Condições físicas e mecânicas de um latossolo em sistema integrado de produção agropecuária

Detalhes bibliográficos
Ano de defesa: 2016
Autor(a) principal: Ambus, Jordano Vaz
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de Santa Maria
Brasil
Agronomia
UFSM
Programa de Pós-Graduação em Ciência do Solo
Centro de Ciências Rurais
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://repositorio.ufsm.br/handle/1/11743
Resumo: The integrated crop livestock systems are an important alternative to diversify production, increasing efficiency and autonomy of production systems. However, inadequate management of this stocking system promotes numerous negative consequences, especially on structural properties dependent on soil pore space, which can be limiting for both the development of plants and for system sustainability. However, there are indications that well-managed grazing systems can generate benefits to soil structure, due to the action of the plant root system that is positively stimulated after grazing. The hypothesis of this study is that moderate grazing promotes improvements in soil structural quality in this system. The objective of the study was to evaluate how different grazing levels affect selected soil physical and mechanical properties. The experiment consists of a 15-years old integrated crop livestock system, managed with (Glycine max) in the summer and (Avena strigosa, Schreb) + (Lolium multiflorum Lam.) in winter intended for continuous grazing of beef cattle. The treatments consisted of different grazing intensities, determined by sward height, namely: 0.10 m (heavy grazing), 0.30 m (moderate grazing) and an area as control (without grazing) in an experimental design of randomized blocks with three replications. Preserved-structure samples (volumetric rings) were collected in the 0-0.05, 0.05-0.10, and 0.10-0.20 m layers at the end of each cycle, soybeans and pasture, April and November 2015, respectively. Soil bulk density (Ds), total porosity (Pt), macroporosity (Ma), microporosity (Mi), air permeability (Ka), saturated hydraulic conductivity soil (Ks), preconsolidation pressure (σp), compression ratio (Ic), decompression coefficient (Cd) and soil cyclic loading test were determined. The results indicate that grazing increases the state of compaction of the soil surface, causing negative effects of the physical and mechanical properties. However, there is a mitigation of the effects if evaluated after the summer crop.