Relating Magnetic Susceptibility and Organic Matter Content in Agricultural Soils

2013 ◽  
Author(s):  
D. Bugheanu ◽  
C. Iacob
Keyword(s):  
Magnetic Susceptibility ◽  
Organic Matter ◽  
Agricultural Soils ◽  
Organic Matter Content ◽  
Matter Content

Plastic limits of agricultural soils as functions of soil texture and organic matter content

Soil Research ◽  
2012 ◽  
Vol 50 (1) ◽  
pp. 7 ◽  
Author(s):  
Thomas Keller ◽  
Anthony R. Dexter
Keyword(s):  
Organic Matter ◽  
Soil Texture ◽  
Agricultural Soils ◽  
Organic Matter Content ◽  
Clay Content ◽  
Liquid Limit ◽  
Matter Content ◽  
Pedotransfer Functions ◽  
Strongly Correlated ◽  
Yield Information

The plastic limits (lower plastic limit, PL; and liquid limit, LL) are important soil properties that can yield information on soil mechanical behaviour. The objective of this paper is to study the plastic limits of agricultural soils as functions of soil texture and organic matter (OM) content. The plastic limits were highly related to the clay content. The LL was more strongly correlated with clay than was PL, but the reasons are unclear. Interestingly, PL was virtually unaffected by clay content for soils with clay contents below ~35%. The OM had a strong effect on the plastic limits. This effect was clearly demonstrated when analysing soils of similar texture with a range of OM. We present equations (pedotransfer functions) for estimation of PL, LL, and plasticity index (PI) from soil texture and OM. Finally, we predict that the clay content must be ≥10% for soils without OM to be plastic; however, soils with <10% clay can be plastic if OM is present. More research is needed to investigate OM effects on soil consistency.

scholarly journals Adsorption and Desorption Behavior of Herbicide Mefenpyr-diethyl in the Agricultural Soils of Morocco

2018 ◽  
Vol 7 (5) ◽  
pp. 386-395 ◽  
Author(s):  
Abdellah El Boukili ◽  
Nidae Loudiyi ◽  
Ahmed El Bazaoui ◽  
Abderrahim El Hourch ◽  
M'Hamed Taibi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Adsorption Capacity ◽  
Agricultural Soils ◽  
Organic Matter Content ◽  
Matter Content ◽  
Isotherm Models ◽  
Desorption Process ◽  
Adsorption And Desorption ◽  
Total Percentage ◽  
Adsorption Isotherm Models

The present study was conducted in order to investigate the adsorption and desorption behavior of Mefenpyr-diethyl (MFD) using the batch equilibration technique in four soils, with different ranges of organic matter content, from different regions of Morocco orders of Benimellal (Soil 1), Settat (Soil 2), Sidi Bettach (Soil 3) and EL Hajeb (Soil 4). The adsorption isotherm models Langmuir, linear and Freundlich were used to compare the adsorption capacity of the soils. The results indicated that the Freundlich equation provided the best fit for all adsorption data. The values of KF and Kd ranged from 4.45 to 15.9 and 4.30 to 18.30 L.kg-1 , respectively. The calculated total percentage of desorption values from the Soil 1, Soil 2, Soil 3 and Soil 4 after the four desorption process were 59 %; 55,6 %; 37,5 % and 52,5%, respectively. Highest adsorption and desorption were observed in soil 1, and the lowest was in soil 3. According to the adsorption and desorption results, organic matter and clay seemed to be the most important factors influencing the adsorption capacity of MFD.

scholarly journals Sorption Behavior of Lead (Pb) onto Agricultural Soils of Khyber Pakhtunkhwa, ‎Pakistan: Potentials for Leaching

2021 ◽  
Author(s):  
Iqbal Ahmad ◽  
Bushra Khan ◽  
Nida Gul ◽  
Muhammad Khan ◽  
Javaid Iqbal ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Texture ◽  
Agricultural Soils ◽  
Organic Matter Content ◽  
Sorption Isotherms ◽  
Matter Content ◽  
Sorption Behavior ◽  
Silty Clay ◽  
Clay Loam

Abstract Lead (Pb) contamination in soil and subsequent transport in groundwater poses severe threats to the food safety and human health. In current study, the effects of soil organic matter on sorption behavior of Pb onto six agricultural soils were investigated by batch sorption experiments and microscopic characterization. Results indicated that Pb sorption onto agricultural soils was dominated by the soil organic matter content and soil texture. The decrease of organic matter content reduced the sorption capacity of Pb onto agricultural soils. Based on soil texture, the Pb sorption was highest in clay soil and lowest in silt type of soil. The overall Pb sorption was in the order of clay > clay loam > silty clay loam ≈ loam > silt loam > silt. The sorption isotherms of measured aqueous and soil phase Pb concentrations were fit well with the linear sorption model. The organic carbon normalized partition coefficients (Log KOC) ranged from 2.90 to 2.99. Linear partition coefficient (Kd) values were positively correlated with the soil properties, such as clay (R2 =0.90), OC (R2 =0.94) and pH (R2 = 0.45); however, weak correlation was found between Kd and soil sand contents (R2 = 0.12). The leachability model showed potential risk of Pb leaching from silt soil with lowest organic matter content. The findings are of significant importance for understanding potential threats of Pb to the soil ecosystem, groundwater, plants, and humans.

scholarly journals Adsorption and Degradation Behavior of Six Herbicides in Different Agricultural Soils.

2021 ◽  
Author(s):  
Umrbek Sharipov ◽  
Martin Kočárek ◽  
Miroslav Jursík ◽  
Antonín Nikodem ◽  
Luboš Borůvka
Keyword(s):  
Organic Matter ◽  
Agricultural Soils ◽  
Negative Relationship ◽  
Organic Matter Content ◽  
Exchange Capacity ◽  
Matter Content ◽  
Sorption Coefficient ◽  
The Czech Republic ◽  
Degradation Rates ◽  
Agricultural Regions

Abstract This study focuses on the assessment of herbicide adsorption and degradation in three soils (Haplic Chernozem, Haplic Fluvisol, and Arenic Regozem) from different agricultural regions of the Czech Republic where sunflower is cultivated. Soil samples were used in laboratory batch sorption and degradation experiments for six herbicides commonly used on sunflower crops. The findings are used to examine the effect of soil and herbicide properties on adsorption and degradation, as well as to determine the possible relation between the two processes. The (Kf) sorption coefficient ranged from 1.07 to 135.37 cm3/n μg1-1/n g-1, and sorption increased in order: dimethenamid-p < pethoxamid < s-metolachlor < flurochloridone < aclonifen < pendimethalin. Sorption of all six herbicides was positively correlated with organic matter content (p < 0. 001), and cation exchange capacity (p < 0.001). pH was negatively correlated with the sorption of all six compounds (p < 0.001). Degradation rates of herbicides ranged from 0. 012 to 0. 048 day-1, which corresponding to (DT50) half-lives between 14 - 57 days respectively. The longer half-lives were always found in Haplic Fluvisol with higher organic matter content. Results showed that both adsorption and degradation of herbicides is mainly controlled by soil organic matter. A negative relationship was found between the sorption coefficient and the rate of degradation. It can be concluded that the Freundlich sorption coefficient (Kf) can be a good predictor for soil degradation of the studied herbicides.

The Holocene paleoenvironmental history of Western Caucasus (Russia) reconstructed by multi-proxy analysis of the continuous sediment sequence from Lake Khuko

The Holocene ◽  
2020 ◽  
pp. 095968362097278
Author(s):  
Alexei M Grachev ◽  
Elena Y Novenko ◽  
Evgeniy A Grabenko ◽  
Mikhail Y Alexandrin ◽  
Elya P Zazovskaya ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnetic Susceptibility ◽  
Organic Matter ◽  
Sediment Core ◽  
Organic Matter Content ◽  
Matter Content ◽  
Western Caucasus ◽  
Climate History ◽  
The Holocene ◽  
The Western Caucasus

This paper presents new multi-proxy records of the Holocene environmental and climatic changes in the Western Caucasus revealed from a continuous sediment sequence from mountainous Lake Khuko (Caucasus State Natural Biospheric Reserve, 1744 m a.s.l.). Palaeoecological analyses of a sediment core for grain size, magnetic susceptibility, loss on ignition, and pollen allowed us to determine five principal climatic phases with several subphases since 10.5 ka BP. The age model is based on seven accelerator mass spectrometry 14C dates, supplemented by 210Pb data for the uppermost part of the sediment core. Warm periods (10.5–6.7, 6.7–5.5, 3.5–2.4, 0.8–0.5 ka BP) were characterized by high biological productivity in the lake as indicated by high organic matter content and expansion of forests, typical of modern low and middle mountain zones, as indicated by the increase in abundance of Quercus, Ulmus, Corylus, and Tilia in the pollen assemblages. Cold periods (5.5–3.5, 2.4–0.8, and 0.5 ka BP–present) are marked by a consistent decrease in organic matter content in lake deposits and possibly higher intensity of the catchment erosion. The changes in pollen assemblages (for instance peaks of Abies, Picea, and Pinus) suggested a potential elevational decline in the boundaries of vegetation belts and expansion of high-altitude woodlands. Abrupt changes in the lake ecosystem were identified between 4.2 and 3.5 ka cal BP marked by a short-term variation in sediment regime shown by variation in organic matter content, magnetic susceptibility values, and sediment grain size. This was probably caused by climatic fluctuations in the Western Caucasus region as a result of complex shifts in the ocean-atmosphere system during the 4.2 ka event. Overall, the first Holocene multi-proxy continuous lake sediment record provides new insights into the climate history in the Western Caucasus.

scholarly journals Pedological characteristics of soils in the watersheds of Oueds Nekôr and Ghiss (Central Rif; Morocco)

2021 ◽  
Vol 298 ◽  
pp. 04002
Author(s):  
Soukaina Ed Dakiri ◽  
Hatim Faiz ◽  
Jaouad Ouldchaib ◽  
Said El Moussaoui ◽  
Hajar El Talibi ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Organic Matter ◽  
Organic Matter Content ◽  
Matter Content ◽  
Alkaline Soils ◽  
Sparse Vegetation ◽  
Physico Chemical ◽  
Poorly Differentiated ◽  
Well Differentiated ◽  
Steep Slopes

The objective of this work is the pedological characterization of soils in the watersheds of Oueds Nekôr and Ghiss. Several profiles were identified and sampled for Physico-chemical and sedimentological analyses (color index, magnetic susceptibility, pH, granulometry, water content, organic matter, and carbonates). The watersheds in question are roughly characterized by a soft and diversified lithology, a sparse vegetation cover, and a semi-arid Mediterranean climate. The soils in the Oued Nekôr watershed are of the silty type (> 50%), not very developed and relatively well-drained, and become well-drained stony in the steep and eroded areas. Soil pH varies between 7 and 8, reflecting low alkaline to alkaline soils. In the Oued Ghiss watershed, the sandstone-limestone or marl-schist soils are poorly differentiated in the steep slopes. The well-drained soils are gravelly, relatively alkaline, and show the beginning of rubefaction. Very locally on wooded flats, the soil profiles can become deep and well-differentiated due to colluvial accumulation. The dark brown eluvial A horizon is relatively rich in organic matter (3.6%). The well individualized illuvial B horizon has strongly rubbed concretions and is richer in organic matter (4.6%). The light beige C horizon corresponds to the strongly altered marl and limestone parent rock with low organic matter content (1.3%) and very low magnetic susceptibility values.

scholarly journals The relationship between soil properties, enzyme activity and land use

2017 ◽  
Vol 78 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Ewa Błońska ◽  
Jarosław Lasota ◽  
Maciej Zwydak
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Enzyme Activity ◽  
Soil Properties ◽  
Agricultural Soils ◽  
Vegetation Type ◽  
Organic Matter Content ◽  
Matter Content ◽  
Carbon And Nitrogen ◽  
The Relationship

Abstract The aim of this study was to assess the effects of different types of land use (forest, tillage and pasture) on soil properties, especially enzyme activity. Our investigation was carried out on 53 research plots with 11 plots in broadleaved forest stands, 12 plots in mixed broadleaved stands, 10 plots in mixed coniferous stands, 9 plots on tillage and 11 plots on pasture. The soil samples were collected from a depth of 0–15 cm after removing the organic horizon. Contents of organic carbon and nitrogen, pH and soil texture were investigated. Furthermore, dehydrogenase and urease activity were determined. Significant differences in the enzyme activity between forest and agricultural soils were observed, thus demonstrating that enzyme activity is influenced by the organic matter content of the soil. The highest enzyme activity was recorded in the forest soil within broadleaved stands, whilst the lowest activity was found in tillage soil, because tillage soil contained significantly less organic matter. High enzymatic activity of pasture soils is the combined result of vegetation type and the lack of plowing.

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