Dose econômica de nitrogênio para fertirrigação da cultura do milho verde no semiárido brasileiro

The objective of this work was to determine the nitrogen rate for fertigation associated with the maximum productivity of green corn (Zea mays) with a lower production cost, in two harvest seasons in the Brazilian semiarid region. The experimental design was a randomized complete block with four replicates, and the treatments consisted of four N rates (0, 80, 160, and 240 kg ha-1) in form of urea, applied via drip irrigation. The used cultivar was the Bt Feroz hybrid. The evaluated characteristics were: number and mass of marketable ears, gross income, net income, and rate of return. The greatest amounts of marketable ears were reached with 152.52 kg ha-1 N in summer (41,183.84 ears per hectare) and 190.31 kg ha-1 N in winter (53,291.25 ears per hectare). In the two harvests, there was a variation in production costs between R$2,422.12 ha-1 and R$ 3,320.95 ha-1 without N and with 240 kg ha-1 N, respectively. The winter harvest showed higher productivity and profitability of green ears with fertigation with 160 kg ha-1 N. In the Brazilian semiarid, the maximum productivity of green corn with the lowest production cost is reached with fertigation with 90 kg ha-1 N, in both harvests.O objetivo deste trabalho foi determinar a dose de nitrogênio para fertirrigação associada à máxima produtividade de milho verde (Zea mays) com menor custo de produção, em duas safras agrícolas no semiárido brasileiro. O delineamento experimental foi em blocos ao acaso, com quatro repetições, e os tratamentos consistiram em doses de N (0, 80, 160 e 240 kg ha-1), na forma de ureia, via irrigação por gotejamento. A cultivar utilizada foi o híbrido Bt Feroz. As características avaliadas foram: número e massa de espigas comercializáveis, renda bruta, renda líquida e taxa de retorno. As maiores quantidades de espigas comercializáveis foram alcançadas com 152,52 kg ha-1 de N no verão (41.183,84 espigas por hectare) e 190,31 kg ha-1 de N no inverno (53.291,25 espigas por hectare). Nas duas safras, houve variação nos custos de produção entre R$2.422,12 ha-1 e R$ 3.320,95 ha-1 sem N e com 240 kg ha-1 de N, respectivamente. A safra de inverno apresentou maior produtividade e rentabilidade de espigas verdes com fertirrigação com 160 kg ha-1 de N. No semiárido brasileiro, a máxima produtividade de milho verde com menor custo de produção é alcançada com a fertirrigação com 90 kg ha-1 de N, em ambas as colheitas

Soil fertility impact on recruitment and diversity of the soil microbiome in sub-humid tropical pastures in Northeastern Brazil

Abstract Soil fertility is key point to pastures systems and drives the microbial communities and their functionality. Therefore, an understanding of the interaction between soil fertility and microbial communities can increase our ability to manage pasturelands and maintain their soil functioning and productivity. This study probed the influence of soil fertility on microbial communities in tropical pastures in Brazil. Soil samples, gathered from the top 20 cm of twelve distinct areas with diverse fertility levels, were analyzed via 16S rRNA sequencing. The soils were subsequently classified into two categories, namely high fertility (HF) and low fertility (LF), using the K-Means clustering. The random forest analysis revealed that high fertility (HF) soils had more bacterial diversity, predominantly Proteobacteria, Nitrospira, Chloroflexi, and Bacteroidetes, while Acidobacteria increased in low fertility (LF) soils. High fertility (HF) soils exhibited more complex network interactions and an enrichment of nitrogen-cycling bacterial groups. Additionally, functional annotation based on 16S rRNA varied between clusters. Microbial groups in HF soil demonstrated enhanced functions such as nitrate reduction, aerobic ammonia oxidation, and aromatic compound degradation. In contrast, in the LF soil, the predominant processes were ureolysis, cellulolysis, methanol oxidation, and methanotrophy. Our findings expand our knowledge about how soil fertility drives bacterial communities in pastures

III Livro de Resultados de Pesquisa do GRAED PUCPR: trabalhos científicos em análise econômica do direito

Trata-se de obra coletiva composta por trabalhos científicos de membros e parceiros do GRAED PUCPR, que se apresenta como mecanismo de promoção de pesquisas científicas na área de Análise Econômica do Direito. Para tanto, são consolidados comunicados científicos apresentados no III Encontro de Pesquisa do GRAED PUCPR, resultados do Programa Institucional de Bolsas de Iniciação Científica (PIBIC) realizados por membros do grupo e artigos científicos avaliados por pares e cujas pesquisas relacionam-se com os projetos do grupo

Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42·4% vs 44·2%; absolute difference -1·69 [-9·58 to 6·11] p=0·67; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5-8] vs 6 [5-8] cm H2O; p=0·0011). ICU mortality was higher in MICs than in HICs (30·5% vs 19·9%; p=0·0004; adjusted effect 16·41% [95% CI 9·52-23·52]; p<0·0001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0·80 [95% CI 0·75-0·86]; p<0·0001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status