A carregar...
Publicação
Valorização de resíduos florestais na formulação de substratos orgânicos para cultivo sem solo
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 1.71 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
Este trabalho teve como objetivo avaliar a viabilidade da utilização de dois resíduos florestais, a falca e a casca de eucalipto, na formulação de substratos, para cultivo sem solo. Nos viveiros florestais são utilizadas, em substratos, materiais como a turfa, casca de pinheiro, granulado de esferovite e perlite, que apresentam algumas desvantagens. A falca e a casca de eucalipto, se usadas em alternativa, permitem reduzir a dependência de outros países, o consumo de recursos e o impacto ambiental.
Foram estudadas quatro matérias-primas: granulado de esferovite, perlite, falca (granulometria 10 mm) e casca de eucalipto (granulometria 10 mm). Foram formulados oito substratos, misturando duas proporções (15% e 30% em volume) de cada matéria-prima com turfa. Os substratos foram caracterizados analiticamente e testados em dois ensaios, um laboratorial com agrião-de jardim (Lepidium sativum L.) e outro num viveiro florestal com pinheiro-manso (Pinus pinea L.).
A adição de esferovite, perlite e falca melhorou as propriedades físicas da turfa, destacando-se o aumento do arejamento e a redução da contratilidade.
A falca e a casca de eucalipto apresentaram maior condutividade elétrica, devido à maior disponibilidade nutrientes, resultando em maiores concentrações de fósforo, potássio e manganês na parte aérea dos pinheiros-mansos. As elevadas concentrações de manganês poderão ter originado fitotoxicidade, uma vez que se encontraram associadas a um menor crescimento das plantas. Contudo, não foi detetada fitotoxicidade em agrião-de-jardim.
Os pinheiros-mansos do substrato com 30% casca de eucalipto apresentaram menor teor de azoto, possivelmente provocado pela sua imobilização no substrato, que terá influenciado negativamente o crescimento das plantas.
Os substratos com esferovite, perlite, 15% falca e 15% casca de eucalipto originaram pinheiros-mansos que, aos 6 meses, já cumpriam os requisitos de tamanho para a sua comercialização com menos de um ano (Decreto-Lei n.º 205/2003). A exceção foram as plantas dos substratos com 30% falca e 30% casca de eucalipto, porém estas continuariam a crescer até aos 12 meses e poderiam, ainda, vir a cumprir os requisitos.
The purpose of this study was to assess the feasibility of using two forestry residues, cork oak branch bark (falca) and eucalyptus bark, in the formulation of alternative substrates for soilless growing. In forest nurseries, materials such as peat, pine bark, expanded polystyrene (EPS) and perlite are used as substrates, but they show some disadvantages. Alternatively, cork oak branch bark and eucalyptus bark can reduce foreign dependency, resource consumption, and environmental impact. Four raw materials were studied: peat, EPS beads, perlite, cork oak branch bark (10 mm particle size) and eucalyptus bark (10 mm particle size). Eight substrates were formulated, mixing two proportions (15% and 30% by volume) of each of the raw materials with peat. The substrates were characterized analytically and submitted to assays, in the laboratory with garden cress (Lepidium sativum L.) and in the forest nursery with stone pine (Pinus pinea L.). The addition of EPS, perlite and cork oak branch bark improved the physical properties of peat, especially aeration increase and shrinkage reduction. Cork oak branch bark and eucalyptus bark showed higher electrical conductivity, due to the greater nutrient availability, resulting in higher concentrations of phosphorus, potassium, and manganese in the shoots of stone pines. High manganese concentrations may have caused phytotoxicity, as they were associated with a lower plant growth. However, no phytotoxicity was detected in garden cress. In substrate with 30% eucalyptus bark, stone pines showed lower nitrogen content, possibly caused by its immobilization in the substrate, which may have reduced plant growth. After 6 months, substrates with EPS, perlite, 15% cork oak branch bark and 15% eucalyptus bark, generated stone pines that already met marketing size requirements prescribed by law for plants under one year old (Decreto-Lei n.º 205/2003). This did not happen in substrates with 30% cork oak branch bark and 30% eucalyptus bark. In these substrates, however, plants would continue to grow until they were 12 months old and would possibly still meet these requirements.
The purpose of this study was to assess the feasibility of using two forestry residues, cork oak branch bark (falca) and eucalyptus bark, in the formulation of alternative substrates for soilless growing. In forest nurseries, materials such as peat, pine bark, expanded polystyrene (EPS) and perlite are used as substrates, but they show some disadvantages. Alternatively, cork oak branch bark and eucalyptus bark can reduce foreign dependency, resource consumption, and environmental impact. Four raw materials were studied: peat, EPS beads, perlite, cork oak branch bark (10 mm particle size) and eucalyptus bark (10 mm particle size). Eight substrates were formulated, mixing two proportions (15% and 30% by volume) of each of the raw materials with peat. The substrates were characterized analytically and submitted to assays, in the laboratory with garden cress (Lepidium sativum L.) and in the forest nursery with stone pine (Pinus pinea L.). The addition of EPS, perlite and cork oak branch bark improved the physical properties of peat, especially aeration increase and shrinkage reduction. Cork oak branch bark and eucalyptus bark showed higher electrical conductivity, due to the greater nutrient availability, resulting in higher concentrations of phosphorus, potassium, and manganese in the shoots of stone pines. High manganese concentrations may have caused phytotoxicity, as they were associated with a lower plant growth. However, no phytotoxicity was detected in garden cress. In substrate with 30% eucalyptus bark, stone pines showed lower nitrogen content, possibly caused by its immobilization in the substrate, which may have reduced plant growth. After 6 months, substrates with EPS, perlite, 15% cork oak branch bark and 15% eucalyptus bark, generated stone pines that already met marketing size requirements prescribed by law for plants under one year old (Decreto-Lei n.º 205/2003). This did not happen in substrates with 30% cork oak branch bark and 30% eucalyptus bark. In these substrates, however, plants would continue to grow until they were 12 months old and would possibly still meet these requirements.
Descrição
Mestrado em Engenharia Agronómica. Universidade de Lisboa, Instituto Superior de Agronomia
Palavras-chave
economia circular substratos alternativos falca cortiça casca de eucalipto bark-based substrate growing media waste valorization cork oak branch bark eucalyptus bark
Contexto Educativo
Citação
Santos, S.F.R. Valorização de resíduos florestais na formulação de substratos orgânicos para cultivo sem solo. Lisboa: ISA-Universidade de Lisboa, 2022. Dissertação de Mestrado