Consulta: subjectFacets:"Humic acid"
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Data/hora: 11/06/2024 06:30:30

Stimulation of nitrogen-fixing cyanobacteria in a Baltic Sea plankton community by land-derived organic matter or iron addition
Provedor de dados: 5
Autores: Stolte, Willem; Balode, Maija; Carlsson, Per; Grzebyk, Daniel; Janson, Sven; Lips, Inga; Panosso, Renata; Ward, Clive J.; Graneli, Edna.
In the Baltic Sea, floating blooms of nitrogen-fixing cyanobacteria occur yearly during late summer. These blooms can sometimes be limited by iron. Due to extensive foresting around the Baltic Sea, iron is entering the Baltic Sea partly bound to dissolved organic material (DOM) via rivers. An experiment was performed in 300 1 laboratory mesocosms to test the hypothesis that riverine high-molecular weight dissolved organic matter (HMWDOM), extracted by tangential flow filtration &gt; 1000 Da, stimulates the biomass of nitrogen-fixing cyanobacteria, by increasing the availability of iron. The addition of iron/EDTA and of DOM resulted in 5 to 10 times higher biomass of nitrogen-fixing cyanobacteria. Accordingly, higher primary production and particulate...
Tipo: Text
Palavras-chave: Mesocosm experiment; Humic acid; HMWDOM; High molecular weight dissolved organic matter; Iron; Nitrogen fixation; Cyanobacteria.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2470.pdf

圃場還元利用されている実際的な牛ふん尿堆肥に含まれる腐植酸およびフルボ酸の化学的特徴
Provedor de dados: 19
Autores: 李, 香珍; 谷, 昌幸; 相内, 大吾; 小池, 正徳; 倉持, 勝久; LI, Xiangzhen; TANI, Masayuki; AIUCHl, Daigo; KOIKE, Masanori; KURAMOCHI, Katsuhisa.
本研究では，堆肥化の進行や腐熟度が大きく異なる牛ふ ん尿堆肥について，堆肥製造業者や一般の畜産農家および畑作農家が製造し，かつ圃場還元している実際的な堆肥を対象に，牛ふん尿の堆肥化と腐熟化に伴う腐植酸およびフルボ酸の化学的特徴，および腐植酸のスペクトル解析から構造単位の存在割合の違いを明らかにした.さらに土壌中での可動性が異なると考えられる腐植を水および水酸化ナトリウム溶液により抽出して比較し，その化学的特徴や構造単位の違いを明らかにした. 堆肥化期聞が異なる牛ふん尿バーク堆肥では，堆肥化による腐熟化の進行に伴って，沈殿部割合や腐植酸の相対色度(RF値)が増加した. 堆肥化および腐熟化の程度が異なる4種類の牛ふん尿堆 肥から水酸化ナトリウム溶液および水により抽出された腐植酸とフルボ酸の光学的特性を比較した.水酸化ナトリウム溶液では，堆肥化や腐熟化がほとんど進行していないと判断された高水分乳牛ふん尿堆肥から極めて未熟なRp型腐植酸が抽出され，牛ふん中の未消化繊維や敷料などの植物腐朽遺体に由来するリグニンなどの成分に由来すると考えられた.腐熟化の進行が認められた肉牛ふん尿敷料堆肥や肉牛ふん尿敷料と鶏糞との混合堆肥では，好気的な発酵と温度上昇に伴って生成した腐植化の進んだ腐植酸が含まれていると考えられ，とくに腐熟度の高かった鶏糞との混合堆肥からB型腐植酸が抽出された.水抽出では，水酸化ナトリウム溶液による抽出よりも腐植の抽出割合が低かったが，水抽出された腐植酸のRF値は水酸化ナトリウム溶液で抽出された腐植酸よりも高かった. 紫外可視吸収スペクトルおよびフーリエ変換赤外吸収ス...
Palavras-chave: 牛ふん尿堆肥; 圃場還元; 腐植酸; フルボ酸; FT-IRスペクトル; Cattle manure; Field application; Humic acid; Fulvic acid; Fourier-transform; Infrared(FT-IR) spectra.
Ano: 2009
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2697

The use of total luminescence spectroscopy in the investigation of the effects of different rice management practices on humic substances of a planosol
Provedor de dados: 90
Autores: Olendzki,Rodrigo Nogueira; Ignácio,Andréia Christina; Mangrich,Antonio Salvio.
In the Earth's carbon cycle, C stocks in the soil are higher than in vegetation and atmosphere. Maintaining and conserving organic C concentrations in the soil by specific management practices can improve soil fertility and productivity. The aim of this study was to evaluate the impact of agricultural management techniques and influence of water regime (flooded or drained) on the structure of humic substances by excitation/emission matrix fluorescence. Six samples of a Planosol (Planossolo by the Brazilian System of Soil Classification) were collected from a rice field. Humic substances (HS) were extracted from flooded and drained soil under different agricultural management techniques: conventional tillage, reduced tillage and grassland. Two peaks at a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fulvic acid; Humic acid; Total luminescence spectroscopy.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000500008

Solubility of Heavy Metals/Metalloid on Multi-Metal Contaminated Soil Samples from a Gold Ore Processing Area: Effects of Humic Substances
Provedor de dados: 90
Autores: Boechat,Cácio Luiz; Pistóia,Vítor Caçula; Ludtke,Ana Cristina; Gianello,Clesio; Camargo,Flávio Anastácio de Oliveira.
ABSTRACT Bioavailability of heavy metals at contaminated sites is largely controlled by the physicochemical properties of the environmental media such as dissolved organic matter, hydroxides and clay colloids, pH, soil cation exchange capacity and oxidation-reduction potential. The aim of this study was to investigate soil pH and heavy metal solubility effect by levels of humic and fulvic acids applied in soil samples with different levels of contamination by heavy metals. The soil samples used in this study were collected in a known metal-contaminated site. Humic acid (HA) and fulvic acid (FA) were purchased as a commercially available liquid material extracted from Leonardite. The experiment was carried out in a factorial scheme of 4 × (4 + 1), with four...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Soil pH; Bioavailable metal; Humic acid; Fulvic acids; Metal leaching.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100528

Nutritional status, production and fruit quality of west indian cherry fertigated with nitrogen and humic substance
Provedor de dados: 94
Autores: Dias,Dayanne do Nascimento; Sousa,Karla dos Santos Melo de; Lima,Augusto Miguel Nascimento; Cavalcante,Ítalo Herbert Lucena; Santos,Laura Paula Araújo dos; Cunha,Jailson Cavalcante.
Abstract  Information on humic substances (HS) associated with nitrogen fertilization in West Indian cherry is scarce in the literature. The use of soil conditioners, such as HS, can increase the efficiency in the absorption of nutrients, especially N. Therefore, the present study aimed to evaluate, in two production cycles, the fruit quality, yield and nutritional status of West Indian cherry as a function of fertigation with nitrogen (N) and HS in Petrolina-PE, Brazil. The experimental design was in split plots, with treatments distributed in 5 x 2 strips, referring to N doses (50, 75, 100, 125 and 150% of the recommended dose) and HS application (without and with), respectively, with 4 replicates and 3 plants per plot. The N source used was urea (45% N)...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Malpighia emarginata; Plant nutrition; Nitrogen fertilization; Humic acid; Production.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452020000203002

Effect of humic acid on survival, ionoregulation and hematology of the silver catfish, Rhamdia quelen (Siluriformes: Heptapteridae), exposed to different pHs
Provedor de dados: 103
Autores: Costa,Silvio T. da; Gressler,Luciane T.; Sutili,Fernando J.; Loebens,Luíza; Lazzari,Rafael; Baldisserotto,Bernardo.
This study evaluates whether humic acid (HA; Aldrich) protects the silver catfish, Rhamdia quelen (Quoy &amp; Gaimard, 1824), against exposure to acidic pH. Survival, levels of Na+, Cl- and K+ plasma, hematocrit, hemoglobin and erythrocyte morphometry were measured. Fish were exposed to 0, 10, 25 and 50 mg L 1 HA at four pH levels: 3.8, 4.0, 4.2 and 7.0 up to 96 hours. None of the fish exposed to pH 3.8 survived for 96 hours into the experiment, and survival of fish subjected to pH 4.0 decreased when HA concentration increased. Plasma Na+ levels decreased when pH was acidic, with no influence of HA, while Cl- levels declined at low pH with increased HA concentration. The levels of K+ at pH 4.0 and 4.2 increased without HA. Hematocrit and hemoglobin...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Blood parameters; Humic acid; Plasma ion levels; Survival.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702015000300215

Roots of ‘BRS Princesa’ banana fertigated with humic substances and saponin-based plant extracts
Provedor de dados: 1
Autores: Coelho, Eugênio Ferreira; Melo, Diego Magalhães de; Pereira, Bruno Laecio da Silva; Santos, Djalma Barbosa dos; Rosa, Raul Castro Carriello.
This study aimed to evaluate the effects of fertigation with humic substances, with and without the addition of plant extracts, on the root system of the 'BRS Princesa' banana cultivar. The banana crop was cultivated at a spacing of 2.0 x 2.5 m and fertigated using a drip system in a dystrocohesive Yellow Latosol. The experimental design was randomized blocks, in a split-split-plot scheme with five replicates, for the following factors: humic substance doses and presence of a plant extract formulation. The treatments consisted of five doses of humic substances, based on a reference dose of 14.14 L ha-1 cycle-1, in the presence and absence of plant extract. The variable root length (cm) was subjected to variance analyses to evaluate the effect of the humic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: 5.03.02.02-7 Musa spp.; Root length; Humic acid; Fulvic acid. Conservação do solo e fertirrigação.
Ano: 2016
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/30790

Desempenho e desenvolvimento ruminal em resposta ao fornecimento de substâncias húmicas para bezerros leiteiros em sistema de desaleitamento precoce - doi: 10.4025/actascianimsci.v33i4.10907
Provedor de dados: 2
Autores: Silva, Jackeline Thais da; ESALQ/USP; Bittar, Carla Maris Machado; ESALQ - USP; Ferreira, Lucas Silveira; ESALQ/USP.
O objetivo deste estudo foi avaliar a inclusão de substâncias húmicas na dieta sobre o desempenho e o desenvolvimento ruminal de bezerros leiteiros da raça Holandesa. Foram utilizados 20 animais em delineamento experimental em blocos completos aleatorizados, distribuídos nos seguintes tratamentos: 1) controle; 2) substâncias húmicas, via concentrado inicial. Os animais receberam 4 L d-1 da dieta líquida e concentrado inicial ad libitum. Diariamente foram realizadas análise de escore fecal, e semanalmente foram realizadas pesagens, medidas de crescimento corporal e colheita de sangue para a determinação de glicose, N-ureico e β-hidroxibutirato (BHBA). Os animais foram desaleitados na oitava semana de idade e foram abatidos para análise do desenvolvimento do...
Tipo: Pesquisa de campo
Palavras-chave: Produção animal  criação de animais ácido fúlvico; Ácido húmico; Escore fecal; Papilas ruminais fulvic acid; Humic acid; Fecal score; Ruminal papillae.
Ano: 2011
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/10907

Urease activity according to the different inhibitors
Provedor de dados: 42
Autores: GOMES,MATEUS P.; ZONTA,EVERALDO; STAFANATO,JULIANO B.; PEREIRA,ARIANA M.
Abstract The objective of this study was to evaluate NBPT, zeolite and humic acid in different concentrations as inhibitors of the activity of the enzyme urease. The activity of the urease enzyme was quantified by the methods proposed by May and Douglas (1976) and Witte and Medina-Escobar (2001). For this reason, two experiments were conducted in a completely randomized design in split plots, in which the incubation periods are the plots and the fertilizers with the inhibitors at the different concentrations are the subplots with three replications. Fifteen fertilizers based on NBPT-coated urea, humic acid and zeolite were used in different concentrations. The two methods of analysis used in the experiment confirmed the efficiency of NBPT in inhibiting the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Humic acid; Nbpt; Zeolite; Urea.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000703685

Quantitative differentiation between soil organic carbon and biochar carbon in Aridisol
Provedor de dados: 118
Autores: Lara,Nelson; Figueroa,Leonardo; Carvajal,Fabiola; Zapata,Yubinza; Urbina,Camilo; Escobar,Hugo.
N. Lara, L. Figueroa, F. Carvajal, Y. Zapata, C. Urbina, and H. Escobar. 2013. Quantitative differentiation between soil organic carbon and biochar carbon in Aridisol. Cien. Inv. Agr. 40(2): 387-395. To understand the effect of biochar, identify its presence and quantify its stability in soil, it is necessary to differentiate between the two main sources of carbon. These sources are resident soil organic matter and biochar, which is produced by burning organic matter under low oxygen concentration in a process known as pyrolysis. The present study employs solid-liquid extraction with an alkaline solution, the efficiency of which was improved by a reflux system and quantification using the modified Walkley-Black method, to distinguish the two carbon sources...
Tipo: Journal article
Palavras-chave: Alkaline extraction; Differentiate; Humic acid; Organic carbon.
Ano: 2013
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202013000200013