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Galectin-3 (Gal-3) is a β-galactoside-binding lectin expressed in cells of the placental microenvironment. This lectin is involved in various biological processes, such as modulation of the immune system and control of parasitic illness. Toxoplasma gondii infection can lead to congenital transmission and cause miscarriages, prematurity and fetal anomalies. However, little is known about the role of Gal-3 in T. gondii infection in the placental microenvironment. This study aimed to unravel the underlying mechanisms of Gal-3 during T. gondii infection. For this purpose, we promoted the knockdown of Gal-3 expression by using RNA interference (RNAi) in BeWo cells or by using a synthetic inhibitor (GB1107) in human villous explants. We showed that the decreased Gal-3 expression in BeWo cells and human villous explants increases the invasion and proliferation of T. gondii probably by downregulating MIF and IL6 levels, highlighting thus the role of this lectin in modulating the immune response. Collectively, our study reveals Gal-3 as a promising target protein during congenital toxoplasmosis.

O cultivo intensivo do melão é baseado em modelos convencionais de monocultivos, os quais podem utilizar de forma ineficiente os recursos naturais e, associados ao manejo inadequado, contribuir para alterações climáticas. O principal objetivo deste estudo foi modelar o estoque de carbono futuro em agroecossistemas no cultivo de meloeiro sob diferentes cenários climáticos. O estudo foi conduzido no Campo Experimental Bebedouro da Embrapa Semiárido, Petrolina/PE, em área cultivada com melão amarelo, cv. Gladial e foram considerados oito ciclos de cultivo. O delineamento experimental foi composto de dois tipos de manejo de solo (com e sem revolvimento), dois tratamentos utilizando adubos verdes compostos de 14 espécies com diferentes proporções de leguminosas, gramíneas e oleaginosas e a vegetação espontânea, contendo quatro repetições divididos em blocos casualizados. Após 70 dias de desenvolvimento as plantas foram cortadas e depositadas no solo. Dados de temperatura e precipitação foram adquiridos dos modelos climáticos BCC CSM, MIROC5, CESM1-BGC, IPSL CM5B LR e HADGEM2-AO, seguindo os cenários climáticos RCP 4.5 e 8.5. O estoque de carbono (C) foi estimado até o ano de 2071 usando o modelo RothC. O tratamento com predominância de leguminosas e sem revolvimento aumentou o estoque de C no solo independentemente do cenário climático. O revolvimento do solo não favoreceu o acúmulo de C, fazendo com que nenhum dos tratamentos alcançasse o mesmo estoque que a Caatinga. No cenário RCP 4.5 o modelo MIROC5 favoreceu o maior acúmulo de C no solo; já os menores estoques de C ocorreram nos modelos CESM1-BGC e IPSL CM5B LR sob o cenário RCP 8.5.

Global projections indicate that the demand for fresh water, energy, and food will increase significantly in the coming decades under the pressure of population growth, economic development, climate change, and other factors. Faced with this, technologies that promote sustainable development through the use of clean energy will be imperative. That way, this study aimed at evaluating the productive performance of biomass sorghum and cowpea cultivars in different cropping systems and planting seasons. The experiment was conducted at the Caatinga Experimental Field at Embrapa Semiarid, Petrolina—PE. Four cowpea (BRS Itaim, BRS Gurguéia, BRS Guariba, and BRS Carijó) and two biomass sorghum cultivars (BRS 716 and AGRI-002E) were used in intercropping and monoculture systems. The cultivars were sown during two different seasons: June (season 1—winter) and December (season 2—summer) of 2021. The biometric and productive parameters and land equivalent ratios (LERs) of sorghum and cowpea were evaluated. The data were subjected to multivariate analysis. The productive performance of biomass sorghum cultivars Agri-002E and BRS 716 was higher when planted in December, with an increase of 37% due to the planting season. Cowpea productivity was not influenced by sowing seasons or the cultivation system. Based on the calculation of efficient land use, the intercropping between biomass sorghum cultivar BRS 716 and cowpea cultivars BRS Gurguéia, BRS Guariba, and BRS Carijó was advantageous when compared to monocultures planted in the hottest season. This study showed the importance of cultivar selection, the planting time, and land use efficiency in intercropping systems.

ABSTRACT: This study aimed to determine the effect of Zn source and dietary level on intestinal myo-inositol hexakisphosphate (InsP6) disappearance, intestinal accumulation of lower InsP and myo-inositol (MI), prececal mineral digestibility, bone mineralization, and Zn status of broilers without and with exogenous phytase in the feed. Male Ross 308 broilers were allocated in groups of 10 to 8 treatments with 8 pens each. Experimental diets were fed from d 7 to d 28 and contained 33 mg/kg dry matter plant-intrinsic Zn. Experimental factors were phytase supplementation (0 or 750 FTU/kg) and Zn source (none [0 mg/kg Zn], Zn-sulfate [30 mg/kg Zn], Zn-oxide [30 mg/kg Zn]). Additional treatments with 90 mg/kg Zn as Zn-sulfate or Zn-oxide and phytase were included to test the effect of Zn level. No Zn source or Zn level effects were observed for ADG, feed conversion ratio, prececal P digestibility, intestinal InsP6 disappearance, and bone ash concentration. However, those measurements were increased by exogenous phytase (P

IntroductionToxoplasma gondii is the etiologic agent of toxoplasmosis, a disease that affects about one-third of the human population. Most infected individuals are asymptomatic, but severe cases can occur such as in congenital transmission, which can be aggravated in individuals infected with other pathogens, such as HIV-positive pregnant women. However, it is unknown whether infection by other pathogens, such as Trypanosoma cruzi, the etiologic agent of Chagas disease, as well as one of its proteins, P21, could aggravate T. gondii infection.MethodsIn this sense, we aimed to investigate the impact of T. cruzi and recombinant P21 (rP21) on T. gondii infection in BeWo cells and human placental explants.ResultsOur results showed that T. cruzi infection, as well as rP21, increases invasion and decreases intracellular proliferation of T. gondii in BeWo cells. The increase in invasion promoted by rP21 is dependent on its binding to CXCR4 and the actin cytoskeleton polymerization, while the decrease in proliferation is due to an arrest in the S/M phase in the parasite cell cycle, as well as interleukin (IL)-6 upregulation and IL-8 downmodulation. On the other hand, in human placental villi, rP21 can either increase or decrease T. gondii proliferation, whereas T. cruzi infection increases T. gondii proliferation. This increase can be explained by the induction of an anti-inflammatory environment through an increase in IL-4 and a decrease in IL-6, IL-8, macrophage migration inhibitory factor (MIF), and tumor necrosis factor (TNF)-α production.DiscussionIn conclusion, in situations of coinfection, the presence of T. cruzi may favor the congenital transmission of T. gondii, highlighting the importance of neonatal screening for both diseases, as well as the importance of studies with P21 as a future therapeutic target for the treatment of Chagas disease, since it can also favor T. gondii infection.

Silicate rock powder (SRP) restores the fertility of weathered soils. However, its slow nutrient release is a disadvantage for short-duration crops. Humic-like acids (HLAs) are plant biostimulants that enhance root development and nutrient uptake. This work evaluates the effects of the co-application of HLA extracted from a vermicompost and SRP on the nutrient uptake and growth of maize cultivated in weathered soil in Brazil. The chemical composition of HLA was assessed using Fourier-transform infrared spectroscopy and 13Carbon-nuclear magnetic resonance, revealing an overall characteristic of hydrophobicity. A preliminary trial with different HLA concentrations (0, 20, 40, 80, and 160 mg L−1) revealed that 40 mg L−1 HLA resulted in the highest increase in the root area, dry root weight, H+ efflux, and the number of lateral roots, compared with other concentrations. The main experiment using soil treated with SRP at different rates (0, 600, 1200, 1800, and 2400 kg ha−1) showed that the co-application of SRP and HLA caused a significant difference in the root and total plant weights, compared with the sole SRP application. Furthermore, it increased the nutrient content of the plants. These effects are mainly because of increased proton pump activity and the hydrophobicity of HLA.

An efficient organic cultivation can be a viable strategy to enhance the sustainability of the melon production chain. This study aimed to assess the physiological and productive responses, as well as the post-harvest quality, of melon fruits, as a function of biofertilizer doses. The experiment followed a randomized blocks design, in a split-plot arrangement, with four replications. The treatments included six biofertilizer doses (0, 1, 2, 3, 4 and 5 L plant-1) as subplots and two melon hybrids (AC 154 and Royal Amália) as plots. The use of 3 L plant-1 cycle-1 of the biofertilizer increased the sugar content in the leaf tissue, improved the photosynthetic efficiency, enhanced the biochemical variables and provided higher yields, in addition to improving the fruit post-harvest quality of the tested hybrids.

The aim of this experiment is to evaluate the effects of adding porous zinc oxide, plant polyphenols, and their combination to diets without antibiotics and high-dose zinc oxide on the growth performance, diarrhea incidence, intestinal morphology, and microbial diversity of weaned piglets. A total of 150 Duroc × Landrace × Large White weaned piglets were allocated to one of five diets in a randomized complete block design with six replicates and five piglets per replicate. The experimental period was 42 d, divided into two feeding stages: pre-starter (0–14 d) and starter (14–42 d). In the pre-starter stage, the negative control group (NC) was fed a basal diet, the positive control group (PC) was fed a basal diet with 2000 mg/kg of zinc oxide, the porous zinc oxide group (PZ) was fed a basal diet with 500 mg/kg of porous zinc oxide, the plant polyphenol group (PP) was fed a basal diet with 1500 mg/kg of plant polyphenols, and the combination group (PZ + PP) was fed a basal diet with 500 mg/kg of porous zinc oxide and 1500 mg/kg of plant polyphenols. In the starter stage, the NC, PC, and PZ groups were fed a basal diet, while the PP and PZ + PP groups were fed a basal diet with 1000 mg/kg of plant polyphenols. The results showed that, (1) compared with the PZ group, adding plant polyphenols to the diet showed a trend of increasing the ADFI of weaned piglets from 14 to 28 d (p = 0.099). From days 28 to 42 and days 0 to 42, porous zinc oxide and the combination of porous zinc oxide and plant polyphenols added to the control diet improved the FCR to the level observed in pigs fed the PC diet. (2) Dietary PZ + PP tended to increase the jejunal villus height (VH) of weaned piglets (p = 0.055), and significantly increased the villus-height-to-crypt-depth ratio compared to the NC group (p < 0.05). (3) Compared with the NC group, PZ supplementation decreased the relative abundance of Firmicutes and increased the relative abundance of Bacteroidetes, and the relative abundance of Lactobacillus in the PZ and PZ + PP groups were both increased. In conclusion, porous zinc oxide and plant polyphenols may have synergistic effects in modulating intestinal health in weaned piglets and be a potential alternative to high-dose zinc oxide.

A adubação verde é uma técnica de manejo do solo que proporciona diversos benefícios aos agroecossistemas, melhorando a qualidade química, física e biológica do solo e permitindo que eles forneçam diferentes serviços ecossistêmicos. Assim, o objetivo do trabalho foi selecionar adubos verdes para compor agroecossistemas multifuncionais que prestem serviços ecossistêmicos em ambiente semiárido, por meio da adição de biomassa, C e N e da ciclagem de nutrientes. Para isso, foram avaliados, em dois ciclos de cultivo, 29 tratamentos utilizandose 14 espécies de leguminosas, oleaginosas e gramíneas, distribuídas em cultivos solteiros e consorciados. Setenta dias após a semeadura, os adubos verdes foram cortados e coletaram-se amostras das partes aérea e radicular, nas quais foram avaliadas a produção de biomassa fresca e seca e os teores de N, P, K, Ca, Mg e S. Os teores de C e a biomassa proveniente de rizodeposição foram estimados. Com esses dados, foram calculados os acúmulos dos nutrientes na biomassa aérea e radicular. Os dados foram comparados por meio de estatística descritiva e multivariada. Existe uma relação positiva entre o número crescente de espécies utilizadas em consórcio e a maior produção de biomassa aérea e radicular, favorecendo o aumento da capacidade do agroecossistema na prestação de serviços de provisão e de regulação, este último associado às medidas de mitigação das mudanças climáticas, o que evidencia a importância da biodiversidade.

Considerando a Biblioteca Universitária como um espaço de aprendizagem e que o bibliotecário deve acompanhar os processos de ensino e aprendizagem e a sua aplicabilidade nos serviços de referência, ou seja, no desenvolvimento da Competência em Informação como parte integrante do ambiente pedagógico, o presente artigo tem como objetivo estudar a respeito da relevância que a Biblioteca Universitária desempenha no papel de mediadora do processo de ensino aprendizagem na educação superior. Busca-se compreender o papel do bibliotecário no contexto do processo de aprendizagem e do seu papel pedagógico na oferta de programas de Competência em Informação, por isso, trata-se de uma pesquisa de cunho bibliográfico e descritivo, com abordagem qualitativa. A partir da análise bibliográfica pode-se concluir que os profissionais bibliotecários precisam desenvolver competências pedagógicas para a aplicabilidade das metodologias ativas de ensino e aprendizagem, em seus programas de competência em informação alinhados as propostas educacionais ofertadas nas salas de aulas das IES, de forma eficiente e buscando aperfeiçoar seu perfil, sempre de acordo com as mudanças que vêm ocorrendo na oferta da educação. O artigo também traz exemplos de metodologias ativas, bem como possíveis meios de aplicabilidade em atividades ofertadas pela BU’s, além de sugestões de publicações para aprofundamento no estudo de cada uma delas.

The conventional treatment of congenital toxoplasmosis is mainly based on the combination of sulfadiazine and pyrimethamine. However, therapy with these drugs is associated with severe side effects and resistance, requiring the study of new therapeutic strategies. There are currently many studies with natural products, including Copaifera oleoresin, showing actions against some pathogens, as Trypanosoma cruzi and Leishmania. In the present study, we investigated the effects of the leaf hydroalcoholic extract and oleoresin from Copaifera multijuga against Toxoplasma gondii in human villous (BeWo) and extravillous (HTR8/SVneo) trophoblast cells, as well as in human villous explants from third-trimester pregnancy. For this purpose, both cells and villous explants were infected or not with T. gondii, treated with hydroalcoholic extract or oleoresin from C. multijuga and analyzed for toxicity, parasite proliferation, cytokine and ROS production. In parallel, both cells were infected by tachyzoites pretreated with hydroalcoholic extract or oleoresin, and adhesion, invasion and replication of the parasite were observed. Our results showed that the extract and oleoresin did not trigger toxicity in small concentrations and were able to reduce the T. gondii intracellular proliferation in cells previously infected. Also, the hydroalcoholic extract and oleoresin demonstrated an irreversible antiparasitic action in BeWo and HTR8/SVneo cells. Next, adhesion, invasion and replication of T. gondii were dampened when BeWo or HTR8/SVneo cells were infected with pretreated tachyzoites. Finally, infected and treated BeWo cells upregulated IL-6 and downmodulated IL-8, while HTR8/SVneo cells did not change significantly these cytokines when infected and treated. Finally, both the extract and oleoresin reduced the T. gondii proliferation in human explants, and no significant changes were observed in relation to cytokine production. Thus, compounds from C. multijuga presented different antiparasitic activities that were dependent on the experimental model, being the direct action on tachyzoites a common mechanism operating in both cells and villi. Considering all these parameters, the hydroalcoholic extract and oleoresin from C. multijuga can be a target for the establishment of new therapeutic strategy for congenital toxoplasmosis.

Le zinc et le cuivre sont des éléments-traces métalliques (ÉTM) qui peuvent présenter à plus ou moins long terme un risque environnemental pour les sols agricoles sur lesquels sont valorisées les déjections porcines. Ces ÉTM sont essentiels pour la croissance et la santé des porcs en élevage, ils sont donc ajoutés dans l’aliment sous forme de supplémentation. Cependant, du fait de leur faible taux de rétention chez le porc, ils se retrouvent très majoritairement excrétés dans les déjections. De plus, ce sont des ressources minérales naturelles limitées. Il est alors essentiel de caractériser leurs flux le long du continuum aliments-déjections-traitements-sols afin de maîtriser au mieux leur utilisation. Un état des lieux des connaissances sur ces flux montre que l’alimentation est le principal levier pour limiter les rejets de ces ETM vers l’environnement. La réglementation européenne fixe actuellement des teneurs limites des aliments en zinc et en cuivre (e.g. pour un porc en engraissement, 120 et 25 mg.kg- 1 MS respectivement). Le traitement des déjections est un second levier pour optimiser la valorisation de ces effluents d’élevage et mieux gérer la redistribution de ces ÉTM sur les sols, en les concentrant dans certains produits plus facilement exportables vers des zones en déficit. Une meilleure connaissance de leur forme chimique tout au long de la filière est aussi nécessaire pour mieux maîtriser leur devenir et préciser les risques pour l’environnement. Des recherches restent nécessaires pour affiner les stratégies d’apport dans les aliments, tout en conservant les performances et la santé des animaux et en prenant en compte les différentes modalités de gestion des effluents dans le cadre d’une bioéconomie circulaire.

Abstract Congenital toxoplasmosis is represented by the transplacental passage of Toxoplasma gondii from the mother to the fetus. Our studies demonstrated that T. gondii developed mechanisms to evade of the host immune response, such as cyclooxygenase (COX)-2 and prostaglandin E2 (PGE2) induction, and these mediators can be produced/stored in lipid droplets (LDs). The aim of this study was to evaluate the role of COX-2 and LDs during T. gondii infection in human trophoblast cells and villous explants. Our data demonstrated that COX-2 inhibitors decreased T. gondii replication in trophoblast cells and villous. In BeWo cells, the COX-2 inhibitors induced an increase of pro-inflammatory cytokines (IL-6 and MIF), and a decrease in anti-inflammatory cytokines (IL-4 and IL-10). In HTR-8/SVneo cells, the COX-2 inhibitors induced an increase of IL-6 and nitrite and decreased IL-4 and TGF-β1. In villous explants, the COX-2 inhibitors increased MIF and decreased TNF-α and IL-10. Furthermore, T. gondii induced an increase in LDs in BeWo and HTR-8/SVneo, but COX-2 inhibitors reduced LDs in both cells type. We highlighted that COX-2 is a key factor to T. gondii proliferation in human trophoblast cells, since its inhibition induced a pro-inflammatory response capable of controlling parasitism and leading to a decrease in the availability of LDs, which are essentials for parasite growth.

Os Sistemas agroflorestais (SAFs) são sistemas de produção agrícola que atuem próximos a dinâmica da natureza. O objetivo desta pesquisa foi avaliar características químicas, físicas e microbiológicas de solos de SAF’s em três estágios sucessionais e em uma área controle (pastagem), localizadas em Brasília, Distrito Federal. O histórico da área foi elaborado a partir de informações coletadas em entrevista. Realizou-se análises químicas (pH, MO, C, N, C:N, P, K, Ca, Mg e Al), físicas (granulometria) e microbiológicas (glomalina facilmente extraível). Os dados foram analisados através de análise multivariadas e univariadas. A agrobiodiversidade vegetal foi de 19 espécies no SAF estabelecido, 11 no SAF em formação, 5 no SAF inicial e 2 na pastagem. Os SAFs estabelecido e em formação foram os que obtiveram o maior aumento progressivo de C, MO, K e Ca. Quanto maior o estágio sucessional, maior o grau de agregação e a distribuição dos agregados. Os solos de todos os SAFs e da pastagem apresentaram a glomalina, sendo sua maior concentração nos SAFs. Conclui-se que quanto maior o tempo de manejo, maiores serão as diferenças nas características químicas, físicas e microbiológicas do solo. A evolução temporal dos sistemas favorece para uma maior disponibilidade de nutrientes, aumento da atividade biológica e da capacidade de agregação, aumentando, consequentemente, a camada orgânica do solo, retendo mais carbono no sistema, gerando serviços ecossistêmicos e contribuindo para a atenuação dos efeitos danosos de processos agrícolas no solo e no ecossistema.

Soils attributes such as granulometry and density determine the distribution of pore size and condition physical and differentiated hydraulic behavior. Thus, knowing the characteristics of the soils allow the use of more adequate management techniques that lead to the improvement of the performance of the use of this resource. The aim of this study was to evaluate the diameters of granulometric fractions and the physical-hydric behavior of sandy soils from semiarid region of Brazil. Trenches were excavated to collect, describe, and characterize the morphology of soil samples. The soil bulk density, particle density, granulometry, water retention curve, total porosity and pore size distribution were evaluated. The textural difference among soil studied is expressed with greater emphasis on the amount of macropores, high retention micropores and cryptopores. Fine and very fine sand are the most impacted granulometric fractions increasing macroporosity and reducing high tension microporosity and cryptoporosity. Luvisol with predominance of silt and clay fractions, presents a greater risk of densification and erosion, thus the use of lower irrigation levels is recommended. Acrisols and Luvisol, with predominance of fine and very fine sand fractions, present similar conditions of macroporosity and cryptopores with a low textural gradient. Acrisols and Luvisol do not present major problems regarding the reduction of hydraulic conductivity along the profile. Lower irrigation levels with higher application frequency are suggested due to the low water retention capacity and higher risk nutrients leaching.

The availability of potassium (K), calcium (Ca) and magnesium (Mg) in the soil affects the nutrition and productivity of the plant cover. The Ca:Mg, Ca:K and Mg:K stoichiometric ratios indicate the nutrient load balance in the soil. However, limited attention has been paid to providing a scientific basis for how changes in land use, especially the cultivation of forage, impacts the availability and reserves of base cations in semi-arid regions, since, in these environments, fertiliser is not used. Therefore, the aim of this study was to quantify the concentrations of soil K, Ca and Mg in areas of preserved Caatinga (PC), and areas where buffel grass (BG) has been cultivated for 40 years and Leucaena grass (LE) for 11 years. Four 100 x 100 cm trenches were opened in each type of plant cover and collections were made in the 0-5, 5-10, 10-15 and 15-20 cm layers. The concentrations of K, Ca and Mg and their ratios were determined and compared using the Mann-Whitney test. The soil under buffel grass showed higher concentrations of K and Mg, and a lower concentration of Ca. Compared to PC, LE presented a lower Ca content in the 0-5 cm layer only. BG had the lowest values for the Ca:Mg and Ca:K stoichiometric ratios due to depletion of the Ca. Despite being soluble and easily leached, K remained in the soil under each type of cover, favoured by the semi-arid climate. Soil Ca, which is exported due to grazing of the produced biomass, should be replaced so as not to compromise the support capacity of seasonally dry tropical environments through the cultivation of forages.

The aim of this work is to define indices of soil chemical quality in intense agricultural activity area surrounding Sobradinho Lake, State of Bahia, Brazil, by means of multivariate statistical techniques. Based on the factor scores, it was determined soil chemical quality index for depths of 0-0.10, 0.10-0.20 and 0.20-0.40 m, respectively, classifying soils as good, fair and poor, according to the performance of its attributes. Then realized the Discriminative Analysis in order to validate the results obtained and, knowing the chemical soil attributes that influence and are associated with soil quality in agriculture of the region. In this way, among the main results could be observed that the attributes exchangeable sodium percentage (ESP) and organic matter (OM) stood out as indicators of soil quality. The ESP was the more important attribute in discrimination models in the depths of 0.00-0.10 and 0.10-0.20 m and OM in the 0.20-0.40 m layer. These variables are the main responsible for discrimination and classification of soil groups. In general, the chemical quality of soils is not considered ideal mainly due to the low contents OM and the extremely sandy texture, denoting environmental fragility.

Root-knot nematode (RKN) is a serious threat to crops worldwide due to the difficulty in controlling it and the limited eco-friendly alternatives to deal with the biotic stress it causes. In the present work, water-extractable fractions obtained from vermicompost (WSFv), vermicompost enriched with Trichoderma asperellum (WSFta) and T. virens (WSFtv) were tested as biotechnological tools to reduce the impacts of RKN on gas exchange, water use efficiency (WUE) and nutrient concentration in tomato and bell pepper plants. The plants were infected with 5000 eggs and eventual J2 of RKN and then treated with the water-extractable fractions for seven weeks. It was observed that the addition of WSFta, WSFtv and WSFv increased the CO2 assimilation, stomatal conductance and WUE in the tomato plants. In the bell pepper plants, WSFta, WSFtv, WSFv increased the stomatal conductance, while WUE was higher in the treatment with WSFtv. In fact, the parameters associated with the gas exchange were usually higher in the bell pepper than in the tomato plants. Overall, higher contents of N, Mg, B and Mn were detected when the extracts were applied in both bell pepper and tomato plants. The application of the water-extractable fractions, inoculated or not with Trichoderma, attenuates the RKN damage on the gas exchange parameters and successfully enhanced the nutrient concentration in the infected tomato and bell pepper plants, showing that it could be an important and promising tool for reducing the damage caused by this pathogen. We suggest that both the tomato and pepper plants can cope with the dilemma between growth and stress response via stomata regulation that are modulated by the WSF and Trichoderma.

Os sistemas de manejo podem influenciar atributos químicos do solo, sendo importante a busca de aplicação de novas técnicas para a compreensão dos efeitos ocasionados. Objetivou-se avaliar atributos químicos de um Latossolo Vermelho distroférrico sob sistemas de manejo por meio da estatística multivariada. Os tratamentos consistiram dos seguintes sistemas de manejo do solo: plantio direto, plantio direto escarificado, plantio direto escarificado cruzado, preparo convencional, preparo reduzido e preparo conservacionista. O trabalho foi conduzido com delineamento em blocos ao acaso com quatro repetições, sendo as amostras coletadas nas camadas de 0,00-0,10 e 0,10-0,20 m. Os atributos analisados foram: pH em água; matéria orgânica; cálcio, magnésio, potássio e alumínio trocáveis; fósforo e acidez potencial, com posterior cálculo da soma de bases, da capacidade de troca de cátions a pH 7,0 e da saturação por bases. Os dados foram analisados por meio de agrupamentos e componentes principais. Verificou-se que o sistema de preparo convencional e plantio direto na camada de 0,00-0,10 m apresentaram similaridade, e que preparo reduzido e plantio direto escarificado cruzado comparado aos demais sistemas, concentraram o maior número de atributos químicos e foram influenciados pelos valores de cálcio, magnésio, soma de base, capacidade de troca de cátions e saturação por base. Na camada de 0,10-0,20 m, os subgrupos plantio direto escarificado cruzado, preparo convencional, preparo reduzido e plantio direito concentraram grande parte dos atributos químicos, sendo influenciado pelos valores de potássio, soma de base, magnésio, capacidade de troca de cátions, saturação por base, matéria orgânica e pH.

ABSTRACT Knowledge of the decomposition dynamics of aboveground phytomass and its release of nutrients in mixtures of cover crops as well as the impact on the soil tillage system is fundamental for the sustainable management of agroecosystems. This work aimed to evaluate whether soil tillage and the choice of cover crops cultivated in the interrows can be technological strategies to increase dry biomass production, increase the capacity to add carbon, and improve macronutrient cycling in a mango ( Mangifera indica L.) orchard in a semi-arid environment. The field experiment (sixth year) consisted of two soil tillage systems (NT-no tillage and CT-conventional tillage) combined with three plant mixtures (PM1-75 % leguminous + 25 % grasses and oilseed species, PM2-25 % leguminous + 75 % grasses and oilseed species, and SV - spontaneous vegetation). Phytomass production and nutrient accumulation were not affected by the soil tillage system, but PM1 had the highest phytomass production and accumulations of C, N, and K, and it was significantly superior to SV. Regardless of the type of plant mixture, cultivated or spontaneous, soil tillage increased the rates of phytomass decomposition and nutrient release evaluated for 315 days after the cover plant management. The PM1 had the highest rates of decomposition and release of P and K, followed by PM2 and SV. There was no difference between the mixtures for the release of N, Ca, and Mg. The use of a mixture of cover crops, regardless of the predominance of leguminous or non-leguminous species, and a no-tillage system were technological strategies that could be adopted to favor the addition of soil carbon and nutrient cycling in fruit agroecosystems in the Brazilian semi-arid region. Spontaneous vegetation, due to its capacity to accumulate nutrients and the recalcitrant characteristics of its phytomass, has the potential to cycle nutrients and keep the soil covered. In addition, spontaneous vegetation should be better investigated because it is a low-cost strategy in agroecosystem designs.

Toxoplasma gondii is able to infect a wide range of vertebrates, including humans. Studies show that cyclooxygenase-2 (COX-2) is a modulator of immune response in multiple types of infection, such as Trypanosoma cruzi. However, the role of COX-2 during T. gondii infection is still unclear. The aim of this study was to investigate the role of COX-2 during infection by moderately or highly virulent strains of T. gondii in Calomys callosus rodents and human THP-1 cells. C. callosus were infected with 50 cysts of T. gondii (ME49), treated with COX-2 inhibitors (meloxicam or celecoxib) and evaluated to check body weight and morbidity. After 40 days, brain and serum were collected for detection of T. gondii by real-time PCR and immunohistochemistry or cytokines by CBA. Furthermore, peritoneal macrophages or THP-1 cells, infected with RH strain or uninfected, were treated with meloxicam or celecoxib to evaluate the parasite proliferation by colorimetric assay and cytokine production by ELISA. Finally, in order to verify the role of prostaglandin E2 in COX-2 mechanism, THP-1 cells were infected, treated with meloxicam or celecoxib plus PGE2, and analyzed to parasite proliferation and cytokine production. The data showed that body weight and morbidity of the animals changed after infection by T. gondii, under both treatments. Immunohistochemistry and real-time PCR showed a reduction of T. gondii in brains of animals treated with both COX-2 inhibitors. Additionally, it was observed that both COX-2 inhibitors controlled the T. gondii proliferation in peritoneal macrophages and THP-1 cells, and the treatment with PGE2 restored the parasite growth in THP-1 cells blocked to COX-2. In the serum of Calomys, upregulation of pro-inflammatory cytokines was detected, while the supernatants of peritoneal macrophages and THP-1 cells demonstrated significant production of TNF and nitrite, or TNF, nitrite and MIF, respectively, under both COX-2 inhibitors. Finally, PGE2 treatment in THP-1 cells triggered downmodulation of pro-inflammatory mediators and upregulation of IL-8 and IL-10. Thus, COX-2 is an immune mediator involved in the susceptibility to T. gondii regardless of strain or cell types, since inhibition of this enzyme induced control of infection by upregulating important pro-inflammatory mediators against Toxoplasma.

Zinc, copper, and manganese are prominent essential trace (or micro) minerals, being required in small, but adequate, amounts by pigs and poultry for normal biological functioning. Feed is a source of trace minerals for pigs and poultry but variable bioavailability in typical feed ingredients means that supplementation with low-cost oxides and sulphates has become common practice. Such trace mineral supplementation often provides significant ‘safety margins’, while copper and zinc have been supplemented at supra-nutritional (or pharmacological) levels to improve health and/or growth performance. Regulatory mechanisms ensure that much of this oversupply is excreted by the host into the environment, which can be toxic to plants and microorganisms or promote antimicrobial resistance in microbes, and thus supplying trace minerals more precisely to pigs and poultry is necessary. The gastrointestinal tract is thus central to the maintenance of trace mineral homeostasis and the provision of supra-nutritional or pharmacological levels is associated with modification of the gut environment, such as the microbiome. This review, therefore, considers recent advances in understanding the influence of zinc, copper, and manganese on the gastrointestinal environment of pigs and poultry, including more novel, alternative sources seeking to maintain supra-nutritional benefits with minimal environmental impact.

The aim of this study was to assess the organic matter changes in quantity and quality, particularly of the humic fraction in the surface layer (0–20 cm), of a Typic Plinthustalf soil under different management of plant mixtures used as green manure for mango (Mangifera indica L.) crops. The plant mixtures, which were seeded between rows of mango trees, were formed by two groups of leguminous and non-leguminous plants. Prior to sowing, seeds were combined in different proportions and compositions constituting the following treatments: 100% non-leguminous species (NL); 100% leguminous species (L); 75% L and 25% NL; 50% L and 50% NL; 25% L and 75% NL; and 100% spontaneous vegetation, considered a control. The plant mixtures that grew between rows of mango trees caused changes in the chemical composition of the soil organic matter, especially for the treatments 50% L and 50% NL and 25% L and 75% NL, which increased the content of humic substances in the soil organic matter. However, the treatment 25% L and 75% NL was best at minimising loss of total organic carbon from the soil. The humic acids studied have mostly aliphatic characteristics, showing large amounts of carboxylic and nitrogen groups and indicating that most of the organic carbon was formed by humic substances, with fulvic acid dominating among the alkali soluble fractions.

Changes in soils management systems, including the application of green manure, are able to increase crop productivity. The aim of this study was to propose a soil management system with the use of green manure to improve the nutritional status and melon productivity in the submedian of the São Francisco Valley. The experiment was installed in Typic Plinthustalf and conducted in split plot. There were two soil tillage systems, tillage (T) and no tillage (NT), and three types of green manure (two vegetal cocktails: VC1- 75% legumes (L) + 25% non-legumes (NL); VC2- 25% L+ 75% NL and spontaneous vegetation (SV)). The experimental design was a randomised block with four replications. Fourteen species of legumes, grasses and oilseeds were used for the composition of the plant cocktails. We evaluated production of the dry shoot and root biomass and carbon and nutrient accumulation by green manures and melon plant. Data were subjected to analysis of variance and the treatment means were compared by Tukey´s test (P

RESUMO A conversão de uma condição natural para uma de uso agrícola pode impor mudanças em atributos, propriedades e processos do solo e trazer consequências ambientais para a região de sua abrangência. O objetivo deste trabalho foi avaliar a qualidade física do solo em áreas agrícolas de municípios do entorno do lago de Sobradinho, região semiárida do Estado da Bahia, tendo como ferramenta técnicas estatísticas de análise multivariada. Inicialmente, aplicaram-se as análises estatísticas descritiva e de correlação e o teste de normalidade, que serviram como pressupostos para realizar análise fatorial e estimativa dos escores fatoriais. Com base nesses, determinou-se o índice de qualidade física de solo para as profundidades de 0,00-0,10; 0,10-0,20; e 0,20-0,40 m, respectivamente, cujo principal objetivo foi classificar os solos como bom, regular e ruim, de acordo com o desempenho dos seus atributos físicos. Em seguida, realizou-se a análise discriminante para validação dos índices construídos a partir dos resultados da análise fatorial, bem como conhecer os atributos físicos do solo que influenciam e estão associados à qualidade desse na área agrícola da região. A densidade do solo (Ds), macroporosidade (Ma) e microporosidade (Mi) foram os atributos que se destacaram como indicadores de qualidade, pois apresentaram maior peso relativo nos modelos de discriminação dos sítios amostrados: Ds, Ma e Mi, nas camadas de 0,00-0,10 e 0,10-0,20 m; e Mi e Ds, de 0,20-0,40 m, sugerindo que nas condições estudadas essas variáveis são as principais responsáveis pela qualidade física dos solos. No geral, a qualidade física do solo não foi considerada ideal, fato que pode ser atribuído às práticas de manejo adotadas e, sobretudo, aos baixos teores de matéria orgânica e à textura extremamente arenosa, conferindo fragilidade aos solos da região.

Soils under natural conditions have heavy metals in variable concentrations and there may be an increase in these elements as a result of the agricultural practices adopted. Transport of heavy metals in soil mainly occurs in forms dissolved in the soil solution or associated with solid particles, water being their main means of transport. In this context, the aim of this study was to evaluate the heavy metal and micronutrient content in the soil and in the grapevine plant and fruit under different irrigation strategies. The experiment was carried out in Petrolina, PE, Brazil. The treatments consisted of three irrigation strategies: full irrigation (FI), regulated deficit irrigation (RDI), and deficit irrigation (DI). During the period of grape maturation, soil samples were collected at the depths of 0-10, 10-20, 20-40, 40-60, and 60-80 cm. In addition, leaves were collected at the time of ripening of the bunches, and berries were collected at harvest. Thus, the heavy metal and micronutrient contents were determined in the soil, leaves, and berries. The heavy metal and micronutrient contents in the soil showed a stochastic pattern in relation to the different irrigation strategies. The different irrigation strategies did not affect the heavy metal and micronutrient contents in the vine leaves, and they were below the contents considered toxic to the plant. In contrast, the greater availability of water in the FI treatment favored a greater Cu content in the grape, which may be a risk to vines, causing instability and turbidity. Thus, adoption of deficit irrigation is recommended so as to avoid compromising the stability of tropical wines of the Brazilian Northeast.

Com o objetivo de avaliar o crescimento e o acúmulo de nutrientes por híbridos de melão desenvolveram-se experimentos em área comercial no município de Baraúna-RN, e na estação experimental de Bebedouro (Petrolina-PE) da Embrapa Semiárido. Em Baraúna-RN, o experimento foi desenvolvido de setembro a novembro de 2010, e em Petrolina-PE, de agosto a outubro de 2010. O delineamento experimental foi em blocos casualizados completos, com quatro repetições, em esquema fatorial 2 x 5. Os tratamentos resultaram da combinação de dois híbridos de melão (Iracema e Gran Prix) e cinco épocas de coletas de plantas (15; 25; 35; 45 e 55 dias após o transplante, DAT). Para se fazer um programa de adubação na cultura do meloeiro, tanto do grupo Amarelo como do grupo Pele-de-Sapo, observou-se um crescimento lento no início, maior incremento da parte aérea de 35 a 45 DAT e maior exigência da planta para o estádio de frutificação de 35 a 45 DAT para 'Iracema' e 45 a 55 DAT para 'Gran Prix' Quanto ao acúmulo, para os dois materiais e nos dois locais, observou-se a seguinte ordem: K>N>P>Ca>Mg.

A recuperação de áreas de floresta, principalmente de matas ciliares, tornou-se fator-chave para a adequação ambiental da agricultura, com o propósito de proteger os recursos hídricos e a biota. Entretanto, o cultivo agrícola tradicional, além de ter alterado a ciclagem de nutrientes com a perda de matéria orgânica, biomassa e atividade microbiana, causou também a compactação do solo, o que influencia a posterior implantação de reflorestamentos. O objetivo deste trabalho foi identificar quais atributos do solo (físicos, químicos e microbiológicos) mais influenciam o teor de C, N, P e umidade da serapilheira em áreas de mata ciliar com diferentes idades de recuperação (20, 10 e cinco anos), em comparação com uma área nativa (NT). A partir da ANOVA e dos testes de médias (Duncan) e correlação (Pearson), foram verificados quais atributos acompanham o tempo de recuperação e qual a relação entre eles. A análise multivariada de partição da inércia a partir da análise de redundância (pRDA) foi feita a fim de identificar quais atributos do solo foram mais importantes para discriminar entre as áreas, com base nos teores de C, N, P e umidade da serapilheira encontrados nessas áreas. Maior relação C/N da serapilheira foi encontrada nas áreas de 20 (26,8) e de cinco (29,9) anos. Entre os atributos microbiológicos avaliados, observou-se que a respiração basal do solo (C-CO2), o carbono da biomassa microbiana (CBM) e a atividade das enzimas desidrogenase e urease foram diretamente proporcionais ao aumento da idade das áreas. O C e N totais do solo, o N-NO3, o nitrogênio da biomassa microbiana (NBM), a atividade das enzimas desidrogenase e urease, bem como a macroporosidade correlacionaram-se positivamente e a microporosidade, negativamente, com o C e N da serapilheira. A partir da pRDA, o NBM e o carbono total do solo foram os atributos mais importantes para explicar o teor de N e C da serapilheira; a explicação compartilhada foi mais da metade de toda a explicação observada ou 28,2 %. A melhoria das condições físicas do solo e a adição de matéria orgânica que resultam na formação de uma serapilheira mais rica em N pode ser uma forma de melhorar as condições microbiológicas e químicas do solo e de acelerar o processo de recuperação.

Soil Health refers to the ecological equilibrium and the functionality of a soil and its capacity to maintain a well balanced ecosystem with high biodiversity above and below surface, and productivity. To understand and use soil health as a tool for sustainability, physical, chemical, and biological properties must be employed to verify which respond to the soil use and management within a desired timescale. Attributes with a rapid response to natural or anthropogenic actions are considered good indicators of soil health. Among the physical indicators, soil texture, aggregation, moisture, porosity, and bulk density have been used, while among chemical indicators total C and N, mineral nutrients, organic matter, cation exchange capacity, among others are well established. However, most of them generally have a slow response, when compared to the biological ones, such as microbial biomass C and N, biodiversity, soil enzymes, soil respiration, etc., in addition to macro and mesofauna. Thus, a systemic approach based on different kinds of indicators (physical, chemical and biological) in assessing soil health would be safer than using only one kind of attribute. Many human activities have caused desertification, loss of biodiversity, disruption of aggregates, loss of organic matter and nutrients, among others. Today, it is imperious to maintain soil health and productivity with increasing emphasis on reforestation and recuperation of degraded areas through the use of organic amendments, reintroduction of plants, soil fauna and microorganisms. This review focused on an integrative view on indicators of soil health to be used as tools for prediction of sustainability in production systems.

A decomposição e liberação de nutrientes de resíduos vegetais podem assumir importante papel no manejo da fertilidade dos solos da região semiárida. Portanto, o presente estudo teve por objetivo avaliar a taxa de decomposição da matéria seca (MS) e liberação de carbono (C) e nutrientes de coquetéis vegetais no Semiárido brasileiro. O experimento foi conduzido em casa de vegetação, no período de novembro de 2007 a junho de 2008, com coquetéis vegetais compostos por espécies de leguminosas (L) (calopogônio, Crotalaria juncea, Crotalaria spectabilis, feijão de porco, guandu, lab-lab) e não leguminosas (NL) (gergelim, girassol, mamona, milheto e sorgo), combinados nos seguintes tratamentos: T1 - 100% NL; T2 - 100% L; T3 - 75% L e 25% NL; T 4 - 50% L e 50% NL; T5 - 25% L e 75% NL. As taxas de decomposição da MS e liberação dos nutrientes foram monitoradas por meio de coleta dos resíduos, realizadas aos 8; 15; 30; 60; 90; 120; 150; 180 e 210 dias após o início do experimento. Utilizou-se o delineamento experimental em blocos casualizados com três repetições. Os coquetéis apresentaram taxas de decomposição de MS e liberação de nutrientes semelhantes, exceto para Ca, Cu e Mn, em que os coquetéis compostos com predominância de espécies NL apresentaram liberação mais rápida. A partir da média dos valores de k para todos os coquetéis estabeleceu-se a seguinte ordem de liberação de macronutrientes: K > N > Ca > Mg > P e de micronutrientes: Fe > Mn > Cu > Zn > B.The decomposition and release of nutrients from plant residues can play an important role in the maintenance of soil fertility in semi-arid regions. Thus this study aimed to evaluate the rate of decomposition of dry matter (DM) and the release of carbon (C) and nutrients from plant mixtures used as green manure in the Brazilian Semi-arid regions. The experiment was carried out in a greenhouse, from November 2007 to July 2008, using plant mixtures made up of leguminous species (L) (calopo, Crotalaria juncea, Crotalaria spectabilis, jackbean, pigeon pea, lab-lab) and non-leguminous species (NL) (sesame, sunflower, castor, millet and sorghum) combined to give the following treatments: T1 - 100% NL, T2 - 100% L, T3 - 75% L and 25% NL, T4 - 50% L and 50% NL, T5 - 25% L and 75% NL. The rates of decomposition and the release of nutrients were monitored through collection of the residue at 8; 15; 30; 60; 90; 120; 150; 180 and 210 days after the beginning of the experiment. A randomized-block design was used, with three replications. The mixtures showed similar decomposition rates of DM and nutrient release, except for Ca, Cu and Mn, where the mixtures composed predominantly of NL species showed a higher release rate./ From the average values of k for all of the mixtures, it was possible to establish the following order of release of macronutrients: K> N> Ca> Mg> P and micronutrients: Fe> Mn> Cu> Zn> B.

This study investigated the microbial metabolism in Bermuda-grass Tifton 85 areas after potable-water and effluent irrigation treatments. The experiment was carried out in Lins/SP with samples taken in the rainy and dry seasons (2006) after one year and three years of irrigation management, and set up on an entirely randomized block design with four treatments: C (control, without irrigation or fertilization), PW (potable water + 520 kg of N ha-1 year-1); TE3 and TE0 (treated effluent + 520 kg of N ha-1 year-1) for three years and one year, respectively. The parameters determined were: microbial biomass carbon, microbial activity, and metabolic quotient. Irrigation with wastewater after three years indicated no alteration in soil quality for C and ET3; for PW, a negative impact on soil quality (microbial biomass decrease) suggested that water-potable irrigation in Lins is not an adequate option. Microbial activity alterations observed in TE0 characterize a priming effect.

ResumoA salinidade do solo constitui um sério problema nas áreas irrigadas, principalmente quando sua intensidade interfere no desenvolvimento das culturas, reduzindo a produção e a produtividade das plantas, a níveis antieconômicos. Este problema é mais frequente em regiões tropicais de clima quente e seco, caracterizado por elevadas taxas de evapotranspiração e baixos índices pluviométricos, a exemplo do semiárido do Nordeste brasileiro. O objetivo do presente estudo foi a aplicação de análise estatística multivariada na discriminação de diferentes classes de solos irrigados com águas salinas, na região de Mossoró (RN). O delineamento experimental foi o de blocos ao acaso, em esquema fatorial 4 x 8 x 2, constituído pela combinação de quatro solos (Latossolo, Cambissolo, Argissolo e Neossolo Flúvico), oito valores de CE (100, 250, 500, 750, 1.250, 1.750, 2.250 e 3.000 μS cm-1) e dois de RAS (4 e 12), com três repetições. Avaliou-se a ação conjunta dos atributos químicos como os cátions trocáveis e os cátions e ânions solúveis, na discriminação dos solos, efetuaram-se análises estatísticas multivariadas de agrupamentos e de componentes principais. A estratégia de agrupamento utilizada foi ligação simples (single linkage), que possibilitou obter agrupamentos sequenciais, aglomerativos, hierárquicos e não superpostos expressando os resultados através de gráficos de esquemas hierárquicos ou dendogramas. A análise estatística multivariada classificou os solos em três grupos de acordo com a similaridade de seus atributos químicos, independente de sua classificação taxonômica. AbstractSoil salinity is a serious problem in irrigated areas, especially when it interferes with plant growth, reducing yield to uneconomic levels. This problem is more common in hot and dry tropical regions, characterized by high evapotranspiration and low precipitation levels, as for example the Brazilian Northeast Semi-Arid. This work aims the application of multivariate statistical analysis for the discrimination of different soil classes irrigated with saline water in Mossoró - RN region. The experimental design was a randomized block, in a factorial arrangement 4 x 8 x 2, formed by four soils (Oxisols, Inceptisol, Ultisol e Typic Haplaquents), eight electrical conductivity levels (100, 250, 500, 750, 1.250, 1.750, 2.250 and 3.000 μS cm-1) and two sodium adsorption rates (4 and 12), with three replicates. The joint action of chemical attributes such as exchangeable cations, and soluble cations and anions on soil discrimination was evaluated by multivariate techniques of clustering and principal component analysis. The clustering strategy used was single linkage, which allowed sequential clusters, agglomerative, hierarchical and non-superimposed, expressing the results through hierarchical schemes graphs or dendograms. Multivariate statistical analysis (clustering and principal component analysis) classified the soils into three soil groups according to the similarity of their chemical attributes, independently of their taxonomical classification.

Objetivou-se avaliar o efeito do composto de lixo urbano nos parâmetros morfológicos de mudas de sesbânia e de angico. Os substratos de cultivo tiveram as seguintes proporções de composto e de amostras de subsolo de Neossolo Quartzarênico ou de Latossolo Vermelho-Amarelo (%): 0:100; 20:80; 40:60; 60:40 e 80:20, sem a utilização de fertilização mineral. As sementes de sesbânia foram inoculadas com a estirpe recomendada BR 5401. Os parâmetros morfológicos das mudas de sesbânia e angico, suas relações e índice de qualidade de Dickson (IQD) foram determinados aos 56 e 120 dias após a semeadura, respectivamente para cada espécie. Os efeitos dos substratos nos parâmetros morfológicos das mudas de sesbânia e angico variaram de acordo com as proporções do substrato. Para o angico, a adição do composto proporcionou aumento na altura da parte aérea, razão entre massa seca de parte aérea por massa seca de raiz e IQD. Para sesbânia, a adição do composto de lixo ao substrato proporcionou aumento na altura da parte aérea, diâmetro do coleto, massa seca de raiz, da parte aérea e total, razão entre massa seca da parte aérea por massa seca de raiz, IQD e número de nódulos. A obtenção de máxima produção de matéria seca total, diâmetro do coleto e IQD foi de 57:43, sendo, portanto, esta a proporção composta de lixo:solo recomendada para a produção de mudas de sesbânia.This work aimed to evaluate the effect of urban waste compost on morphological parameters of "sesbânia" and "angico" seedlings. The substrates had the following proportion of compost and subsoil samples of Quartz-Sand Neosol or Red-Yellow Latosol (%): 0:100; 20:80; 40:60; 60:40 and 80:20, without mineral fertilizer. Seeds of Sesbania virgata were inoculated with the recommended strain BR 5401. Morphological parameters of seedlings, their relationships and the Dickson Index of Quality (IQD) were determined to "sesbânia" and "angico" at 56 and 120 days after sowing respectively. The substrate effect on morphological parameters of "sesbânia" and "angico" seedlings varied according to substrate proportion. Compost addition caused increase in height, shoot and root dry matter weight ratio and IQD of "angico", therefore not being recommend any one of the substrate proportions to this species. As for "sesbânia", shoot, root and total dry matter weight, stem diameter, shoot area, shoot and root dry matter weight ratio, IQD and number of nodules were directly related to the addition of waste compost to the substrate. Maximum production of total dry matter weight, stem diameter and IQD were obtained with the proportion 57:43. Thus, we recommend this e proportion of waste compost and soil for the production of "sesbânia" seedlings.

Com o objetivo de avaliar o efeito da aplicação pré-colheita de cálcio na qualidade e no teor de nutrientes de frutos de manga Tommy Atkins, foi realizado um experimento em um pomar comercial com dez anos de idade, localizado no município de Petrolina-PE. Foram avaliados sete tratamentos, sendo duas fontes comerciais de cálcio e três dosagens de cada fonte (5,8; 11,6 e 17,4 mmol L-1 de Ca na forma de Ca-quelatizado e 45,0; 90,0 e 135,0 mmol L-1 de Ca na forma de CaCl2.2H2O), além de um tratamento-controle. O delineamento experimental foi em blocos ao acaso, com quatro repetições. As aplicações dos tratamentos foram realizadas quinzenalmente, iniciadas quando os frutos apresentavam tamanho chumbinho (5 a 10 mm) e estenderam-se até duas semanas antes da colheita. Foram realizadas seis pulverizações de uma calda contendo os tratamentos, sendo que, em cada aplicação, foram fornecidos 12,5 L/planta de calda. Os frutos foram colhidos no estádio de maturação 2. Quarenta frutos, agrupados em lotes de dez, foram acondicionados em caixas de papelão com capacidade para 6 kg e submetidos ao armazenamento por 0; 20; 30 e 40 dias sob refrigeração (10.5±1.0°C e 90±5% de UR). Depois de retirados da câmara fria, os frutos foram mantidos por cinco dias em sala de amadurecimento a 21±1°C e 60±5% de UR. Foram determinados os teores de N, K, Ca e Mg na casca e na polpa dos frutos no lote equivalente ao tempo inicial de armazenamento e avaliada a incidência de colapso interno em todos os lotes. A aplicação de cálcio tanto na forma quelatizada quanto de sal solúvel aumentou as concentrações do nutriente na casca dos frutos. Aplicações de Ca-quelatizado mostraram-se eficientes em aumentar as concentrações de cálcio na polpa dos frutos, podendo contribuir para prevenir a ocorrência de colapso interno em curto período de armazenamento.The effect of calcium on quality and nutrient level of mango cv. "Tommy Atkins" was studied when applied prior to harvest on a ten-year old orchard, in Petrolina, State of Pernambuco, Brazil. Three levels of two commercial calcium sources (5.8; 11.6 and 17.3 mmol L-1 of Ca as chelate Ca and 45.0; 90.0 and 135.0 mmol L-1 of Ca as the soluble salt CaCl2.2H2O), and a control treatment were evaluated, in a randomized complete block design with four replications. Calcium was applied every two weeks, starting at the fruit set stage (fruits 5 to 10 mm long) up to two weeks before harvest. Six sprayings of solutions containing the calcium treatments were applied providing 12.5 L of the solution/plant in each application. The fruits were harvested in the ripening stage 2. Forty fruits were grouped in four lots of ten, placed into cardboard boxes with capacity for 6 kg and stored for 0, 20, 30 and 40 days under refrigeration (10.5±1.0°C and 90±5% RH). After removed from the cold chamber, the fruits were kept for five days in a ripening room at 21±1°C and 60±5% RH. N, K, Ca and Mg contents in the flesh and skin were determined in the lot equivalent to the shortest time of storage and the incidence of internal breakdown was evaluated in all four lots. Calcium application in both chelate and soluble salt forms increased the nutrient contents in the skin. Applications of chelate Ca showed to be efficient in increasing the calcium contents in the fruit flesh, contributing to prevent the occurrence of internal breakdown in short storage periods.

This work had as objective studying the extraction of cadmium and evaluate four extractors as conventional chemical: Mehlich-1, Mehlich-3, TEA-DTPA and CaCl2 as indicators of the availability of cadmium in plants (Zea mays) in soils of the state of Rio Grande do Norte. The soils were submitted to the correction of pH and chemical and physical analysis. The determination of total cadmium in samples of soil, were made through the technique of digestion digesters in tubes containing nitric acid with the ratio of 3:1 v / v (aqua regia). The extracts were read by the atomic absorption spectrometry, setting up the total concentration of cadmium in the samples. For the extraction of cadmium in the plant samples were submitted to digestion nitric-perclórica will ratio of 3:1 (v / v). Statistical analyses were made in the programme Statistic 6.0, where the data were submitted to the analysis of variance and correlation, is adopting levels of significance of 1% and 5% probability. The capacidae recovery of extractors used followed the following order: Water Régia> Mehlich-1> Mehlich-3> DTPA-TEA> CaCl2. The aqua regia was a good extractor for phytoavailability, presenting the second highest correlation coefficient. The CaCl2 was given the best extractor due to the availability has presented better correlation between the cadmium content in dry plant maize and extracted by extratoras tested solutions. On average the Neossolo Quartzarênico led to better absorption of cadmium by plants of maize and Neossolo Flúvico and Haplic Cambisol the minors.

For proposition of the better recovery practice is necessary to identify the main characteristics of index fingers soil of environmental degradation. For so much, it should seize upon chemical, physical and biological analyses. Thus, the goal of this work was to study some chemical indicators of environmental degradation in soils terms of semiarid. The soils were collected in the pilot's area JICA Project located in the municipal district of Pedro Avelino-RN, the choice of the area was due to your desertification degree. The analyses were accomplished in Soil, Plant and Water Analyses Laboratory of the University Semi-arid Rural Federal. The samples were collected in the layers of 5, 10, 20, 30 and 50 cm. The accomplished chemical analyses were: pH in water (1:2,5); Electric Conductivity (CE) in the extract 1:5; Ca+2,Mg+2, Na+ and K+ exchangeable, and P available. By the results, it verified that pH and CE increased with the depth, with regard to the contents of In the Na+ in the soil there was variation with the increase of the depth. To the thwart of the majority of the analyzed elements the K+ tended to decrease your content in the soil with the increase of the depth, The sodium elevated contents should be carried in consideration for the implantation of the recovery project, using itself preferentially resistant plants of sodicity.

A contaminação do solo por compostos orgânicos, especialmente os hidrocarbonetos aromáticos policíclicos (HAPs) de petróleo, é um problema crescente e que traz graves conseqüências ambientais. Para avaliar os impactos causados por esses compostos, torna-se necessário conhecer seus efeitos sobre as plantas e a microbiota rizosférica associada. No presente estudo avaliaram-se os efeitos de antraceno e creosoto no crescimento e na colonização micorrízica de Brachiaria brizantha e Pueraria phaseoloides. Antraceno e creosoto foram aplicados a um solo infestado com o fungo micorrízico Glomus etunicatum, sendo: antraceno nas concentrações de 0; 0,25; 0,5; 0,75 e 1 g kg-1 solo; e creosoto nas concentrações de 0; 0,5; 1; 2 e 3 g kg-1 solo. O solo com os tratamentos foi colocado em tubetes (290 cm³) e semeado com as plantas-teste, as quais foram cultivadas por seis semanas. Verificou-se que o antraceno não afetou o crescimento da puerária e teve pequeno estímulo no crescimento da braquiária na dose mais baixa, enquanto o creosoto reduziu o crescimento da braquiária e não teve efeito na puerária. Entretanto, ambos os contaminantes inibiram a colonização micorrízica da puerária, atingindo redução de cerca de 90 % em relação ao controle. Em concentrações bem inferiores às encontradas em solos contaminados, a colonização micorrízica foi inibida em 50 %, ficando evidente o potencial de impacto desses poluentes na relação planta-fungo micorrízico. Na braquiária não foi encontrada colonização micorrízica. Fica evidenciada a resposta diferenciada das duas espécies estudadas aos contaminantes e o acentuado efeito negativo destes sobre a colonização micorrízica. A puerária, por ter se mostrado insensível aos HAPs, nas concentrações estudadas, apresenta potencial para aplicação na fitorremediação de áreas impactadas por esses contaminantes.Soil contamination by organic compounds, especially by the petroleum-derived, polycyclic aromatic hydrocarbons (PAHs), is a growing problem with serious environmental consequences. To evaluate the environmental impact of these products it is important to understand their effects on plants and the associated microbiota. The effects of PAHs on growth and mycorrhizal colonization of Brachiaria brizantha and Pueraria phaseoloides were evaluated here. Two PAHs, anthracene and creosote, were applied to a soil infested with the mycorrhizal fungus Glomus etunicatum at varied concentrations: anthracene (0; 0.25; 0.5; 0.75 and 1 g kg-1 soil) and creosote (0; 0.5; 1; 2 and 3 g kg-1 soil). This soil was packed into plastic tubes (290 cm³) where test plants were sown and grown for six weeks. It was found that anthracene did not affect pueraria growth and had a slight stimulus on brachiaria growth at the lowest concentration, whereas creosote had no effect on pueraria either, but inhibited brachiaria growth. Both contaminants inhibited mycorrhizal colonization in pueraria by about 90 %, compared to the control. At concentrations below those found in contaminated soils, AM colonization was inhibited by 50 %. The potential impact of these products on plant-AM fungus relationships is quite evident here. No colonization was found in brachiaria, regardless of the presence of PAHs. The results showed a differentiated sensitivity of the plants to the contaminants and their marked negative effect on G. etunicatum root colonization. In the evaluated concentration range, pueraria was insensitive to both compounds, which indicates the species for further studies on phytoremediation of areas under the impact of these contaminants.

Objetivou-se avaliar o uso do biossólido como componente do substrato para crescimento inicial de mudas de aroeira. Os substratos foram compostos de amostras de Neossolo Quartzarênico e de Latossolo Vermelho-Amarelo coletadas na profundidade de 0,2 a 0,5 m, acrescidos do biossólido produzido pela Estação de Tratamento de Esgoto (ETE) de Serrania, MG, nas seguintes proporções de solo:biossólido (%): 100:0; 80:20; 60:40; 40:60; e 20:80, sem a utilização de fertilização mineral. Após 30 dias da semeadura, foi feito o desbaste deixando-se uma planta por tubete, e, no final do período de 60 dias, as mudas foram coletadas para a determinação da massa seca da parte aérea (MSPA), das raízes (MSR) e total (MST), diâmetro de colo (D), altura das plantas (H), área foliar (A), relação altura da parte aérea com diâmetro do colo (H/D) e peso da massa seca da parte aérea com peso da massa seca da raiz (MSPA/MSR). O biossólido melhorou a fertilidade dos substratos, aumentando os teores de P, K, Ca, Mg, soma de bases, CTC, matéria orgânica e teores de micronutrientes, fato que proporcionou aumento no D, A, MSPA, MSR, MST, H, MSPA/MSR das mudas de aroeira, sendo que esses efeitos variaram de acordo com as proporções de biossólido empregadas. O crescimento máximo das mudas foi obtido com a proporção de 63:37, tanto para Neossolo Quartzarênico quanto Latossolo Vermelho-Amarelo. A concentração de metais pesados em todos os substratos ficou abaixo dos limites estabelecidos pela CETESB.This work aimed to evaluate sewage sludge as substrate component for aroeira seedling growth. Substrates were composed of soil samples collected at 0.2-0.5 m depth from a Quartzarenic Neosol or from a Red-Yellow Latosol, with sewage sludge produced by the Sewage Treatment Station (Estação de Tratamento de Esgoto - ETE) located in Serrania, Minas Gerais, in five proportions: 100:0; 80:20; 60:40; 40:60 and 20:80, being all without mineral fertilizers. Thirty days after sowing, thinning was carried out to one plant per pot. Aroeira growth after 60 days was evaluated by shoot and root dry weight, total dry matter, stem diameter, plant height, leaf area, shoot height/stem and diameter shoot/root ratio. Amendments with sewage sludge increased substrate fertility as indicated by P, K, Ca, Mg concentrations, CEC and SB values, organic matter and micronutrient contents, which promoted growth of stem diameter, plant height, shoot and root dry weight, total dry matter, leaf area, and shoot/root ratio in aroeira seedlings . The effect of sewage sludge on aroeira seedlings growth varied according to the different proportions of sewage sludge. Maximum growth was obtained with the proportion 37% of sewage sludge + 63% of Quartzarenic Neosol or Red-Yellow Latosol. Heavy metal concentration in all substrates was below the limits allowed by CETESB.

In many studies worldwide the use of treated sewage effluents (TSE) as water and nutrient sources in agricultural irrigation have been introduced as a viable alternative for wastewater destination in the environment. Considering agronomic and environmental aspects the objectives of this review were: (i) to present an overview of TSE irrigation on different agro-systems (annual crops, orchards, forests and forages); and (ii) to show the principal changes on chemical, physical and microbiological soil characteristics after TSE application. Various studies have revealed that the nutrient supply only by TSE irrigation was not sufficient to meet plant nutrient requirements resulting in yield decreases. The problem could be solved by an adapted effluent/fertilizer management. Moreover, TSE could generally substitute efficiently freshwater for irrigation. Regarding soil quality conditions, TSE irrigation affected mainly: (i) total soil carbon and nitrogen, and mineral nitrogen in soil solution; (ii) microbial activity, composition of microbial communities and their function; (iii) exchangeable calcium and magnesium; (iv) salinity, sodicity, clay dispersion and hydraulic conductivity. Other soil parameters considered in this review (e.g. heavy metals) did not present significant changes over short and medium terms. Due to the often observed accumulation of sodium and nitrogen losses (leaching, volatilization and denitrification) after TSE irrigation, the monitoring of these components is of crucial importance for a sustainable use. Finally, further studies on the technical-economical-environmental viability of TSE irrigation are required to establish reliable recommendations for TSE use particularly in Brazilian agro-systems.O uso dos efluentes de tratamento de esgoto (ETEs) como fonte d'água e nutrientes na agricultura (via irrigação) tem sido, em diversos locais, uma alternativa viável para a disposição das águas residuárias no ambiente. Os objetivos dessa revisão foram: (i) enfocar aspectos agronômicos e ambientais concernentes ao uso de ETEs em diferentes agrossistemas (culturas anuais, fruticultura, florestas e forragens); (ii) enfatizar as principais mudanças nas características químicas, físicas e microbiológicas dos solos irrigados com ETEs. Foram observados que, em diversos trabalhos, a irrigação com ETEs não foi suficiente para atender a demanda nutricional das plantas, resultando em diminuição no rendimento. Esse problema poderia ser resolvido mediante adequação do manejo da fertilização e irrigação. Além disso, os ETEs poderiam substituir eficientemente a água doce normalmente empregada na irrigação. Quanto a qualidade de solo, a irrigação com ETEs tem alterado principalmente os parâmetros: (i) carbono total e nitrogênio total no solo e nitrogênio mineral na solução no solo; (ii) atividade, composição e função da comunidade microbiana; (iii) cálcio e magnésio trocáveis; (iv) salinidade, sodicidade, dispersão de argilas e condutividade hidráulica. Outros parâmetros de qualidade de solo (por exemplo, metais pesados) não apresentaram mudanças significativas em curto e médio prazo. O monitoramento da acumulação de sódio e das perdas de nitrogênio (lixiviação, volatilização e denitrificação) é crucial para o uso sustentável dos ETEs na irrigação. Finalmente, mais estudos são necessários para mostrar a viabilidade técnico-econômico-ambiental, objetivando-se a recomendação segura dos ETEs na irrigação dos agrossistemas brasileiros.

Phosphorus fertilizers are essential to obtain high productivity, however, they contain heavy metals that can contaminate the soil and threat the health of animals and humans. The present study focused the determination of Cd and Pb concentrations in different phosphorus fertilizers as well as the absorption of these heavy metals by velvet green bean grown on soil amended with such fertilizers. The experiment was set up as a completely randomized design in a factorial scheme. The factors were four phosphorus sources (triple superphosphate-TS, Yorin thermophosphate-YT, Araxa rock phosphate-AP, and Gafsa rock phosphate-GP) applied at five rates (0, 92, 183, 275, and 366 kg ha-1 of P2O5). The data obtained were submitted to variance and regression analysis. Lead availability to velvet bean was not altered as a result of fertilizer application. On the other hand, Cd uptake was significantly increased with addition of the tested fertilizers. Such an increase was a function of the rate. The highest Cd contents in shoots was reached by YT and TS applications, whereas the lowest one resulted from rock phosphate treatments. All the phosphorus sources tested increased Cd uptake in the first harvest. For the second harvest, Cd content in the shoot was detected only in plants grown on TS and GP amended soils.Fertilizantes fosfatados são essenciais para obtenção de altas produtividades, entretanto, eles podem conter metais pesados que podem contaminar o solo e ameaçar a saúde humana e animal. Este trabalho objetivou a determinação da concentração de Cd e Pb em diferentes fertilizantes fosfatados, bem como a absorção desses metais por plantas de mucuna preta cultivadas em casa-de-vegetação em solo submetido a diferentes doses desses fertilizantes. Os tratamentos foram arranjados em esquema fatorial 4 x 5, dispostos em delineamento experimental inteiramente casualizado, com três repetições, sendo os fatores quatro fontes de P (superfosfato triplo-ST, termofosfato de Yorin-TY, fosfato de Araxá-FA e fosfato de Gafsa-FG) e cinco doses de P2O5 (0, 92, 183, 275 e 366 kg ha-1). Os dados foram submetidos à análise de variância e equações de regressão foram ajustadas. A disponibilidade de Pb para mucuna preta nos solos não foi alterada pela aplicação de nenhum dos fertilizantes testados. No entanto, a absorção de Cd pelas plantas foi significativamente aumentada pela aplicação de qualquer um dos fertilizantes, sendo esta absorção proporcional às doses aplicadas. O TY e o ST foram responsáveis pelas maiores concentrações de Cd na parte aérea das plantas, enquanto as menores foram observadas com a aplicação dos fosfatos naturais. Todas as fontes de fósforo disponibilizaram Cd para as plantas no primeiro cultivo. Entretanto, a absorção de Cd só foi detectada no segundo cultivo para os fertilizantes ST e FG.

Com o objetivo de avaliar a qualidade pós-colheita dos melões exportados pelo Porto de Natal-RN, identificando características qualitativas desfavoráveis que dificultem a exportação do melão, foram analisados 2.303 frutos no período de setembro a dezembro de 2002 com amostragem segundo as normas de fiscalização da Delegacia da Agricultura e do Abastecimento- DFA/SSV. O trabalho foi desenvolvido no Porto de Natal, na unidade do Vigiagro/SSV/MA. A avaliação dos frutos foi feita de maneira sistemática, seguindo o preenchimento de uma "Ficha de Controle de Qualidade do Melão Exportado" em que foram determinados o teor de sólidos solúveis totais e a firmeza de polpa. 50,33 % dos frutos analisados foram do tipo Amarelo, 19,06 % do tipo Orange Flesh, 9,90 % do tipo Pele de Sapo, 11,16 % do tipo Gália, 7,03 % do tipo Cantaloupe e 2,52% do tipo Charentais. Apenas os melões tipo Amarelo apresentaram teor médio de sólidos solúveis totais aceitáveis para a exportação; os melões tipo Pele de Sapo foram os que apresentaram menos firmeza de polpa.

This work had as objective to evaluate spatial variability of physical characteristics of a Typical Haplocambids (CX), under papaya culture, by means of the geostatistic. The analyzed area presented 43 sampling points , where soil samples were collected, in the layer of 0 ¿ 0.2 m. In the soil samples granulometry, soil bulk density, particles density, water content at tension of 0.03 and 1.5 MPa were measured. From these analyses the total porosity and water availability were calculated. Data were evaluated by descriptive statistics and by analysis of the spatial dependence based in semivariograms adjustment. The variation coefficient indicated low variability for total and coarse sand contents, water content at tension of 0.03 and 1.5 MPa, soil bulk and particles density and total porosity; and medium for clay, silt e available water contents. Except for water content at tension of 0.03 and 1.5 MPa and particles density, the other variables presented space dependence, being the spherical and exponential models adjusted to all the semivariograms. The nugget effect had small contribution in the data total variance, indicating strong spatial dependence for fine sand and clay contents, total porosity and available water. The other variables showed moderate dependence. There was a great variation in the distance until where the physical characteristics of the ground present spatial dependence (reach).