Preparo do solo e perda de nutrientes por erosão na cultura do pepino

Minimum tillage reportedly reduce erosion, avoid soil degradation and improve crop productivity. This study aimed to determine how tillage operations may affect either nutrient accumulation or nutrient losses by erosion. The study was, carried out from December, 2000 to March, 2001, in the watershed of the Caetés River, in Rio de Janeiro State, Brazil (22º25'43"S, 43º25'07"W). The experiment was set up in sandy clay Kandiudult soil, 60% slope, under cucumber (Cucumis sativus L.) crop. Soil samples were collected before planting and after harvest, on 22.0 X 4.0 m Greeoff plots. After each rainfall, fine sediments carried by runoff were deposited into two collecting tanks in a row, installed at the end of each plot, and were later dried, weighed and stored for analyses. Treatments (n = 4) were characterized by different tillage systems: (i) downhill plowing followed by the burning of crop residues (DPB); (ii) downhill plowing with no burning of the crop residues (DPNB); (iii) animal traction contour plowing, with strips of guinea grass planted at a spacing of 7.0 m (AT); and (iv) minimum tillage (MT). Samples of the soil-plowed layer were collected before planting and after harvest, between the rows and from the plants. Total concentration of Ca, Mg, K and P were determined after extraction with nitric perchloride digestion. Labile P and exchangeable K were extracted with the Mehlich 1 extractant solution. The MT system reduced losses of both exchangeable bases (15%) and P (8%), and affected the distribution of labile and organic P. Crop residues left on soil surface in the MT system, resulted in increased organic matter content. Downhill plowing, the most used tillage operation in the region, resulted in the greatest losses of Ca, Mg, K, and P.O cultivo mínimo reputadamente reduz a erosão, evita a degradação do solo e melhora a produtividade das culturas. Este trabalho teve por objetivo determinar a influência de diferentes métodos de preparo do solo sobre o acúmulo e perdas por erosão de nutrientes. O experimento foi realizado na microbacia de Caetés, município de Paty do Alferes RJ, (22º25'43"S, 43º25'07"O) durante os meses de dezembro de 2000 a março de 2001 no ciclo de cultivo do pepino (Cucumis sativus L.). O experimento foi localizado em Argissolo Vermelho Amarelo, intermediário latossólico textura argila arenosa/argilosa e declividade de 60%. Foram instaladas parcelas do tipo Wischmeier, numa área de 22,0 X 4,0 m com diferentes sistemas de preparo de solo. Ao final de cada parcela foram instalados dois tanques para o armazenamento das águas pluviais e dos sedimentos carreados pela enxurrada. Os tratamentos (n = 4) utilizados foram: (i) aração com trator morro abaixo e queima dos restos vegetais (MAQ); (ii) aração com trator morro abaixo não queimado com restos de vegetação natural entre as linhas (MANQ); (iii) aração com tração animal em nível, faixas de capim colonião a cada 7,0 m (AA) e (iv) cultivo mínimo (CM). Nas linhas e nas covas de cada parcela foram coletadas amostras da camada arável do solo antes do plantio e depois da colheita. Após cada chuva os sedimentos carreados pela erosão foram recolhidos, secos, pesados e guardados para posterior análise. As concentrações totais de Ca, Mg, K e P em solo e sedimentos foram determinadas em extratos nitro perclóricos. O CM reduziu as perdas das bases trocáveis e do P e também influenciou na distribuição nas formas lábil e orgânica de P. O aproveitamento dos resíduos vegetais, na parcela sob CM, propiciou aumento no teor de matéria orgânica. O tratamento MAQ, típico da região, foi o que apresentou as perdas mais elevadas de Ca, Mg, K e P

Valores de referência de alguns elementos-traço em solos intemperizados da região Norte brasileira

Solos formados a partir de sedimentos do Grupo Barreiras apresentam, em geral, baixos teores de ferro, mineralogia caulinítica, elevadas quantidades de quartzo na fração areia e pequena quantidade de carbono orgânico. Determinaram-se os teores de Cd, Co, Cr, Ni e Zn extraídos com água régia, em bloco digestor, em Argissolos Amarelos e Latossolos Amarelos sob vegetação natural do Pará e Amapá. Regressão linear múltipla foi utilizada para correlacionar os parâmetros de solo e os teores desses metais. Melhores correlações foram obtidas entre Fe, Mn, argila, silte e Cd, Co, Cu, Zn, Cr, Ni. Não foi encontrada correlação entre o pH e os teores de metais. Argila e areia apresentaram correlação inversa com os metais, porém de mesma magnitude, sendo necessária a exclusão de uma delas no modelo de regressão. Em geral, os teores dos elementos estudados foram inferiores aos encontrados em solos formados a partir de outros materiais de origem. O Mn foi incluído no modelo de regressão linear múltipla do Cd e Co, em função de sua associação com esses metais. O silte foi significativo nas equações para Cr e Co, o que pode ser devido à presença de minerais de argila e óxidos de Fe e Mn em agregados ferruginosos e argilosos de tamanho silte. Estas equações podem ser úteis quando se deseja conhecer, em termos gerais, quais as quantidades que determinada amostra teria se o solo em questão não estivesse contaminado ou sujeito a uso antrópico, podendo ser utilizadas na avaliação da contaminação do solo por estes metais.Soils formed from the Barreiras Group sediments, located mainly along the coast of Brazil Northern and Northeastern regions, generally present low concentrations of iron oxides and total organic carbon, high quantities of quartz in the sand fraction, and kaolinitic clay mineralogy. The objective of the present study was to quantify the pseudo total concentrations of Cd, Co, Cu, Cr, Mn, Ni, Zn and Fe in Xhantic Udox and Xhantic Udult soils derived from these sediments. The reference sites were covered by native vegetation and located in the States of Pará and Amapá, Brazil. Multiple linear regression analysis was applied to determine correlations between soil parameters and the levels of these metals. The best correlation was obtained between Fe, Mn, clay, and silt contents, and Cd, Co, Cu, Zn, Cr, Ni. A correlation between pH and these metal levels was not found. Clay and sand contents showed a negative inverse correlation with the metal levels,of same magnitude but with a different sign; this was the reason for excluding one of the parameters in the regression model. In general, the contents of the elements were lower than those found in soils formed from other parent materials. The Mn content was included in the model of multiple linear regression for Cd and Co, due to its association with these last metals. Silt level showed to have a significant influence in the equations for Cr and Co, which is attributed to the presence of clay minerals and Fe and Mn oxides in ferruginous and clay aggregates of silt size. The equations obtained in this paper, are useful to predict, in general terms, the amounts of those heavy metals in an unknown soil sample, if the soil material were not contaminated or affected by land usage. Thus, they may be applied to evaluate soil contamination by the studied heavy metals

Chemical amendment and phytostabilization of an industrial residue contaminated with Zn and Cd

Phytostabilisation of a contaminated soil with heavy metals is considered a very appropriate technology to reduce erosion and dispersion of contaminants. A greenhouse study was conducted to evaluate the effects of both chemical amendments (calcium silicate and brewery sludge), and phytoremediation using the grass Brachiaria decumbens, on an industrial residue contaminated with Zn and Cd (industrial residue). Industrial residue samples placed into 30 L containers were amended with 20% brewery sludge, calcium silicate (2%, 3%), and 20% of brewery sludge + calcium silicate (2.5%, 4%), and were compared to the control treatment (non-amended residue). After pH stabilization, B. decumbens plants were grown on all treatments in order to evaluate the ability of the species to tolerate high Zn and Cd concentrations from the residue. Samples were collected twice, at planting and harvesting, for pH determination and simple extractions with water, sodium nitrate, acetic acid and DTPA. Differences in Zn and Cd concentrations in extracts allowed to estimate the concentrations of these elements in the most likely chemical forms they are found in the residue. Alkaline and organic industrial amendments reduced Zn and Cd percentages, both in the soluble and exchangeable fractions, as well as caused the predominance of Zn and Cd in the most stable chemical fractions, such as complexed and precipitated compounds. B. decumbens was tolerant to Zn and Cd from the industrial residue after addition of the amendments.A fitoestabilização de solos contaminados com metais pesados é considerada uma boa alternativa para reduzir a erosão e dispersão de contaminantes no ambiente. Foi conduzido um experimento em casa-de-vegetação com o objetivo de avaliar a contenção química (silicato de cálcio e lodo do biodigestor de uma cervejaria) e a fitorremediação pela Brachiaria decumbens, de um resíduo industrial contaminado com Zn e Cd, utilizando vasos de 30 L. Os tratamentos foram: resíduo industrial (testemunha); resíduo industrial + 20% lodo; resíduo industrial + silicato de cálcio (2%; 3%); (resíduo industrial + 20% lodo) + silicato de cálcio (2,5%; 4%). Após estabilização do pH, foram cultivados nos tratamentos plantas de B. decumbens, visando avaliar o potencial de tolerância a elevadas concentrações de Zn e Cd presentes no resíduo industrial. No plantio e colheita das plantas foram retiradas amostras dos diferentes tratamentos para determinação do pH e extrações simples com água, nitrato de sódio, ácido acético e DTPA. A partir das concentrações de Zn e Cd obtidas nas extrações, foram estimadas, através das diferenças nas quantidades extraíveis, as concentrações de Zn e Cd nas prováveis formas químicas. A adição de resíduos industriais, alcalino e orgânico, provocou redução nas percentagens de Zn e Cd nas frações solúvel e trocável, e predominância dos mesmos em frações químicas mais estáveis como complexados e precipitados. A B. decumbens apresentou tolerância ao Zn e Cd presentes no resíduo industrial após tratamento de contenção química

Uso de resíduos industriais na remediação de solo contaminado com cádmio e zinco

This study aimed to evaluate the use of two types of industrial waste to reduce availability of zinc and cadmium in contaminated soil. The experiment was conducted in a greenhouse at the Universidade Federal Rural do Rio de Janeiro during 225 days, using a substrate contaminated with zinc and cadmium, collected from the yard of the Itaguaí Port Mining Industry, and near the site of disposal of hazardous waste from two industries, Cia Mercantil and Industrial Inga in Itaguaí. The substrate was treated with two inerting agents: an industrial residue with characteristic alkaline (Slag of Melt Shop) in two doses, 4% and 6%, and a high content of iron oxide as adsorbent (lamination of scale) in a single dose of 1%. After planting the seedlings of Eucalyptus urophylla, substrate was collected from each experimental unit to determine the bioavailable and unavailable fractions (extracted with MgCl2). The substrate, untreated, had a high content of cadmium and zinc in the bioavailable fraction. The treatments caused a reduction in the availability of these elements in the soil, as evidenced in the differential absorption by plants. Due to the increased availability of cadmium and zinc in the soil without the addition of inerting agents, plants did not survive the high levels of these elements, and died 30 days after implantation of the experiment. The dry matter yield was positively influenced by the application of inerting agents, showing better response at higher slag. The highest dose also gave the lowest concentrations of elements in plants without causing nutrient deficiency of zinc and cadmium, maintaining levels that are not toxic to the species of eucalyptus. Although showing lower concentrations of cadmium at 6% Melt Shop Slag, this dose resulted in greater extraction of this element by plants.Este trabalho teve como objetivo avaliar a utilização de dois resíduos industriais na redução de disponibilidade de zinco e cádmio em solo contaminado. O experimento foi conduzido em casa de vegetação na Universidade Federal Rural do Rio de Janeiro por 225 dias, utilizando-se um substrato contaminado com zinco e cádmio, coletado no pátio de minério do Porto de Itaguaí, e próximo ao local de disposição de resíduo perigoso da Cia Mercantil e Industrial Ingá em Itaguaí, RJ. O substrato foi tratado com dois agentes inertizantes, assim descritos: um resíduo industrial com característica alcalina (Escória de Aciaria) em duas doses 4 e 6%, e outro com alto teor de óxido de ferro como adsorvente (Carepa de Laminação), em dose única de 1%. Após o plantio das mudas de Eucalyptus urophylla, foram feitas coletas do substrato em cada unidade experimental para determinação das frações biodisponíveis (extraído com MgCl2) e a não disponível. O substrato não tratado apresentava alto teor de cádmio e zinco na fração biodisponível. Os tratamentos causaram uma redução na disponibilidade desses elementos no solo, evidenciado na absorção diferenciada pelas plantas. Por causa da maior disponibilidade do cádmio e zinco no solo sem adição dos inertizantes, as plantas não resistiram aos altos teores desses elementos e morreram 30 dias após a implantação do experimento. A produção de massa seca foi influenciada positivamente pela aplicação dos agentes inertizantes, apresentando melhor resposta na maior dose de escória de aciaria. A maior dose também propiciou as menores concentrações dos elementos nas plantas, sem provocar deficiência do micronutriente zinco e mantendo o cádmio a níveis não tóxicos para as espécies de eucalipto. Apesar de apresentar menores concentrações de cádmio na dose de 6% de Escória de Aciaria,essa dose resultou na maior extração desse elemento pelas plantas

Use of industrial waste to reduce the toxicicity of cadmium and zinc in contaminated soils

Este trabalho teve como objetivo avaliar a utiliza\ue7\ue3o de dois res\uedduos industriais na redu\ue7\ue3o de disponibilidade de zinco e c\ue1dmio em solo contaminado. O experimento foi conduzido em casa de vegeta\ue7\ue3o na Universidade Federal Rural do Rio de Janeiro por 225 dias, utilizando-se um substrato contaminado com zinco e c\ue1dmio, coletado no p\ue1tio de min\ue9rio do Porto de Itagua\ued, e pr\uf3ximo ao local de disposi\ue7\ue3o de res\uedduo perigoso da Cia Mercantil e Industrial Ing\ue1 em Itagua\ued, RJ. O substrato foi tratado com dois agentes inertizantes, assim descritos: um res\uedduo industrial com caracter\uedstica alcalina (Esc\uf3ria de Aciaria) em duas doses 4 e 6%, e outro com alto teor de \uf3xido de ferro como adsorvente (Carepa de Lamina\ue7\ue3o), em dose \ufanica de 1%. Ap\uf3s o plantio das mudas de Eucalyptus urophylla , foram feitas coletas do substrato em cada unidade experimental para determina\ue7\ue3o das fra\ue7\uf5es biodispon\uedveis (extra\ueddo com MgCl2) e a n\ue3o dispon\uedvel. O substrato n\ue3o tratado apresentava alto teor de c\ue1dmio e zinco na fra\ue7\ue3o biodispon\uedvel. Os tratamentos causaram uma redu\ue7\ue3o na disponibilidade desses elementos no solo, evidenciado na absor\ue7\ue3o diferenciada pelas plantas. Por causa da maior disponibilidade do c\ue1dmio e zinco no solo sem adi\ue7\ue3o dos inertizantes, as plantas n\ue3o resistiram aos altos teores desses elementos e morreram 30 dias ap\uf3s a implanta\ue7\ue3o do experimento. A produ\ue7\ue3o de massa seca foi influenciada positivamente pela aplica\ue7\ue3o dos agentes inertizantes, apresentando melhor resposta na maior dose de esc\uf3ria de aciaria. A maior dose tamb\ue9m propiciou as menores concentra\ue7\uf5es dos elementos nas plantas, sem provocar defici\ueancia do micronutriente zinco e mantendo o c\ue1dmio a n\uedveis n\ue3o t\uf3xicos para as esp\ue9cies de eucalipto. Apesar de apresentar menores concentra\ue7\uf5es de c\ue1dmio na dose de 6% de Esc\uf3ria de Aciaria,essa dose resultou na maior extra\ue7\ue3o desse elemento pelas plantas.This study aimed to evaluate the use of two types of industrial waste to reduce availability of zinc and cadmium in contaminated soil. The experiment was conducted in a greenhouse at the Universidade Federal Rural do Rio de Janeiro during 225 days, using a substrate contaminated with zinc and cadmium, collected from the yard of the Itagua\ued Port Mining Industry, and near the site of disposal of hazardous waste from two industries, Cia Mercantil and Industrial Inga in Itagua\ued. The substrate was treated with two inerting agents: an industrial residue with characteristic alkaline (Slag of Melt Shop) in two doses, 4% and 6%, and a high content of iron oxide as adsorbent (lamination of scale) in a single dose of 1%. After planting the seedlings of Eucalyptus urophylla, substrate was collected from each experimental unit to determine the bioavailable and unavailable fractions (extracted with MgCl2). The substrate, untreated, had a high content of cadmium and zinc in the bioavailable fraction. The treatments caused a reduction in the availability of these elements in the soil, as evidenced in the differential absorption by plants. Due to the increased availability of cadmium and zinc in the soil without the addition of inerting agents, plants did not survive the high levels of these elements, and died 30 days after implantation of the experiment. The dry matter yield was positively influenced by the application of inerting agents, showing better response at higher slag. The highest dose also gave the lowest concentrations of elements in plants without causing nutrient deficiency of zinc and cadmium, maintaining levels that are not toxic to the species of eucalyptus. Although showing lower concentrations of cadmium at 6% Melt Shop Slag, this dose resulted in greater extraction of this element by plants

Comportamento da Cordia africana Lam. cultivada em solo contaminado por metais pesados e tratado com materiais amenizantes

http://dx.doi.org/10.5902/1980509810544This study aimed to evaluate the remediation of two soils contaminated with heavy metals from soil excavations, located near the port of Itaguaí, through the techniques of chemical immobilization and phytostabilization using the species Cordia africana. The data were collected in the ore courtyard from ‘Companhia Siderúgica Nacional’ (CSN), in the port of Itaguaí, Rio de Janeiro state. In order to reduce the solubility of heavy metals present in these substrates, two industrial waste products produced by CSN were used as ameliorating products, the steelmaking slag and the mill scale, in different concentrations. The plant species was considered with potential to be used in programs of phytostabilization, due to its heavy metal tolerance studied and to high accumulation of such elements in roots and stem. In the substrate of low combination, the lowest accumulation of Zinc and Cadmium in stems and leaves occurred with the use of 4% of soothing. In the substrate of high accumaltion it was 6%. http://dx.doi.org/10.5902/1980509810544Este trabalho teve como objetivo avaliar a remediação de dois solos contaminados com metais pesados, provenientes de escavações de solo localizado próximo ao porto de Itaguaí, mediante as técnicas de imobilização química e da fitoestabilização utilizando da espécie Cordia africana. Os dados foram coletados no pátio de minério da Companhia Siderúrgica Nacional (CSN), no Porto de Itaguaí–RJ. Visando reduzir a solubilidade de metais pesados presentes nestes substratos, foram utilizados como amenizantes dois resíduos industriais produzidos pela CSN, a Escória de Aciaria e a Carepa de Laminação, em diferentes concentrações. A espécie vegetal foi considerada com potencial para ser utilizada em programas de fitoestabilização, devido à sua tolerância aos metais pesados estudados e ao maior acúmulo desses elementos nas raízes e no caule. No substrato com baixa contaminação o menor acúmulo de Zinco e Cádmio no caule e folhas ocorreu com o emprego de 4% de amenizante, e no de alta com 6%

Inconsistent Adoption of World Health Organization V (2010) Semen Analysis Reference Ranges in the United States Six Years After Publication

Objective To determine the percentage of laboratories in the United States that have adopted the World Health Organization 2010 (WHO 5) semen analysis (SA) reference values six years after their publication. Methods Laboratories were identified via three approaches: using the Clinical Laboratory Improvement Amendments (CLIA) website, the CDC's 2015 Assisted Reproductive Technology Fertility Clinical Success Rate Report, and automated web searches. Laboratories were contacted by phone or email to obtain de-identified SA reports and reference ranges. Results We contacted 617 laboratories in 46 states, of which 208 (26.7%) laboratories in 45 states were included in our analysis. 132 (63.5%) laboratories used WHO 5 criteria, 57 (27.4%) used WHO 4 criteria, and 19 (9.1%) used other criteria. WHO 5 criteria adoption rates varied by geographic region, ranging from 87.5% (35/40) in the Midwest to 50.0% (33/66) in the West. There was a greater adoption rate of WHO 5 reference values in academic affiliated (23/26, 88.5%) compared to non-academic affiliated laboratories (110/182, 60.4%) (P=0.028). Conclusion While the majority of laboratories have adopted WHO 5 criteria following its release six years ago, a large percentage (36.5%) use what is now considered outdated criteria. This variability could result in the characterization of a male's semen values as being “within reference range” at one center and “outside of reference range” at another. This inconsistency in classification may result in confusion for the both patient and physician and potentially shift the burden of infertility evaluation and treatment to the female partner

Perturbations of Noise: The origins of Isothermal Flows

We make a detailed analysis of both phenomenological and analytic background for the "Brownian recoil principle" hypothesis (Phys. Rev. A 46, (1992), 4634). A corresponding theory of the isothermal Brownian motion of particle ensembles (Smoluchowski diffusion process approximation), gives account of the environmental recoil effects due to locally induced tiny heat flows. By means of local expectation values we elevate the individually negligible phenomena to a non-negligible (accumulated) recoil effect on the ensemble average. The main technical input is a consequent exploitation of the Hamilton-Jacobi equation as a natural substitute for the local momentum conservation law. Together with the continuity equation (alternatively, Fokker-Planck), it forms a closed system of partial differential equations which uniquely determines an associated Markovian diffusion process. The third Newton law in the mean is utilised to generate diffusion-type processes which are either anomalous (enhanced), or generically non-dispersive.Comment: Latex fil

Hadroproduction of the Chi1 and Chi2 States of Charmonium in 800 GeV/c Proton-Silicon Interactions

The cross sections for the hadroproduction of the Chi1 and Chi2 states of charmonium in proton-silicon collisions at sqrt{s}=38.8 GeV have been measured in Fermilab fixed target Experiment 771. The Chi states were observed via their radiative decay to J/psi+gamma, where the photon converted to e+e- in the material of the spectrometer. The measured values for the Chi1 and Chi2 cross sections for x_F>0 are 263+-69(stat)+-32(syst) and 498+-143(stat)+-67(syst) nb per nucleon respectively. The resulting sigma(Chi1}/sigma(Chi2) ratio of 0.53+-0.20(stat)+-0.07(syst), although somewhat larger than most theoretical expectations, can be accomodated by the latest theoretical estimates.Comment: 4 pages, 4 figure

The frequency partitioned block modified filtered-x NLMS with orthogonal correction factors for multichannel Active Noise Control

The Normalized Least Mean Square (NLMS) algorithm with a filtered-x structure (FxNLMS) is a widely used adaptive algorithm for Active Noise Control (ANC) due to its simplicity and ease of implementation. One of the major drawbacks is its slow convergence. A modified filtered-x structure (MFxNLMS) can be used to moderately improve the speed of convergence, but it does not offer a huge improvement. A greater increase in the speed of convergence can be obtained by using the MFxNLMS algorithm with orthogonal correction factors (M-OCF), but the usage of orthogonal correction factors also increases the computational complexity and limits the usage of the M-OCF in massive real-time applications. However, Graphics Processing Units (GPUs) are well known for their potential for highly parallel data processing. Therefore, GPUs seem to be a suitable platform to ameliorate this computational drawback. In this paper, we propose to derive the M-OCF algorithm to a partitioned block-based version in the frequency domain (FPM-OCF) for multichannel ANC systems in order to better exploit the parallel capabilities of the GPUs. The results show improvements in the convergence rate of the FPM-OCF algorithm in comparison to other NLMS-type algorithms and the usefulness of CPU devices for developing versatile, scalable, and low-cost multichannel ANC systems. (C) 2015 Elsevier Inc. All rights reserved.Lorente Giner, J.; Ferrer Contreras, M.; Diego Antón, MD.; Gonzalez, A. (2015). The frequency partitioned block modified filtered-x NLMS with orthogonal correction factors for multichannel Active Noise Control. Digital Signal Processing. 43:47-58. doi:10.1016/j.dsp.2015.05.003S47584