Duration of the effects of scarification and raised bed associated with vegetation cover on soybean yield on an Alfisol

O objetivo deste trabalho foi determinar o tempo de duração dos efeitos das intervenções mecânicas escarificação e camalhão no rendimento de grãos de soja (Glycine max) em um Planossolo, bem como avaliar, por meio de indicadores físicos, se o uso de plantas de cobertura no período do inverno aumenta a duração destes efeitos. O delineamento experimental foi de blocos ao acaso com quatro repetições. Foram avaliados dois fatores. O primeiro consistiu do tipo de preparo do solo: ES14, escarificação em novembro de 2014; ES15, escarificação em novembro de 2015; CA14, camalhão construído em novembro de 2014; e CA15, camalhão construído em novembro de 2015. O segundo consistiu do tipo de cobertura: pousio no inverno, aveia, azevém e trigo. De novembro de 2015 a abril de 2016, cultivou-se soja sob os diferentes preparos do solo. Foram avaliados densidade do solo, porosidade total, macroporosidade, microporosidade, condutividade hidráulica do solo saturado, resistência do solo à penetração mecânica e rendimento de grãos de soja. Não foi detectado efeito de plantas de cobertura, em um único ano de cultivo, na manutenção dos atributos físicos do solo. Alterações na densidade, na porosidade total e na resistência do solo à penetração, promovidas pela escarificação mecânica, são perceptíveis por no mínimo 18 meses. A persistência dessas modificações reflete no rendimento de grãos de soja na segunda safra.The objective of this work was to determine the duration of the effects of the mechanical interventions scarification and raised bed on soybean (Glycine max) grain yield on an Alfisol, as well as to evaluate, through physical indicators, if the use of cover plants during winter increases the duration of these effects. The experimental design was a complete randomized block with four replicates. Two factors were evaluated. The first consisted of types of soil preparation systems: SC14, scarification in November 2014; SC15, scarification in November 2015; RB14, raised bed built in November 2014; and RB15, raised bed built in November 2015. The second consisted of the type of cover crop used: winter fallow, oat, ryegrass, and wheat. From November 2015 to April 2016, soybean was cultivated under the different soil preparation systems. Soil density, total porosity, macroporosity, microporosity, soil saturated hydraulic conductivity, soil resistance to mechanical penetration, and soybean grain yield were evaluated. There was no effect of cover plants after one crop season on the maintenance of soil physical attributes. Changes in soil density, total porosity, and resistance to mechanical penetration, promoted by scarification, are noticeable up to at least 18 months. The continuance of these modifications reflects in soybean grain yield in the second harvest

Ocorrência de brusone e qualidade de grãos em arroz irrigado adubado com nitrogênio e silicatos

The objective of this work was to evaluate the effects of fertilization with nitrogen topdressing and silicates, as well as of the use of fungicides, on the occurrence of panicle blast, milling yield, and whole grains, vitreous grains, and chalky kernels in an irrigated rice cultivar sensitive to the disease. Two experiments were conducted in a randomized complete block design, in a 4×4×2 factorial arrangement, with four replicates: in experiment 1, four doses of nitrogen × four doses of calcium and magnesium silicate on soil × with and without fungicides; and, in experiment 2, four doses of nitrogen × four doses of potassium silicate applied on leaves x with and without fungicides. At the doses above 60 kg ha-1 nitrogen without fungicides, there was an increase in panicle blast severity, a decrease in the percentage of whole and vitreous grains, and an increase in chalky kernels and chalky area. The greatest effects of silicates occurred without fungicides. Fungicide use reduced the severity of blast in the panicles. Milling yield ranged from 60 to 70% in both experiments. The control of blast with fungicides maintains high rice grain quality, milling yield, and percentages of whole and vitreous grains.O objetivo deste trabalho foi avaliar os efeitos da adubação com nitrogênio em cobertura e silicatos, bem como da utilização de fungicidas, sobre a ocorrência de brusone nas panículas, a renda do benefício e os grãos inteiros, vítreos e gessados, em cultivar de arroz irrigado sensível à doença. Foram conduzidos dois experimentos em delineamento de blocos ao acaso, em arranjo fatorial 4×4×2, com quatro repetições: no experimento 1, quatro doses de nitrogênio × quatro doses de silicato de cálcio e magnésio via solo × com e sem uso de fungicidas; e, no experimento 2, quatro doses de nitrogênio × quatro doses de silicato de potássio via foliar × com e sem fungicidas. Nas doses acima de 60 kg ha-1 de nitrogênio sem fungicidas, houve aumento da severidade de brusone nas panículas, redução do percentual de grãos inteiros e vítreos, e aumento de grãos gessados e área gessada. Os maiores efeitos dos silicatos ocorreram sem aplicações de fungicidas. O uso de fungicidas reduziu a severidade de brusone nas panículas. A renda do benefício oscilou entre 60 e 70%, em ambos os experimentos. O controle da brusone com fungicidas mantém elevadas a qualidade de grãos do arroz, a renda do benefício e as percentagens de grãos inteiros e vítreos

Escarificação do solo e sulcadores em semeadora para cultivo de milho em Planossolos

The objective this work was to evaluate deep tillage and different furrow opener seeders for growing corn in Planosols. Two experiments were carried out in the field, in two different locations: Santa Maria and Formigueiro, in the state of Rio Grande do Sul, Brazil. A randomized complete block experimental design was used, with four replicates, and treatments of deep tillage (DP) and no‑till, using different seed‑furrow openers: shank (SH); shank plus furrow accommodation mechanism (SHA); double disk (DD); and notched disk (ND). In Santa Maria, the raised-bed treatment using shank was added (RBS). The following parameters were evaluated: soil bulk density, porosity, and macroporosity; soil penetration resistance (RP); root system distribution; and grain yield. In Formigueiro, the DP, SH, and SHA treatments resulted in lower bulk density and higher soil macroporosity in the 0.05–0.10 and 0,10–0.20-m soil depths. The RP was lower in the DP treatment and in the furrow of the SH treatment until 0.15 m, where roots developed better. Corn grain yield in Planosols is greater when sowing is carried out using raised bed, deep tillage, or no‑till using shank in the seeder.O objetivo deste trabalho foi avaliar a escarificação mecanizada do solo e diferentes sulcadores, em semeadora, para cultivo de milho em Planossolos. Dois experimentos foram realizados em campo, em dois locais: Santa Maria e Formigueiro, RS. Um delineamento experimental de blocos ao acaso foi utilizado, com quatro repetições e tratamentos de escarificação do solo (ESC) e semeadura direta, com os seguintes sulcadores: haste sulcadora (HS), haste sulcadora e mecanismo de acomodação do sulco (HAS), disco duplo desencontrado (DD) e disco ondulado (DO). Em Santa Maria, foi adicionado o tratamento semeadura em camalhão com haste (CA). Os seguintes parâmetros foram avaliados: densidade, porosidade e macroporosidade do solo; resistência do solo à penetração mecânica (RP); distribuição do sistema radicular; e produtividade de grãos. Em Formigueiro, os tratamentos ESC, HS e HAS resultaram em menor densidade e maior macroporosidade do solo, nas camadas de 0,05–0,10 e 0,10–0,20 m. A RP foi menor no tratamento ESC e no sulco da HS até 0,15 m, onde as raízes se desenvolveram melhor. A produtividade de grãos de milho em Planossolos é maior quando a semeadura é realizada sobre camalhão, solo escarificado ou semeadura direta, com haste sulcadora na semeadora

Wood-poly(furfuryl alcohol) prepreg : a novel, ecofriendly laminate composite

Prepregs are commonly fabricated with non-renewable petroleum-based materials. To reduce the impact of the manufacturing of these materials and to produce more sustainable prepregs, this research aims to manufacture poly(furfuryl alcohol)/wood veneer prepregs and their posterior molding in laminate composites. For this purpose, the vacuum infusion process was used to impregnate the wood veneers, and compression molding was applied to manufacture three- and four-layer laminate composites. Scanning electronic microscopy was used to evaluate the impregnation. the laminate manufacturing and differential scanning calorimetry were used to predict the shelf-life of the prepregs, Fourier-transform infrared was used to evaluate the induced hydrolysis resistance, and thermogravimetric analysis was used to determine the thermal degradation of the laminates. Moreover, water uptake and flexural, compressive, and tensile properties were evaluated. The kinetic models were effective and showed a shelf life for the laminates of approximately 30 days in storage at −7 °C, which is an interesting result for laminates with lignocellulosic materials. FTIR proved the laminates’ excellent resistance to hydrolysis. The water absorption, thermal stability, and mechanical properties did not differ as the amount of wood veneer increased, but these results were up to ~40% higher compared with unidirectional wood laminates found in the literature, which is probably linked to the excellent interface observed with SEM

Wood-Poly(furfuryl Alcohol) Prepreg: A Novel, Ecofriendly Laminate Composite

Prepregs are commonly fabricated with non-renewable petroleum-based materials. To reduce the impact of the manufacturing of these materials and to produce more sustainable prepregs, this research aims to manufacture poly(furfuryl alcohol)/wood veneer prepregs and their posterior molding in laminate composites. For this purpose, the vacuum infusion process was used to impregnate the wood veneers, and compression molding was applied to manufacture three- and four-layer laminate composites. Scanning electronic microscopy was used to evaluate the impregnation. the laminate manufacturing and differential scanning calorimetry were used to predict the shelf-life of the prepregs, Fourier-transform infrared was used to evaluate the induced hydrolysis resistance, and thermogravimetric analysis was used to determine the thermal degradation of the laminates. Moreover, water uptake and flexural, compressive, and tensile properties were evaluated. The kinetic models were effective and showed a shelf life for the laminates of approximately 30 days in storage at −7 ◦C, which is an interesting result for laminates with lignocellulosic materials. FTIR proved the laminates’ excellent resistance to hydrolysis. The water absorption, thermal stability, and mechanical properties did not differ as the amount of wood veneer increased, but these results were up to ~40% higher compared with unidirectional wood laminates found in the literature, which is probably linked to the excellent interface observed with SEM.info:eu-repo/semantics/publishedVersio

Sistemas de preparo do solo e de semeadura no rendimento de grãos de soja em área de várzea

RESUMO:A presença de camada compactada próxima à superfície do solo e a variabilidade das propriedades químicas do solo podem afetar o rendimento de grão de soja. Com o trabalho, objetivou-se avaliar a influência de sistemas de preparo do solo e de semeadura e de locais de cultivo (áreas de corte e aterro) no rendimento dessa cultura. O experimento foi realizado na área experimental de várzea da Universidade Federal de Santa Maria, nas safras 2013/14 e 2014/15. O delineamento foi blocos ao acaso, com quatro repetições. Os tratamentos foram arranjados em parcelas subdivididas. As parcelas principais foram: área de corte (A1) e área de aterro (A2). As subparcelas foram os tipos de preparo do solo e de semeadura: com escarificação do solo e semeadura utilizando disco duplo na semeadora (D1); sem escarificação do solo e semeadura utilizando haste sulcadora na semeadora (D2); sem escarificação do solo e semeadura utilizando disco duplo na semeadora (D3). A cultivar utilizada foi a BMX Tornado. O tratamento com escarificação e haste sulcadora reduziu a resistência do solo à penetração e proporcionou maior teor de Mg e S no tecido foliar na safra 2013/14; e de N, P, K, Ca, Mg e S, em 2014/15. Esse tipo de preparo de solo possibilita maior rendimento de grão de soja sem diferenças entre as áreas de corte e de aterro

Soil management and application of agricultural gypsum in a Planosol for soybean cultivation

<div><p>ABSTRACT: This study investigated the effects of soil management systems, tillage, and application of gypsum agricultural to soil, on soybean development in lowland areas. The experiment was carried out on an Alfisol in a randomized complete block design in a factorial arrangement. The two soil tillage practices were without deep tillage and with deep tillage. Gypsum treatments were no gypsum application, 500kg of gypsum ha-1, 1000kg of gypsum ha-1, and 1500kg of gypsum ha-1. Deep tillage resulted in less soil resistance to root penetration during ryegrass cultivation during the soybean offseason, 11 months after applying the management treatments, resulting in higher dry mass of ryegrass in the offseason and higher soybean yield in the following year.</p></div