Percorrer por autor "Domingues, Lucas da Silva"
A mostrar 1 - 5 de 5
Resultados por página
Opções de ordenação
- Edaphic Fauna Associated with Areas Managed under no-till with and without TerracesPublication . Stockmann, Inara de Souza; Tessaro, Dinéia; Domingues, Lucas da Silva; Silva, Jéssica Camile da; Zarzycki, Luis Felipe Wille; Kubiak, Ketrin Lorhayne; Tolfo, Erivelto FolhatoConservation soil management systems can promote beneficial changes in the edaphic fauna, which is important in improving and maintaining soil quality. Hence, this study aimed to evaluate the edaphic fauna in two areas with soils managed under no-till with and without terraces for four years. The edaphic fauna was evaluated by installing 32 pitfall trapsin each experimental plot. After seven days, the traps were removed, and the sampled individuals were classified at the level of major taxonomic groups. Collembola, Acari, Formicidae, Coleoptera, and Araneae were the most abundant in both study areas. The mean abundance of the order Coleoptera stood out in the no-till system with terraces in 2021, while the orders Collembola and Acari were more abundant without terraces in 2019 and 2021, and 2021 and 2022, respectively. There was a greater abundance of organisms for both areas in 2021, with significant equitability in the no-till system with terraces. Thus, the results showed that only some groups are positively affected by mechanical erosion control.
- Efeito de duas leonardites comerciais nas propriedades do solo, no estado nutricional e na produção de matéria seca de plantas jovens de oliveira cultivadas em vasosPublication . Almeida, Surian Fernanda; Arrobas, Margarida; Raimundo, Soraia; Domingues, Lucas da Silva; Rodrigues, M.A.A leonardite é um material orgânico fóssil que está a ser usado na preparação de produtos comerciais para aplicação ao solo, com objetivo de promover as condições de crescimento das plantas, integrados no conceito atual de bioestimulantes para as plantas. Neste trabalho, apresentam-se os resultados de duas experiências em vasos com oliveira em que se usaram duas leonardites comerciais e um corretivo orgânico em duas doses e uma modalidade testemunha. Em uma das experiências, estes materiais fertilizantes foram aplicados de forma isolada e numa segunda experiência as plantas receberam um suplemento de fertilização com um adubo mineral NPK. Na experiência sem fertilização mineral NPK, o corretivo orgânico aumentou a matéria seca das plantas, mas o mesmo não aconteceu com a aplicação das leonardites que não aumentaram a produção de matéria seca em comparação com a testemunha. A aplicação de NPK aumentou a produção de matéria seca em comparação com os tratamentos que não receberam fertilizante mineral. A concentração de azoto nos tecidos mostrou que as leonardites podem imobilizar azoto, devendo esse aspeto ser tido em conta na fertilização das culturas tratadas com estes produtos. O impacte das leonardites na concentração de outros nutrientes nos tecidos foi reduzido. O corretivo orgânico contribuiu para o aumento do teor de matéria orgânica no solo. Mais estudos devem ser conduzidos para avaliar de que forma as leonardites podem exercer efeitos positivos nos solos e nas plantas, de forma a serem um fator de produção com retorno para os produtores.
- Effect of a commercial mycorrhiza on soil nutrients bioavailability and growth of young olive trees grown in a pot experimentPublication . Piroli, Valkiria Luisa Borsa; Arrobas, Margarida; Domingues, Lucas da Silva; Rodrigues, M.A.Mycorrhizal colonization of plant roots may have several benefits to nutrients and water acquisition by plants. The aim of the study was the evaluation of the effect of a commercial mycorrhiza on: (i) soil properties, in particular on the bioavailability of the nutrients; (ii) the nutritional status of the olive plants during the growing season; and (iii) dry matter yield on olive plants. The experiment was conducted in pots in a greenhouse of the Polytechnic Institute of Bragança, located in the northeast of Portugal. Seven treatments (Control, Mycorrhiza + 3% NPK, 3% NPK; 3% NPK + 3% N, 3% NPK + 3% P, 3% NPK + 3% K, 3% NPK + micronutrients) were arranged as 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. The plants were destroyed one year after had been planted and separated into roots, stems and leaves. The plant’s parts were dried in an oven (70 ºC), weighted, ground and analyzed for the elemental composition. From a soil sample of each experimental unit they were determined several soil properties. Total (roots+stems+leaves) matter yield did not significantly vary with the fertilizer treatments. Phosphorus concentrations in the stems and roots were significantly higher in Mycorrhiza treated plants than in the other treatments. In Mycorrhiza pots there were recorded the higher pH values. Soil phosphorus and potassium availability in Mycorrhiza pots was similar to the treatments receiving an addition of these elements. Mycorrhiza gave soil organic matter values similar to the treatments producing the higher values. Regarding 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). Thus, the commercial mycorrhiza was able to maintain the plant nutritional status.
- Leonardites rich in humic and fulvic acids had little effect on tissue elemental composition and dry matter yield in pot-grown olive cuttingsPublication . Arrobas, Margarida; Almeida, Surian Fernanda; Raimundo, Soraia; Domingues, Lucas da Silva; Rodrigues, M.A.The use of humic substances in agriculture has increased in recent years, and leonardite has been an important raw material in the manufacture of commercial products rich in humic and fulvic acids. Leonardite-based products have been used to improve soil properties and to help plants cope with abiotic and biotic stresses. In this study, the effects of two commercial leonardites and an organic compost, in addition to a control treatment, were assessed for pot-grown olive plants over a period of fourteen months on soil properties, tissue elemental composition and dry matter yield (DMY). Three organic amendments were applied at single and double rates of that set by the manufacturer. The study was arranged in two experiments: one containing the seven treatments mentioned above and the other containing the same treatments supplemented with mineral nitrogen (N), phosphorus (P) and potassium (K) fertilization. Overall, organic compost increased soil organic carbon by ~8% over the control. In the experiment without NPK supplementation, N concentrations in shoots and P in roots were the highest for the compost application (leaf N 12% and root P 32% higher than in the control), while in the experiment with NPK supplementation, no significant differences were observed between treatments. Total DMY was ~10% higher in the set of treatments with NPK in comparison to treatments without NPK. Leonardites did not affect significantly any measured variables in comparison to the control. In this study, a good management of the majority of environmental variables affecting plant growth may have reduced the possibility of obtaining a positive effect on plant nutritional status and growth from the use of commercial leonardites. The leonardites seemed to have caused a slight effect on biological N immobilization. This is not necessarily an advantage or a drawback; it is rather a feature that must be understood to help farmers make better use of these products.
- Use of commercial mycorrhizal fungi in stress-free growing conditions of potted olive cuttingsPublication . Rodrigues, M.A.; Piroli, Luísa Borsa; Forcelini, Douglas; Raimundo, Soraia; Domingues, Lucas da Silva; Cassol, Luís César; Correia, Carlos M.; Arrobas, MargaridaBiofertilizers of mycorrhizal fungi have been mainly tested in nutrient-limited soils or harsh environmental conditions, which have helped to highlight their beneficial role in plant growth. However, their benefits in stress-free growing conditions have not yet been properly proven. In this work, a commercial mycorrhizal fungi, composed of 18 ecto and endomycorrhizal fungi, was tested in a pot experiment with young olive cuttings, under an experimental apparatus allowing the evaluation of dry matter yield and plant nutritional status after one and two years of growth. The results highlighted the role of the mycorrhiza in increasing P bioavailability, either evaluated by soil P labile fraction or through tissue P concentration. The role of mycorrhiza in increasing soil organic C was also relevant (7% higher than the control). Mycorrhiza had little effect on the uptake of other nutrients and on the alleviation of excessive levels of metals, in particular Fe, in the shoots. Instead, olive showed its own exclusion mechanisms, registering root Fe levels 50 times higher than in shoots. Mycorrhiza did not improve plant growth compared to the other fertilized treatments. The increase in plant dry matter observed in the mycorrhiza treatment in comparison to the control was probably due to the initial content of the commercial product of N, P and K (3% N, 3% P2O5 and 3% K2O). Under the conditions of this experiment, the farmer would not benefit from the use of this mycorrhizal fungi, but it nevertheless proved its value for agriculture, suggesting that commercial products should be targeted more towards specific purposes, than for generalized uses.