Effect of organic manures and humic acids on changes in hydrolysable organic fractions of ni­trogen in a Typic Haploumbrepts soil

AGROCHIMICA ◽  
2019 ◽  
pp. 3-14
Author(s):  
G. Nongmeikapam ◽  
N. Surbala Devi
Keyword(s):  
Humic Acids ◽  
Organic Manures ◽  
Organic Fractions

Tracing Carbon Isotope Variations in Lake Sediments Caused by Environmental Factors During the Past Century: A Case Study of Lake Tapeliai, Lithuania

Radiocarbon ◽  
2019 ◽  
Vol 61 (4) ◽  
pp. 885-903 ◽  
Author(s):  
Rūta Barisevičiūtė ◽  
Evaldas Maceika ◽  
Žilvinas Ežerinskis ◽  
Jonas Mažeika ◽  
Laurynas Butkus ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Humic Acids ◽  
Isotope Composition ◽  
Stable Carbon Isotope ◽  
Hard Water ◽  
Lake Ecosystem ◽  
Past Century ◽  
Stable Carbon ◽  
Organic Fractions ◽  
Reservoir Age

ABSTRACTIn this study, we examined how land use and urbanization changes in adjacent areas affected biological productivity and carbon cycling in a lake ecosystem over 100 years and how these changes are reflected in carbon isotope variations. We performed radiocarbon (14C) activity and stable carbon isotope ratio analysis in two organic fractions: humin and humic acids of lake sediment. Additionally, we performed pigment and diatom analysis and determined the carbonate and organic matter (OM) content in sediments. Over the last century, the estimated 14C reservoir age in both sediment organic fractions varied from 1136 ± 112 yr to 5733 ± 122 yr. The increase in the reservoir age by 1175 ± 111 yr was related with higher inputs of pre-aged organic carbon and 14C depleted hard water due to the opening of the channel connecting two lakes. Nuclear weapons tests caused an increase in the reservoir age of up to 5421 ± 135 yr and 5733 ± 122 yr in humin and humic acids, respectively. 13C values in the humic acid fraction showed a tendency to decrease, depending on the content of autochthonous versus allochthonous OM in sediments, while changes in the sources of OM had a minor impact on the stable carbon isotope composition in the humin fraction.

CHARACTERISTICS OF ORGANIC MATTER IN DEGRADING CHERNOZEMIC SURFACE SOILS

1963 ◽  
Vol 43 (2) ◽  
pp. 275-286 ◽  
Author(s):  
C. D. Sawyer ◽  
S. Pawluk
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Organic Carbon ◽  
Humic Acids ◽  
Acid Content ◽  
Organic Carbon Content ◽  
Total Acidity ◽  
Organic Fraction ◽  
Organic Debris ◽  
Organic Fractions

Humic acids, polysaccharides, and polyuronides were extracted from samples representative of the organic and mineral A horizons of two Dark Grey Wooded soils. These organic fractions were characterized in order to determine the alterations, if any, which may be evident in some of the organic constituents present at varying depths in the organic and mineral A horizons as a result of progressive podzolic degradation.Humic acid content in the organic fraction was found to decrease with depth in the mineral A horizon. Methoxyl content of the purified humic acids averaged 0.26 me./g. and decreased with depth while the total acidity (phenolic and carboxyl acidity) averaged 7.6 me./g. and increased with depth. Nitrogen content of the purified humic acids averaged 2.6 per cent and was relatively constant throughout the organic and mineral A horizons. The humic acid content of the undecomposed and semi-decomposed organic debris was found to be only slightly lower than that of the Ah horizon. This was probably at least partially due to hydrolyses of organic matter during the harsh extraction of humic acids with warm 1.0 N NaOH.Total polysaccharide and polyuronide content of these soils decreased rapidly with depth; however, this decrease paralleled the decrease in total organic carbon content.

scholarly journals Heavy metal distribution between fractions of humic substances in heavily polluted soils

2011 ◽  
Vol 50 (No. 8) ◽  
pp. 339-345 ◽  
Author(s):  
L. Borůvka ◽  
O. Drábek
Keyword(s):  
Heavy Metal ◽  
Humic Substances ◽  
Humic Acids ◽  
Fulvic Acids ◽  
Humic And Fulvic Acids ◽  
Polluted Soils ◽  
Traditional Procedure ◽  
Zn Content ◽  
Organic Fractions ◽  
Potential Mobility

Soil organic matter is important in controlling heavy metal behaviour in soils. This study aims to determine the distribution of organically bound Cd, Pb, and Zn between humic and fulvic acids in 20 samples of heavily polluted Fluvisols. Traditional procedure of alkaline sodium hydroxide/pyrophosphate extraction of humic substances with consequent humic acids precipitation by acidification was used. All of the three metals were bound predominantly on fulvic acids (mean share was 98.4, 82.0, and 95.7% of total organically bound Cd, Pb, and Zn content, respectively). Mainly the level of pollution controlled the amount of metals bound on fulvic acids. On humic acids, a limited amount of specific sorption sites for the metals is expected. Lead content bound on humic acids was negatively correlated with soil pH. The results suggest relatively high potential mobility of organic fractions of heavy metals in soils under this study. The selectivity of alkaline extracting agent is briefly discussed.

ROLE OF ADDED PHOSPHOGYPSUM AND HUMIC ACIDS IN THE KINETIC RELEASE OF SALT FROM SALT AFFECTED SOIL (SALINE – SODIC)

2020 ◽  
pp. 15-27
Keyword(s):  
Electrical Conductivity ◽  
Humic Acids ◽  
Release Rate ◽  
Release Kinetics ◽  
Sodium Adsorption Ratio ◽  
Salt Affected Soil ◽  
Two Factors ◽  
Dissolved Ions ◽  
Kinetic Release

In order to study the effect of phosphogypsum and humic acids in the kinetic release of salt from salt-affected soil, a laboratory experiment was conducted in which columns made from solid polyethylene were 60.0 cm high and 7.1 cm in diameter. The columns were filled with soil so that the depth of the soil was 30 cm inside the column, the experiment included two factors, the first factor was phosphogypsum and was added at levels 0, 5, 10 and 15 tons ha-1 and the second-factor humic acids were added at levels 0, 50, 100 and 150 kg ha-1 by mixing them with the first 5 cm of column soil and one repeater per treatment. The continuous leaching method was used by using an electrolytic well water 2.72 dS m-1. Collect the leachate daily and continue the leaching process until the arrival of the electrical conductivity of the filtration of leaching up to 3-5 dS m-1. The electrical conductivity and the concentration of positive dissolved ions (Ca, Mg, Na) were estimated in leachate and the sodium adsorption ratio (SAR) was calculated. The results showed that the best equation for describing release kinetics of the salts and sodium adsorption ratio in soil over time is the diffusion equation. Increasing the level of addition of phosphogypsum and humic acids increased the constant release velocity (K) of salts and the sodium adsorption ratio. The interaction between phosphogypsum and humic acids was also affected by the constant release velocity of salts and the sodium adsorption ratio. The constant release velocity (K) of the salts and the sodium adsorption ratio at any level of addition of phosphogypsum increased with the addition of humic acids. The highest salts release rate was 216.57 in PG3HA3, while the lowest rate was 149.48 in PG0HA0. The highest release rate of sodium adsorption ratio was 206.09 in PG3HA3, while the lowest rate was 117.23 in PG0HA0.

Peculiarities of the Influence of Humic Acids on the Development of Plankton Algae

2011 ◽  
Vol 47 (1) ◽  
pp. 97-104
Author(s):  
V. A. Medved' ◽  
P. D. Klochenko ◽  
O. V. Vasilenko ◽  
T. A. Vasilchuk
Keyword(s):  
Humic Acids

Changes in the Humic Acid–Metal Complexation Characteristics Depending on Humification Degree / Humīnskābju – Metālu Kompleksveidošanās Rakstura Izmaiņas Atkarībā No Humifikācijas Pakāpes

2012 ◽  
Vol 51 (3) ◽  
pp. 228-237
Author(s):  
D. Dudare ◽  
M. Klavins
Keyword(s):  
Humic Acid ◽  
Stability Constants ◽  
Humic Acids ◽  
Complex Stability ◽  
Peat Layer ◽  
Raised Bog ◽  
Complexing Capacity ◽  
Humification Degree ◽  
Complexation Process ◽  
Complex Stability Constants

The aim of this study is to determine the Cu(II) complexing capacity and stability constants of Cu(II) complexes of humic acids isolated from two well-characterized raised bog peat profiles in respect to the basic properties and humification characteristics of the studied peats and their humic acids. The complex stability constants significantly change within the studied bog profiles and are well correlated with the age and decomposition degree of the peat layer from which the humic acids have been isolated. Among factors that influence this complexation process, molecular mass and ability to form micellar structures (supramolecules) of humic substances are of key importance.

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