4 results on '"Pacheco, Vacilania"'
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2. Extraction strategies and sample thickness for visualevaluation of soil structure
- Author
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Pacheco, Vacilania, Guimarães, Rachel Muylaert Locks, Tormena, Cássio Antonio, and Moraes, Moacir Tuzzin de
- Subjects
Latossolos ,Soil structure ,Soils - Sampling ,Agronomia ,CIENCIAS AGRARIAS::AGRONOMIA [CNPQ] ,Solos - Amostragem ,Soils - Quality ,Estrutura do solo ,Ferralsols ,Solos - Qualidade - Abstract
Conselho Nacional do Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) O objetivo deste trabalho foi a) avaliar se diferentes espessuras das amostras resultam em mudanças no índice de qualidade estrutural (Sq) do solo pelo método VESS b) testar diferentes ferramentas de extração de amostra para proceder a avaliação da Sq-VESS e c) avaliar diferentes estratégias de exposição dos agregados do solo durante a avaliação do VESS; em Latossolos argilosos basálticos. As avaliações da espessura das amostras foram feitas em áreas sob plantio direto em Guarapuava, Pato Branco e São Jorge do Ivaí. Em cada área foram retiradas dez amostras de 15 x 25 cm (largura e profundidade), com uma pá reta, nas espessuras: 5; 10; 15; 20 e 25 cm. As avaliações das ferramentas de extração foram realizadas em três áreas em Pato Branco, tomando dez amostras para cada uma das ferramentas: pá de corte; pá + marreta + madeira; pá de impacto; pá jardineira; forcado; motosserra e pá acoplada a um trator. Nos mesmos locais da avaliação das ferramentas, foram avaliadas três estratégias de desagregação: manual; golpear a pá com uma marreta; e golpear a pá no chão, totalizando 30 amostras. Foram avaliados o escore Sq e aspectos práticos na extração das amostras. As amostras com espessura de 5 cm apresentaram menor Sq devido a redução dos agregados pelo corte pela pá. Para amostras com espessura de 20 cm verificou-se maior dificuldade de extração. A extração de amostras de 10 cm apresentou maior praticidade quando comparada às de 15 cm (método padrão), pelo menor volume de solo extraído. Não foi possível avaliar o escore Sq nas amostras de espessura de 25 cm pela grande dificuldade de extração da amostra. A integridade das amostras é preservada com o uso de pá de impacto e da motosserra, enquanto que a pá acoplada ao trator produziu grande compactação nas laterais e na porção inferior da amostra. A utilização de pá+marreta+madeira causou desestruturação na porção superior da amostra. As ferramentas pá jardineira e forçado não possibilitaram a extração da amostra. Desagregar o solo realizando batidas na pá com a marreta ou no chão promoveu dispersão do solo e mistura das camadas. Os resultados sugerem que a extração de amostras com espessura de 10 cm também pode ser utilizada para obter o escore Sq. O melhor método para extração da amostra é com a pá de corte, a pá de impacto e a motosserra e; a técnica recomendada para a desagregação é a manual. The objective of this work was a) to evaluate whether different thicknesses of the samples result in changes in the structural quality index (Sq) of the soil by the VESS method b) to test different sample extraction tools to proceed with the evaluation of the Sq-VESS and c) to evaluate different exposure strategies of soil aggregates during VESS assessment; in basaltic clayey Oxisols. The thickness evaluations of the samples were made in areas under no-tillage in Guarapuava, Pato Branco and São Jorge do Ivaí. Ten samples of 15 x 25 cm (width and depth) were taken in each area, with a straight shovel, in thicknesses: 5; 10; 15; 20 and 25 cm. The assessments of the extraction tools were carried out in three areas in Pato Branco, taking ten samples for each of the tools: cutting shovel; shovel + mallet + wood; impact shovel; garden shovel; pitchfork; chainsaw and shovel attached to a tractor. In the same places where the tools were evaluated, three disaggregation strategies were evaluated: manual; striking the shovel with a sledgehammer; and to hit the shovel on the floor, totaling 30 samples. The Sq score and practical aspects of sample extraction were evaluated. Samples with a thickness of 5 cm showed lower Sq due to the reduction of aggregates by cutting through the shovel. For samples with a thickness of 20 cm, there was greater difficulty in extraction. Extracting 10 cm samples was more practical when compared to 15 cm samples (standard method), due to the smaller volume of soil extracted. It was not possible to evaluate the Sq score in 25 cm thick samples due to the great difficulty in extracting the sample. The integrity of the samples is preserved with the use of an impact shovel and chainsaw, while the blade coupled to the tractor produced great compaction on the sides and the lower portion of the sample. The use of shovel + mallet + wood caused disruption in the upper portion of the sample. The garden shovel and pitchfork tools did not allow sample extraction. Disaggregating the soil by tapping the shovel with the mallet or on the ground promoted soil dispersion and mixing of the layers. The results suggest that the extraction of samples with a thickness of 10 cm can also be used to obtain the Sq score. The best method for extracting the sample is with the cutting shovel, the impact shovel and the chainsaw and; the recommended technique for isaggregation is manual.
- Published
- 2020
3. Mineral and organic fertilizer in two Physalis species
- Author
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Ariati Ana Claudia, Pacheco Vacilania, Negri Rafaele Cristina, Gomes Izabela, Oliveira Marisa de Cacia, and Loss Edenes Maria Schroll
- Subjects
0106 biological sciences ,biology ,food and beverages ,04 agricultural and veterinary sciences ,engineering.material ,biology.organism_classification ,01 natural sciences ,Nutrient ,Human fertilization ,Productivity (ecology) ,Agronomy ,Dry weight ,040103 agronomy & agriculture ,engineering ,Physalis ,0401 agriculture, forestry, and fisheries ,Environmental science ,Fertilizer ,General Agricultural and Biological Sciences ,Organic fertilizer ,Poultry litter ,010606 plant biology & botany - Abstract
Physalis cultivation can be an alternative of extra income for small and medium producers, mainly with the use of materials available on the property that can replace chemical fertilizer. This study aimed to evaluate agronomic parameters of Physalis peruviana and P. pubescens submitted two different sources of fertilization - chemical and organic. We evaluated plant height, shoot dry mass, production/plant, fruits diameter and weight and productivity. The organic fertilization provided better results for vegetative parameters. Regarding production, fertilization resulted in increase in mass, with no significant difference between sources. In the production of fruits/plant we obtained 156.2 g, 274.6 and 355.5 g for unfertilized, chemical and organic fertilizers, respectively, without significant differences between species. The productivity estimates were 2,370, 1,831 and 1,041 kg ha-1, for organic, mineral and unfertilized treatments, respectively. These results demonstrate that organic fertilizer with poultry manure is the best alternative as a source of nutrients, which may result in gains to the producer by the use of originated waste from other activities, as well as lower environmental contamination, either by improper disposal of waste or the use of chemical fertilizers. Key words: Nitrogen, nutrition, poultry litter, production, Solanaceae
- Published
- 2017
- Full Text
- View/download PDF
4. The impacts of cover crop mixes on the penetration resistance model of an Oxisol under no-tillage.
- Author
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Moraes, Moacir Tuzzin de, Olbermann, Flavio José Rohden, Bonetti, João de Andrade, Pilegi, Luan Roberto, Costa, Marcos Vinícius Rampi, Pacheco, Vacilania, Rogers, Craig David, and Guimarães, Rachel Muylaert Locks
- Subjects
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COVER crops , *SOIL matric potential , *SOIL cohesion , *NO-tillage , *SOIL moisture , *WILD oat - Abstract
Soil penetration resistance is used as an indicator of mechanical resistance to root growth into the soil matrix. However, penetration resistance measured only under wet soil conditions may not identify the effects of cover crops on soil structure. We aimed to determine the impact of individual and mixes of cover crops on soil penetration resistance as a function of water content and bulk density in an Oxisol under no-tillage in southern Brazil. Six treatments of individual and mixed cover crops were tested: (i) black oat; (ii) ryegrass; (iii) forage radish; (iv) wheat; (v) Fibrous-rooted crop mix: with 80 % fibrous-rooted and 20 % tap-rooted plants; and (vi) Tap-rooted crop mix: 40 % fibrous-rooted and 60 % tap-rooted plants. Soil cores were collected from a depth of 0–0.10 and 0.10–0.20 m and soil penetration resistance was evaluated under four soil water matric potentials (−6, −33, −100, and −500 kPa). Soil penetration resistance (Q) data for each treatment were fitted as a function of bulk density (ρ) and water content (θ) [Q=f(ρ, θ)]. The soil penetration resistance model was a non-linear equation (i.e., a double power function, with a negative exponent for water content and a positive exponent for bulk density). Under a given combination of bulk density and water content values, soil penetration resistance was higher after single crops than crop mixes, indicating a crop-mediated soil strengthening process. The cover crop mixes increased the macroporosity, resulting in an adequate soil physical quality for successional crops such as soybean, although no differences were observed for cover crops at soil water matric potentials of −60 hPa and −330 hPa when soil penetration resistance was used as a static measurement. The modelling of the soil resistance to penetration, as a function of soil bulk density and soil water content, showed that cover crops changed soil cohesion and reduced the impact of drying on soil strength when compared to the single cropping systems, indicating that soil penetration resistance should be modelled under a broad range of water contents, instead of only under a specific soil water content, to quantify the impacts of cover crops on soil strength. • Soil penetration resistance curve gave deeper insight into physical changes than single measure. • Mixed cover crops-maintained soil strength despite changes in moisture and bulk density. • Crop diversity improved soil physical quality, reducing strength for root growth. • The use of a crop with taproot system changes the soil structure and strength model. • Soil penetration resistance should be modelled under a broad range of water contents. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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