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Abstract(s)
A oliveira é uma das mais importantes culturas da bacia do mediterrâneo, possuindo grande importância econômica para Portugal e sendo a região de trás-os-montes a segunda maior produtora. Para manter altas produções é necessário um solo fértil, sendo este apto a suprir as necessidades nutricionais da cultura. Diante disso, a microfauna do solo pode auxiliar por ser responsável pelos processos de mineralização e imobilização dos nutrientes. Um bom exemplo é a associação entre as raízes e um grupo de fungos, designados micorrizico. Nesse contexto tem surgido no mercado uma gama crescente de biofertilizantes comerciais. Com isso, o objetivo do estudo foi avaliar o efeito de uma micorriza comercial nas (i) propriedades do solo, em particular na biodisponibilidade dos nutrientes; (ii) na performance fotossintética; (iii) no estado nutricional das plantas durante a estação de crescimento; (iv) e na produção de matéria seca. O experimento foi conduzido nas estufas do Instituto Politécnico de Bragança (IPB), região nordeste de Portugal. Foram instalados sete tratamentos (testemunha; micorriza; 3% NPK; 3% NPK + 3% N, 3% NPK + 3% P, 3% NPK + 3% K, 3% NPK + micro) com três repetições em um delineamento inteiramente ao acaso utilizando mudas de oliveira de um ano. Durante a fase de crescimento, foi avaliada a performance fotossintética das plantas. As plantas foram destruídas um ano após a plantação e separadas em raizes, caules e folhas. Os componentes da planta foram secos em estufa, pesados, moidos e analisados para a composição elementar. A partir de três repetições de amostras de solos foram determinados diversos parâmetros da fertilidade. Não foram registradas diferenças entre os tratamentos para os parâmetros medidos de fluorescência da clorofila. Relativamente a biomassa, se observou variação significativa na raiz entre tratamentos. Para a micorriza, a concentração de fósforo foi significativamente mais elevada no caule e na raiz que nos outros tratamentos. Também se observou um aumento no pH em relação a micorriza. Na disponibilidade de fósforo e potássio no solo, a micorriza se equiparou aos tratamentos com adição daqueles elementos. Para a matéria orgânica, a micorriza registou valores equivalentes aos tratamentos que originaram os resultados mais elevados. Para a atividade fosfatase, a micorriza se destacou (487,51 μg nitrofenol g-1 h-1), apresentando o dobro do tratamento com adição de fósforo (280,70 μg nitrofenol g-1 h-1). Diante do exposto, a micorriza comercial pode ser um bom suplemento fertilizante já que contribuiu para manter os níveis nutricionais em valores satisfatórios.
The olive tree is one of the most important crops of the Mediterranean basin. It represents a great economic importance for Portugal, being Trás-os-Montes the second most important producing region of the country. For maintaining high levels of production, it is necessary to have a fertile soil, capable of fulfilling the nutritional needs of the crop. Microfauna of the soil can helps in this purpose, because it is responsible for organic matter mineralization and immobilization of the nutrients. A good example is the association between the roots and a type of fungi, named as mycorrhizal. In this context, a growing range of commercial biofertilizers has emerged on the market. Thus, the aim of the study was to evaluate the effect of a commercial mycorrhiza on: (i) soil properties, in particular on the bioavailability of the nutrients; (ii) photosynthetic performance of the young plants; (iii) their nutritional status during the growing season; and (iv) dry matter yield. The experiment was conducted in a greenhouse of the Polytechnic Institute of Bragança (IPB), located in the northeast region of Portugal. Seven treatments (control, mycorrhiza, 3% NPK; 3% NPK + 3% N, 3% NPK + 3% P, 3% NPK + 3% K, 3% NPK + micro) were arranged in a completely random design with three replicates. Young rooted plants (~20 cm height) were used in this study and grown in pots of 3 kg soil for a year. During the growing season, it was evaluated the photosynthetic performance of the plants. The plants were destroyed one year after had been plantated and separated into roots, stems and leaves. The plant’s parts were dried in an oven, weighted, ground and analyzed for the elemental composition. From a soil sample they were determined several soil properties. There were not detected significant differences among treatments on the photosynthetic performance of the plants. For the biomass, it was possible to record significant differences among treatments for the roots. Phosphorus concentrations in the stems and roots were significantly higher in Mycorrhiza treated plants than in the other treatments. In Mycorrhiza pots were recorded the higher pH values. Soil phosphorus and potassium availability in Mycorrhiza pots was similar to the treatments receiving an addition of those elements. Mycorrhiza gave soil organic matter values similar to the treatments which maximized this parameter. For the phosphatase activity, the mycorrhiza (487,51 μg nitrofenol g-1 h-1) showed twice the value of the treatment with phosphorus addition (280,70 μg nitrofenol g-1 h-1). In view of the above, the commercial mycorrhiza appears as a good fertilizer since it may contribute for the maintenance of the plants nutritional status at satisfactory levels.
The olive tree is one of the most important crops of the Mediterranean basin. It represents a great economic importance for Portugal, being Trás-os-Montes the second most important producing region of the country. For maintaining high levels of production, it is necessary to have a fertile soil, capable of fulfilling the nutritional needs of the crop. Microfauna of the soil can helps in this purpose, because it is responsible for organic matter mineralization and immobilization of the nutrients. A good example is the association between the roots and a type of fungi, named as mycorrhizal. In this context, a growing range of commercial biofertilizers has emerged on the market. Thus, the aim of the study was to evaluate the effect of a commercial mycorrhiza on: (i) soil properties, in particular on the bioavailability of the nutrients; (ii) photosynthetic performance of the young plants; (iii) their nutritional status during the growing season; and (iv) dry matter yield. The experiment was conducted in a greenhouse of the Polytechnic Institute of Bragança (IPB), located in the northeast region of Portugal. Seven treatments (control, mycorrhiza, 3% NPK; 3% NPK + 3% N, 3% NPK + 3% P, 3% NPK + 3% K, 3% NPK + micro) were arranged in a completely random design with three replicates. Young rooted plants (~20 cm height) were used in this study and grown in pots of 3 kg soil for a year. During the growing season, it was evaluated the photosynthetic performance of the plants. The plants were destroyed one year after had been plantated and separated into roots, stems and leaves. The plant’s parts were dried in an oven, weighted, ground and analyzed for the elemental composition. From a soil sample they were determined several soil properties. There were not detected significant differences among treatments on the photosynthetic performance of the plants. For the biomass, it was possible to record significant differences among treatments for the roots. Phosphorus concentrations in the stems and roots were significantly higher in Mycorrhiza treated plants than in the other treatments. In Mycorrhiza pots were recorded the higher pH values. Soil phosphorus and potassium availability in Mycorrhiza pots was similar to the treatments receiving an addition of those elements. Mycorrhiza gave soil organic matter values similar to the treatments which maximized this parameter. For the phosphatase activity, the mycorrhiza (487,51 μg nitrofenol g-1 h-1) showed twice the value of the treatment with phosphorus addition (280,70 μg nitrofenol g-1 h-1). In view of the above, the commercial mycorrhiza appears as a good fertilizer since it may contribute for the maintenance of the plants nutritional status at satisfactory levels.
Description
Dupla diplomação com a Universidade Tecnológica Federal do Paraná - UTFPR
Keywords
Olea europaea L. Nutrição de plantas Fertilidade do solo Fósforo lábi