Biomassa e nutrição mineral de forrageiras cultivadas em solos do semiárido adubados com esterco Biomass and mineral nutrition of forage grown in the semi-arid soils fertilized with manure

A produção de biomassa e as absorções de N, P e K de quatro espécies forrageiras foram comparadas em três solos representativos da região semi-árida da Paraíba, cultivadas sem e com adubação orgânica. As espécies foram jureminha (Desmanthus virgatus), orelha-de-onça (Macroptilium martii), feijão-de-rolinha (Macroptilium lathyroides) e capim buffel (Cenchrus ciliaris); os solos foram Neossolo Flúvico, Neossolo Regolítico e Planossolo Háplico e a adubação foi realizada com esterco bovino (20 Mg ha-1) comparado com a testemunha. A adubação com esterco promoveu grandes incrementos na produção de biomassa e nas acumulações dos nutrientes, em todas as plantas e solos. O esterco parece ter suprido P às plantas em quantidades suficientes mas não de N e K, confirmando que é uma boa fonte do primeiro elemento. O feijão de rolinha e a orelha de onça tiveram as maiores capacidades de acumulação de biomassa, principalmente em resposta à adubação. O capim buffel atinge maiores teores e conteúdos de K na matéria seca que as leguminosas. Não houve correspondência entre a análise dos solos e sua capacidade de suprimento de nutrientes.Biomass production and N, P and K uptake by four forage species were compared in three soils from the semi-arid region of Paraíba, with or without organic manure. The species were three legumes (Desmanthus virgatus , Macroptilium martii and Macroptilium lathyroides) and one grass (Cenchrus ciliaris); the soils, a Fluvic Neosol, a Regolithic Neosol and Haplic Planosol; and cattle manure was applied at a dose equivalent to 20 Mg ha-1. Manure application resulted in large increases in biomass production and nutrient uptake, in all species and soils. Apparently, the manure supplied enough P but not enough N and K to the plants, confirming that it is a good source of the first nutrient. Macroptilium martii and Macroptilium lathyroides seem to be the highest biomass producers, mainly in response to fertilization. Cenchrus ciliaris had higher K concentrations and contents than the legumes, indicating a larger K absorption capacity. There was no correspondence between soil analysis and nutrient supplying capacity

Efeito residual da adubação orgânica sobre a produtividade de milho em sistema agroflorestal Residual effect of organic fertilization on maize yield in an agroforestry system

O objetivo deste trabalho foi estudar, ao longo de dois anos, o efeito residual da adubação orgânica com esterco ou biomassa de gliricídia sobre os nutrientes do solo e sobre a produtividade e acúmulo de nutrientes pelo milho cultivado isolado (SA) ou consorciado em aléias de gliricídia (CA). O trabalho foi desenvolvido em Esperança, PB instalado em parcelas subdivididas, arranjadas em blocos casualizados, em que os sistemas (CA) e (SA) corresponderam aos tratamentos principais e os tratamentos de adubação com esterco, gliricídia e as parcelas-controle, aos tratamentos secundários, com quatro repetições. A adubação com esterco demonstrou maior efeito residual sobre a produtividade do milho nas parcelas do tratamento SA. No sistema CA o efeito residual foi reduzido, provavelmente pela competição por água e nutrientes entre o milho e gliricídia, indicando maior necessidade de adubação neste tipo de sistema. Os teores de P, K, Ca e Mg do solo em ambos os sistemas e ao longo dos dois anos do estudo foram mais elevados nas parcelas adubadas com esterco.<br>The objective of the present study was to evaluate, during a period of two years, the residual effects of organic fertilization with animal manure or gliridicia prunings on the fertility of soil and on productivity and nutrient accumulation by maize cultivated either isolated (SA) or intercropped within alleys of gliricidia (CA). The study was conducted during 2006 and 2007 in the Centro Agroecológico São Miguel, headquarters of the NGO AS-PTA, in Esperança, PB, Brazil. The experiment was established in a split-plot design, arranged in randomized blocks, with the type of cropping system (SA or CA) as the main treatments and the organic fertilization (animal manure, gliricidia prunings or control plots) as the secondary treatments, with four replications. The organic fertilization with animal manure led to a residual effect increasing maize productivity during the two years, but the fertilization with gliricidia prunings had no residual effect. The residual effect on maize productivity was more pronounced in the SA plots, compared to the plots with gliricidia alleys (CA). Probably, the lower residual effect within the CA system was due to the competition between maize and gliricidia for resources (nutrients, water and light), which indicates the need for higher rates or more frequent fertilizer applications in these systems. The contents of P, K, Ca and Mg in the soil was higher in the plots that received animal manure within both types of cropping systems

The Severity of COVID-19 Affects the Plasma Soluble Levels of the Immune Checkpoint HLA-G Molecule

The non-classical histocompatibility antigen G (HLA-G) is an immune checkpoint molecule that has been implicated in viral disorders. We evaluated the plasma soluble HLA-G (sHLA-G) in 239 individuals, arranged in COVID-19 patients (n = 189) followed up at home or in a hospital, and in healthy controls (n = 50). Increased levels of sHLA-G were observed in COVID-19 patients irrespective of the facility care, gender, age, and the presence of comorbidities. Compared with controls, the sHLA-G levels increased as far as disease severity progressed; however, the levels decreased in critically ill patients, suggesting an immune exhaustion phenomenon. Notably, sHLA-G exhibited a positive correlation with other mediators currently observed in the acute phase of the disease, including IL-6, IL-8 and IL-10. Although sHLA-G levels may be associated with an acute biomarker of COVID-19, the increased levels alone were not associated with disease severity or mortality due to COVID-19. Whether the SARS-CoV-2 per se or the innate/adaptive immune response against the virus is responsible for the increased levels of sHLA-G are questions that need to be further addressed

The Interplay among Glucocorticoid Therapy, Platelet-Activating Factor and Endocannabinoid Release Influences the Inflammatory Response to COVID-19

COVID-19 is associated with a dysregulated immune response. Currently, several medicines are licensed for the treatment of this disease. Due to their significant role in inhibiting pro-inflammatory cytokines and lipid mediators, glucocorticoids (GCs) have attracted a great deal of attention. Similarly, the endocannabinoid (eCB) system regulates various physiological processes including the immunological response. Additionally, during inflammatory and thrombotic processes, phospholipids from cell membranes are cleaved to produce platelet-activating factor (PAF), another lipid mediator. Nonetheless, the effect of GCs on this lipid pathway during COVID-19 therapy is still unknown. This is a cross-sectional study involving COVID-19 patients (n = 200) and healthy controls (n = 35). Target tandem mass spectrometry of plasma lipid mediators demonstrated that COVID-19 severity affected eCBs and PAF synthesis. This increased synthesis of eCB was adversely linked with systemic inflammatory markers IL-6 and sTREM-1 levels and neutrophil counts. The use of GCs altered these lipid pathways by reducing PAF and increasing 2-AG production. Corroborating this, transcriptome analysis of GC-treated patients blood leukocytes showed differential modulation of monoacylglycerol lipase and phospholipase A2 gene expression. Altogether, these findings offer a breakthrough in our understanding of COVID-19 pathophysiology, indicating that GCs may promote additional protective pharmacological effects by influencing the eCB and PAF pathways involved in the disease course

Cu e Zn na cultura do sorgo cultivado em três classes de solos: I. Crescimento vegetativo e produção Cu and Zn in sorghum cultivated in three soil classes: I. Vegetative growth and yield

Os micronutrientes Cu e Zn são importantes para o bom desenvolvimento vegetativo e para a formação de grãos em cereais. Com o objetivo de avaliar o efeito da aplicação de Cu e Zn nos atributos de crescimento e na produção da cultura do sorgo realizou-se um experimento em ambiente protegido, no qual o delineamento foi em blocos casualizados, com a combinação de cinco doses de cobre (0, 0,26, 0,90, 1,54 e 1,80 mg kg-1) e cinco doses de zinco (0, 0,32, 1,1, 1,88 e 2,2 mg kg-1), combinadas na matriz Composto Central de Box, perfazendo 9 tratamentos, que foram aplicados em três classes de solo (Latossolo, Luvissolo e Neossolo), com 3 repetições. Avaliaram-se, aos 96 dias após a semeadura, os atributos de crescimento e a produção da cultura. A aplicação de cobre resultou em incrementos na área foliar, diâmetro do colmo, comprimento e diâmetro da panícula, matéria seca e na produção, o mesmo não ocorrendo para o zinco. As concentrações foliares de zinco indicaram interação negativa entre as doses aplicadas, enquanto entre os solos o Luvissolo foi o mais responsivo à aplicação dos nutrientes.<br>The micronutrients copper and zinc are important for good vegetative growth and for grain formation in cereals. An experiment was carried out aiming to evaluate the effect of copper and zinc application upon growth attributes of sorghum and upon its grain yield. A randomized block experimental design was used, with a combination of five doses of copper (0, 0.26, 0.90, 1.54 and 1.80 mg kg-1) and five doses of zinc (0, 0.32, 1.1, 1.88 and 2.2 mg kg-1) combined by Box Central Composite design, resulting in nine treatments which were applied in three soil classes (Latosol, Alfisol and Entisol), with three replications. Ninety six days after sowing, growth attributes and sorghum yield were determined. The copper application increased leaf area, stem diameter, panicle length and diameter, dry matter yield and grain yield, however the same results were not observed for zinc application. The foliar concentrations of copper and zinc presented negative interactions between the applied doses. Alfisol was the soil most influenced by nutrient application