Necessidade de calagem em solos tropicais: um estudo na savana amazônica brasileira

Liming positively impacts soil quality, such as increasing pH and nutrient availability. In the state of Roraima, arable soils, for the most part, are under the domain of the savannah biome, with an acidic pH and low sum of bases, conditioning agricultural use to investments in fertility correction. Thus, the study aimed to evaluate different limestone recommendation methods and their effects on the chemical characteristics of three soil classes, using corn as an indicator plant in pot cultivation. The lower doses were considered to neutralize exchangeable acidity, and the higher doses aimed at neutralizing exchangeable acidity and increasing calcium and magnesium levels. In the more clayey soil, the different doses of lime did not affect the initial production of dry matter; therefore, a method that guarantees the supply of calcium and magnesium to the crop, in addition to neutralizing the toxic forms of aluminum, is the most appropriate. In sandy soils with low buffering power, predominant in the savannah, the highest doses of limestone reduced dry matter production. In these soils, the method based on the neutralization of exchangeable aluminum was efficient in raising the pH and reducing the exchangeable Al3+, but it did not guarantee adequate levels of calcium and magnesium for the crop's needs. The results show the importance of an individualized approach in lime requirement determination for liming in Roraima soils.A calagem apresenta impactos positivos na qualidade dos solos, como o aumento do pH e na disponibilidade de nutrientes. No estado de Roraima, solos agricultáveis, em grande parte, estão sob domínios do bioma savana e apresentam pH ácido e distrofia, condicionando o uso agrícola a investimentos na correção da fertilidade. Assim, objetivou-se avaliar diferentes métodos de recomendação de calcário e seus efeitos nas características químicas de três tipos de solo, tendo o milho como planta indicadora em um cultivo em vasos. As menores doses consideraram a neutralização da acidez trocável e as maiores a neutralização da acidez trocável e o aumento dos níveis de cálcio e magnésio. No solo mais argiloso, as diferentes doses de calcário não afetaram a produção inicial de biomassa seca; dessa forma, um método que garanta o fornecimento de cálcio e magnésio para a cultura, além de neutralizar as formas tóxicas de alumínio, é o mais adequado. Nos solos mais arenosos e com baixo poder tampão, predominantes na savana, as maiores doses de calcário reduziram a produção de biomassa. Nesses solos, o método baseado na neutralização do alumínio trocável foi eficiente em elevar o pH e reduzir o Al trocável, mas não garantiu teores de cálcio e magnésio adequados para a necessidade da cultura. Os resultados obtidos evidenciam a importância de uma abordagem individualizada na determinação da necessidade de calagem para os solos de Roraima

Necessidade de calagem em solos tropicais: um estudo na savana amazônica brasileira

A calagem apresenta impactos positivos na qualidade dos solos, como o aumento do pH e na disponibilidade de nutrientes. No estado de Roraima, solos agricultáveis, em grande parte, estão sob domínios do bioma savana e apresentam pH ácido e distrofia, condicionando o uso agrícola a investimentos na correção da fertilidade. Assim, objetivou-se avaliar diferentes métodos de recomendação de calcário e seus efeitos nas características químicas de três tipos de solo, tendo o milho como planta indicadora em um cultivo em vasos. As menores doses consideraram a neutralização da acidez trocável e as maiores a neutralização da acidez trocável e o aumento dos níveis de cálcio e magnésio. No solo mais argiloso, as diferentes doses de calcário não afetaram a produção inicial de biomassa seca; dessa forma, um método que garanta o fornecimento de cálcio e magnésio para a cultura, além de neutralizar as formas tóxicas de alumínio, é o mais adequado. Nos solos mais arenosos e com baixo poder tampão, predominantes na savana, as maiores doses de calcário reduziram a produção de biomassa. Nesses solos, o método baseado na neutralização do alumínio trocável foi eficiente em elevar o pH e reduzir o Al trocável, mas não garantiu teores de cálcio e magnésio adequados para a necessidade da cultura. Os resultados obtidos evidenciam a importância de uma abordagem individualizada na determinação da necessidade de calagem para os solos de Roraima

Physiological quality in maize seeds using conventional methods and NIR spectroscopy

Maize is one of the most important cereals, and stands out for its wide genetic diversity, adaptation to the most diverse climate conditions, and being, both directly and indirectly, the most basic food source of man. Globally, production is dependent on seed quality. Known methodologies for evaluating seed quality require improvement in developing technologies capable of achieving, in less time, results for the targets under evaluation. The aim of this study, therefore, was to compare conventional vigour testing with the ability of NIR technology to classify the physiological quality of maize seeds, cv. DKB-290-HS. For the experiment, which was conducted in a completely randomised design (CRD), six Batches of 200 seeds were used, with four replications. Conventional methods of evaluating seed vigour were used in the study. For the evaluation using the near-infrared (NIR) method, the seeds were placed with the embryo facing the source of electromagnetic waves. The resulting spectra were analysed by the Pirouette software using the PLS-DA method. The conventional methods for vigour, and the NIR technique both efficiently detected the levels of physiological quality. NIR also revealed the differences between Batches, classifying the physiological quality of maize seeds, cv. DKB-290-HS, into different levels quickly and efficiently

Condições de cultivo e substratos para produção de mudas de couve-manteiga em clima Tropical

Determinar um sistema eficiente de produção de mudas, em estufas agrícolas e sobre malhas fotoconversoras, considerando ainda a qualidade de substratos disponíveis, é essencial à obtenção de cultivos produtivos e economicamente viáveis. Nesse contexto, objetivamos avaliar os efeitos de condições de cultivo e de substratos na produção de mudas de couve-manteiga em área de clima Tropical. Para isso, combinamos, em parcelas subdivididas arranjadas inteiramente ao acaso, cinco condições de cultivo (A1: estufa agrícola, A2: Chromatinet®35% vermelha, A3: Chromatinet®50% vermelha, A4: Chromatinet®35% prata e A5: Chromatinet®50% prata) a quatro substratos (S1: OrganoAmazon®, S2: OrganoAmazon® + PuroHumus®, S3: OrganoAmazon® + PuroHumus® + solo + esterco bovino e S4: OrganoAmazon® + PuroHumus® + solo + esterco bovino + casca de arroz carbonizada), e avaliamos os seus efeitos sobre as variáveis quantitativas e qualitativas das mudas. Identificamos que o uso associado entre Chromatinet®35% prata (A4) e o substrato S2 (OrganoAmazon® + PuroHumus®) promoveu as melhores condições para o crescimento das mudas de couve-manteiga nas condições tropicais do estudo. A estufa (A1), quando combinada ao substrato S4 (OrganoAmazon® + PuroHumus® + solo + esterco bovino + casca de arroz carbonizada), também favorece à a produção de mudas de couve. O substrato formulado com OrganoAmazon® + PuroHumus® + solo + esterco + CAC (S3) é uma alternativa para a produção de mudas de couve. As telas de coloração vermelha (A2 e A3) e o substrato OrganoAmazon® (S1) utilizados isoladamente não favoreceram a produção de mudas de couve-manteiga sob as condições de clima Tropical

CARACTERIZACIÓN FISIOLÓGICA DE SEMILLAS DE OCHO VARIEDADES DE AMARANTO (Amaranthus spp.) EN LA PROVINCIA DE COTOPAXI / PHYSIOLOGICAL CHARACTERIZATION OF SEEDS OF EIGHT VARIETIES OF AMARANTH (Amaranthus spp.) IN THE PROVINCE OF COTOPAXI

El amaranto es un cultivo de gran importancia en el Ecuador debido a sus características nutricionales y fisiológicas relevantes en la salud humana, atribuidas a la acción de fibras alimentarias, para garantizar su producción es necesario el uso de semillas certificadas, por ello el objetivo de esta investigación fue determinar el potencial fisiológico de semillas de ocho variedades de amaranto (Amaranthus spp.); Zelenaya Sosulka (T1), Bulava (T2), Diumovachka (T3), Kizliarets (T4), Fakel (T5), India (T6), Valentina (T7) y Kobaca (T8), a través de pruebas fisiológicas tales como: humedad de semilla, germinación estándar, tetrazolio, conductividad eléctrica, envejecimiento acelerado, prueba de frío, índice de velocidad de emergencia y materia seca. Todas las pruebas utilizadas determinaron el perfil fisiológico de las ocho variedades de amaranto (Amaranthus spp.), se determinó que T7 (Valentina) presentó un alto desempeño fisiológico, en los parámetros de vigor y viabilidad, seguido de T3 (Diumovachka) y T5 (Fakel), estas variedades presentaron un desempeño aceptable en calidad fisiológica de semilla, el desempeño de las demás semillas T1 (Zelenaya Sosulka), T2 (Bulava), T4 (Kizliarets), T6 (India) y T8 (Kobaca) se verificó que son inapreciables al aplicar las mismas pruebas fisiológicas

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research