Soil penetration resistance analysis by multivariate and geostatistical methods

The penetration resistance (PR) is a soil attribute that allows identifies areas with restrictions due to compaction, which results in mechanical impedance for root growth and reduced crop yield. The aim of this study was to characterize the PR of an agricultural soil by geostatistical and multivariate analysis. Sampling was done randomly in 90 points up to 0.60 m depth. It was determined spatial distribution models of PR, and defined areas with mechanical impedance for roots growth. The PR showed a random distribution to 0.55 and 0.60 m depth. PR in other depths analyzed showed spatial dependence, with adjustments to exponential and spherical models. The cluster analysis that considered sampling points allowed establishing areas with compaction problem identified in the maps by kriging interpolation. The analysis with main components identified three soil layers, where the middle layer showed the highest values of PR.La resistencia a la penetración (RP) es un atributo del suelo que permite identificar zonas con restricciones debido a la compactación, que se traduce en impedancia mecánica para el desarrollo de las raíces y en una menor productividad de los cultivos. El objetivo del presente trabajo fue caracterizar la RP de un suelo agrícola, mediante análisis geoestadístico y multivariado. El muestreo se realizó de manera aleatoria en 90 puntos, hasta una profundidad de 0,60 m. Se determinaron los modelos de distribución espacial de la RP y se delimitaron áreas con problemas de impedancia mecánica de las raíces. La RP presentó distribución aleatoria a 0,55 y 0,60 m de profundidad. La RP en las otras profundidades analizadas mostraron dependencia espacial, con ajustes a modelos exponenciales y esféricos. El análisis jerárquico que consideró puntos de muestreo, permitió establecer zonas con problemas de compactación, identificadas en los mapas obtenidos mediante interpolación por kriging. El análisis de componentes principales permitió identificar tres capas de suelo, donde la capa intermedia fue la que presentó los mayores valores de RP

Outcome in patients perceived as receiving excessive care across different ethical climates: a prospective study in 68 intensive care units in Europe and the USA

Purpose: Whether the quality of the ethical climate in the intensive care unit (ICU) improves the identification of patients receiving excessive care and affects patient outcomes is unknown. Methods: In this prospective observational study, perceptions of excessive care (PECs) by clinicians working in 68 ICUs in Europe and the USA were collected daily during a 28-day period. The quality of the ethical climate in the ICUs was assessed via a validated questionnaire. We compared the combined endpoint (death, not at home or poor quality of life at 1 year) of patients with PECs and the time from PECs until written treatment-limitation decisions (TLDs) and death across the four climates defined via cluster analysis. Results: Of the 4747 eligible clinicians, 2992 (63%) evaluated the ethical climate in their ICU. Of the 321 and 623 patients not admitted for monitoring only in ICUs with a good (n = 12, 18%) and poor (n = 24, 35%) climate, 36 (11%) and 74 (12%), respectively were identified with PECs by at least two clinicians. Of the 35 and 71 identified patients with an available combined endpoint, 100% (95% CI 90.0–1.00) and 85.9% (75.4–92.0) (P = 0.02) attained that endpoint. The risk of death (HR 1.88, 95% CI 1.20–2.92) or receiving a written TLD (HR 2.32, CI 1.11–4.85) in patients with PECs by at least two clinicians was higher in ICUs with a good climate than in those with a poor one. The differences between ICUs with an average climate, with (n = 12, 18%) or without (n = 20, 29%) nursing involvement at the end of life, and ICUs with a poor climate were less obvious but still in favour of the former. Conclusion: Enhancing the quality of the ethical climate in the ICU may improve both the identification of patients receiving excessive care and the decision-making process at the end of life

Development of Sclerotium rolfsii sclerotia on soybean, corn, and wheat straw, under different soil temperatures and moisture contents Desenvolvimento de escleródios de Sclerotium rolfsii em palhas de soja, milho e trigo, sob diferentes temperaturas e umidades do solo

The objective of this work was to evaluate the effect of moisture and temperature on the development of Sclerotium rolfsii on soybean, corn, and wheat straw. Wheat straw produced the lowest number of sclerotia. Intermediate soil moisture level (70% of field capacity), and temperatures ranging between 25-30ºC favored sclerotia development. No sclerotia were formed at temperatures between 30-35ºC, on any type of straw.<br>O objetivo deste trabalho foi avaliar o efeito da umidade e da temperatura do solo no desenvolvimento de Sclerotium rolfsii sobre palhas de soja, milho e trigo. A palha de trigo proporcionou a formação de menor quantidade de escleródios. Umidade do solo intermediária (70% da capacidade de campo) e temperaturas entre 25-30ºC favoreceram a formação de escleródios. Na faixa de 30-35ºC, nenhum escleródio foi produzido em qualquer tipo de palha

Oxisol resistence to penetration in no-till system after sowing Resistência de um latossolo vermelho distroférrico à penetração em sistema plantio direto após semeadura

If inappropriately conducted, management and sowing practices may compromise the environment and the profitability of the agricultural activity. The aim of this study was to analyze the furrow opener mechanisms action and the level of load applied to soil firming mechanism in no-till, on the Oxisol resistance to penetration during soybean sowing, under three soil moistures. The experiment was arranged in split-split plot design, in which the plots were composed by three soil moistures (23.8; 25.5 and 27.5% b.s.), two furrow opener mechanisms sub-plots (double disks and furrow plough) and the split-split plot of three levels of load applied to soil firming mechanism (12.2; 18.5 and 24.1 kPa), according to randomized blocks design, with three replications. The soil moisture provided different resistance behavior to penetration with the depth, on the seedbed, independently of the furrow opener and the level of load applied to soil firming mechanism. The furrow plough use provided less soil resistance to penetration when compared to the double disk furrow opener, on the seedbed, independently of the soil moisture and the level of load applied to soil firming mechanism. The pressure applied by soil firming mechanism of 18.5 kPa provided the lower resistance to penetration, when the furrow plough was used. The soil resistance to penetration was less on the sowing line than on between rows, with 20 cm deep.<br>Práticas de manejo e semeadura mal conduzidas podem comprometer o meio ambiente e a rentabilidade da atividade agrícola. O objetivo deste trabalho foi estudar a ação de mecanismos sulcadores e a pressão da roda compactadora de uma semeadora-adubadora em plantio direto, na resistência de um Latossolo Vermelho distroférrico à penetração (RP), durante a semeadura da soja, sob três teores de água do solo. O experimento foi desenvolvido em esquema de blocos casualizados, arranjado em esquema de parcelas subsubdivididas, sendo as parcelas constituídas de três teores de água do solo (23,8; 25,5 e 27,5% b.s.), as subparcelas de dois mecanismos sulcadores (discos duplos e haste sulcadora) e as subsubparcelas de três pressões da roda compactadora (12,2; 18,5 e 24,1 kPa), com três repetições. O teor de água do solo promoveu diferença na RP com a profundidade, no leito de semeadura, independentemente do sulcador e da pressão da roda compactadora. O uso de haste sulcadora proporcionou menor RP comparada com o sulcador disco duplo, no leito de semeadura, independentemente do teor de água e da pressão da roda compactadora. A pressão aplicada pela roda compactadora de 18,5 kPa proporcionou as menores resistências do solo à penetração, quando a haste sulcadora foi usado. A RP foi menor na linha de semeadura do que na entrefileiras, até 20 cm de profundidade