical proportion and its relationship to the corresponding above ground botanical proportion. The results indicated that the association was shaped by competition for light (little competition for nitrogen), with massai grass showing greater botanical proportion and productive performance. Including the monocultures, piata grass had the lowest number of cycles and the greatest herbage accumulation per cycle. On the other hand, andropogon grass, massai grass, and the association showed greater number of cycles with smaller herbage accumulation per cycle, resulting in similar total herbage production for all treatments. The functional traits of the grass species in monoculture indicated that massai grass has greater foliage angle and smaller leaf area index in the upper 10 cm, which resulted in a greater proportion of light in the vertical profile of the canopy, favoring rapid leaf elongation. The fact resulted in greater tiller population density, resulting in shading on the others two grass species in the association and causing competition for light. The results of the calibration method indicated that the below ground botanical proportion was accurately estimated, and there is a high correlation between below ground and above ground botanical proportion. In conclusion, the association presented a productive performance similar to the monocultures. The grass species functional traits are important predictors to explain resource acquisition strategies and should be considered when choosing grass species that will be used to compose new associations. |
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Association of tropical forage grasses in pastures: agronomic aspects that determine plant performanceAssociação de gramíneas forrageiras tropicais em pastagens: aspectos agronômicos que determinam o desempenho das plantasBotanical diversityCompetição por luzCompetition for lightDiversidade botânicaGrass mixtureIdentificação molecularMistura de gramíneasMolecular identificationMorfogêneseMorphogenesis. Root systemNitrogen statusSistema radicularStatus de nitrogênioBotanical richness and diversity regulate many ecosystem functions and offer the opportunity for sustainable intensification of perennial pastures through simultaneous or partial cultivation of grasses in the same field, which can result in increased productivity, reduced fertilizer and pesticide inputs, and less influence of edaphoclimatic variations. However, the existing information is mostly directed to associations of annual temperate grasses or association between grasses and legumes, with little information for associations of tropical perennial forage grasses. In addition, many studies do not explore the \"how and why\" of the interactions and agronomic responses among plant species that make up the association. In this context, the general hypothesis of this study was that three species of tropical perennial forage grasses with complementary strategies of exploration of niches, above and below ground, cultivated in association and managed under moderate defoliation regime do not compete for resources (light and nitrogen) and have greater herbage production than the monocultures individually. The general objective was to describe the dynamics of agronomic performance of the three tropical perennial forage grasses cultivated in monoculture and association aiming to identify the interactions that shape the use of resources (light and nitrogen), a determinant aspect of the botanical proportion and productive performance in these pastures. The study was carried out in Piracicaba, São Paulo, Brazil. The treatments were Andropogon gayanus cv. Planaltina (andropogon grass), Panicum maximum cv. Massai (massai grass) and Brachiaria brizantha cv. BRS Piatã (piata grass) cultivated as monocultures and in association (the three grass species in equal proportions based on the number of viable seeds) with four replications. Defoliation management was common to all treatments and corresponded to a pre-cutting height of 35 cm and a post-cutting height of 17.5 cm. We also described the calibration of a DNA-chloroplast based method to determine whether the botanical proportion of root samples from DNA artificial mixtures of these grasses can be accurately estimated and applied the method to data collected in the field to determine below ground botanical proportion and its relationship to the corresponding above ground botanical proportion. The results indicated that the association was shaped by competition for light (little competition for nitrogen), with massai grass showing greater botanical proportion and productive performance. Including the monocultures, piata grass had the lowest number of cycles and the greatest herbage accumulation per cycle. On the other hand, andropogon grass, massai grass, and the association showed greater number of cycles with smaller herbage accumulation per cycle, resulting in similar total herbage production for all treatments. The functional traits of the grass species in monoculture indicated that massai grass has greater foliage angle and smaller leaf area index in the upper 10 cm, which resulted in a greater proportion of light in the vertical profile of the canopy, favoring rapid leaf elongation. The fact resulted in greater tiller population density, resulting in shading on the others two grass species in the association and causing competition for light. The results of the calibration method indicated that the below ground botanical proportion was accurately estimated, and there is a high correlation between below ground and above ground botanical proportion. In conclusion, the association presented a productive performance similar to the monocultures. The grass species functional traits are important predictors to explain resource acquisition strategies and should be considered when choosing grass species that will be used to compose new associations.A riqueza e diversidade botânica regula muitas funções do ecossistema e oferece a oportunidade de intensificação sustentável das pastagens perenes por meio do cultivo simultâneo ou parcial de gramíneas no mesmo campo, o que pode resultar em aumento de produtividade, redução do uso de insumos como fertilizantes e pesticidas e menor influência de variações edafoclimáticas. Entretanto, as informações existentes sobre o tema são, em sua maioria, direcionadas para associações de gramíneas anuais de clima temperado ou associação de gramíneas e leguminosas, com poucas informações para associações apenas de gramíneas forrageiras perenes de clima tropical. Além disso, muitos estudos não exploram o como e o porquê das interações e respostas agronômicas encontradas entre as espécies de plantas componente da associação. Nesse contexto, a hipótese geral deste estudo foi que três espécies de gramíneas forrageiras tropicais perenes com estratégias complementares de exploração de nichos acima e abaixo do solo cultivadas em associação e manejadas sob regime de desfolhação moderado não competem por recursos (luz e nitrogênio) e têm produção de forragem superior à média das monoculturas. O objetivo geral foi descrever a dinâmica do desempenho agronômico de três espécies de gramíneas forrageiras tropicais perenes cultivadas em monocultura e associação, visando identificar as interações que moldam o uso de recursos (luz e nitrogênio), aspectos determinantes da proporção botânica de cada espécie na associação e desempenho produtivo nessas pastagens. O estudo foi realizado em Piracicaba, São Paulo, Brasil. Os tratamentos foram Andropogon gayanus cv. Planaltina (capim andropogon), Panicum maximum cv. Massai (capim massai) e Brachiaria brizantha cv. BRS Piatã (capim piata) cultivados em monocultivo e associação (as três espécies em proporções iguais com base no número de sementes viáveis) com quatro repetições. O manejo da desfolha foi comum a todos os tratamentos e correspondeu a uma alturas pré-corte de 35 cm e pós-corte 17.5 cm. Também é descrita a calibração de um método baseado em DNA-cloroplasto com objetivos de determinar se a proporção botânica de amostras de raízes de misturas artificiais dessas gramíneas pode ser estimada com precisão e o método aplicado em dados coletados em campo para determinar a proporção botânica abaixo do solo e sua relação com a correspondente proporção acima do solo. Os resultados indicaram que a associação foi moldada pela competição pela luz e pouca competição por nitrogênio, com o capim massai apresentando maior proporção botânica e desempenho produtivo. Incluindo as monoculturas, o capim piata apresentou menor número de ciclos e maior produção de forragem. Em contrapartida, o capim andropogon, o capim massai e a associação apresentaram maior número de ciclos com menor produção de forragem, resultando produção total de forragem semelhante para todos os tratamentos. Os traços funcionais das espécies em monocultivo indicaram que o capim massai possui maior ângulo de folhagem e menor índice de área foliar nos 10 cm superiores, o que resultou em maior proporção de luz no perfil vertical do dossel e favorecendo rápido alongamento foliar. O fato resultou em maior densidade populacional de perfilhos, favorecendo o sombreando das outras duas espécies na associação e causando competição por luz. Os resultados do método de calibração indicaram que a proporção botânica abaixo do solo foi estimada com precisão e que existe alta correlação com a proporção acima do solo. Como conclusão, a associação apresentou desempenho produtivo similar à média dos monocultivos e os traços funcionais das espécies foram importantes preditores para explicar as estratégias de aquisição de recursos, devendo ser considerados para a escolha de espécies que irão compor novas associações.Biblioteca Digitais de Teses e Dissertações da USPSilva, Sila Carneiro daSilva, Alex Marciano dos Santos2023-02-08info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdfhttps://www.teses.usp.br/teses/disponiveis/11/11139/tde-13042023-103333/reponame:Biblioteca Digital de Teses e Dissertações da USPinstname:Universidade de São Paulo (USP)instacron:USPLiberar o conteúdo para acesso público.info:eu-repo/semantics/openAccesseng2023-04-14T19:02:16Zoai:teses.usp.br:tde-13042023-103333Biblioteca Digital de Teses e Dissertaçõeshttp://www.teses.usp.br/PUBhttp://www.teses.usp.br/cgi-bin/mtd2br.plvirginia@if.usp.br|| atendimento@aguia.usp.br||virginia@if.usp.bropendoar:27212023-04-14T19:02:16Biblioteca Digital de Teses e Dissertações da USP - Universidade de São Paulo (USP)false |
dc.title.none.fl_str_mv |
Association of tropical forage grasses in pastures: agronomic aspects that determine plant performance Associação de gramíneas forrageiras tropicais em pastagens: aspectos agronômicos que determinam o desempenho das plantas |
title |
Association of tropical forage grasses in pastures: agronomic aspects that determine plant performance |
spellingShingle |
Association of tropical forage grasses in pastures: agronomic aspects that determine plant performance Silva, Alex Marciano dos Santos Botanical diversity Competição por luz Competition for light Diversidade botânica Grass mixture Identificação molecular Mistura de gramíneas Molecular identification Morfogênese Morphogenesis. Root system Nitrogen status Sistema radicular Status de nitrogênio |
title_short |
Association of tropical forage grasses in pastures: agronomic aspects that determine plant performance |
title_full |
Association of tropical forage grasses in pastures: agronomic aspects that determine plant performance |
title_fullStr |
Association of tropical forage grasses in pastures: agronomic aspects that determine plant performance |
title_full_unstemmed |
Association of tropical forage grasses in pastures: agronomic aspects that determine plant performance |
title_sort |
Association of tropical forage grasses in pastures: agronomic aspects that determine plant performance |
author |
Silva, Alex Marciano dos Santos |
author_facet |
Silva, Alex Marciano dos Santos |
author_role |
author |
dc.contributor.none.fl_str_mv |
Silva, Sila Carneiro da |
dc.contributor.author.fl_str_mv |
Silva, Alex Marciano dos Santos |
dc.subject.por.fl_str_mv |
Botanical diversity Competição por luz Competition for light Diversidade botânica Grass mixture Identificação molecular Mistura de gramíneas Molecular identification Morfogênese Morphogenesis. Root system Nitrogen status Sistema radicular Status de nitrogênio |
topic |
Botanical diversity Competição por luz Competition for light Diversidade botânica Grass mixture Identificação molecular Mistura de gramíneas Molecular identification Morfogênese Morphogenesis. Root system Nitrogen status Sistema radicular Status de nitrogênio |
description |
Botanical richness and diversity regulate many ecosystem functions and offer the opportunity for sustainable intensification of perennial pastures through simultaneous or partial cultivation of grasses in the same field, which can result in increased productivity, reduced fertilizer and pesticide inputs, and less influence of edaphoclimatic variations. However, the existing information is mostly directed to associations of annual temperate grasses or association between grasses and legumes, with little information for associations of tropical perennial forage grasses. In addition, many studies do not explore the \"how and why\" of the interactions and agronomic responses among plant species that make up the association. In this context, the general hypothesis of this study was that three species of tropical perennial forage grasses with complementary strategies of exploration of niches, above and below ground, cultivated in association and managed under moderate defoliation regime do not compete for resources (light and nitrogen) and have greater herbage production than the monocultures individually. The general objective was to describe the dynamics of agronomic performance of the three tropical perennial forage grasses cultivated in monoculture and association aiming to identify the interactions that shape the use of resources (light and nitrogen), a determinant aspect of the botanical proportion and productive performance in these pastures. The study was carried out in Piracicaba, São Paulo, Brazil. The treatments were Andropogon gayanus cv. Planaltina (andropogon grass), Panicum maximum cv. Massai (massai grass) and Brachiaria brizantha cv. BRS Piatã (piata grass) cultivated as monocultures and in association (the three grass species in equal proportions based on the number of viable seeds) with four replications. Defoliation management was common to all treatments and corresponded to a pre-cutting height of 35 cm and a post-cutting height of 17.5 cm. We also described the calibration of a DNA-chloroplast based method to determine whether the botanical proportion of root samples from DNA artificial mixtures of these grasses can be accurately estimated and applied the method to data collected in the field to determine below ground botanical proportion and its relationship to the corresponding above ground botanical proportion. The results indicated that the association was shaped by competition for light (little competition for nitrogen), with massai grass showing greater botanical proportion and productive performance. Including the monocultures, piata grass had the lowest number of cycles and the greatest herbage accumulation per cycle. On the other hand, andropogon grass, massai grass, and the association showed greater number of cycles with smaller herbage accumulation per cycle, resulting in similar total herbage production for all treatments. The functional traits of the grass species in monoculture indicated that massai grass has greater foliage angle and smaller leaf area index in the upper 10 cm, which resulted in a greater proportion of light in the vertical profile of the canopy, favoring rapid leaf elongation. The fact resulted in greater tiller population density, resulting in shading on the others two grass species in the association and causing competition for light. The results of the calibration method indicated that the below ground botanical proportion was accurately estimated, and there is a high correlation between below ground and above ground botanical proportion. In conclusion, the association presented a productive performance similar to the monocultures. The grass species functional traits are important predictors to explain resource acquisition strategies and should be considered when choosing grass species that will be used to compose new associations. |
publishDate |
2023 |
dc.date.none.fl_str_mv |
2023-02-08 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://www.teses.usp.br/teses/disponiveis/11/11139/tde-13042023-103333/ |
url |
https://www.teses.usp.br/teses/disponiveis/11/11139/tde-13042023-103333/ |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
|
dc.rights.driver.fl_str_mv |
Liberar o conteúdo para acesso público. info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Liberar o conteúdo para acesso público. |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.coverage.none.fl_str_mv |
|
dc.publisher.none.fl_str_mv |
Biblioteca Digitais de Teses e Dissertações da USP |
publisher.none.fl_str_mv |
Biblioteca Digitais de Teses e Dissertações da USP |
dc.source.none.fl_str_mv |
reponame:Biblioteca Digital de Teses e Dissertações da USP instname:Universidade de São Paulo (USP) instacron:USP |
instname_str |
Universidade de São Paulo (USP) |
instacron_str |
USP |
institution |
USP |
reponame_str |
Biblioteca Digital de Teses e Dissertações da USP |
collection |
Biblioteca Digital de Teses e Dissertações da USP |
repository.name.fl_str_mv |
Biblioteca Digital de Teses e Dissertações da USP - Universidade de São Paulo (USP) |
repository.mail.fl_str_mv |
virginia@if.usp.br|| atendimento@aguia.usp.br||virginia@if.usp.br |
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1809090676390887424 |