CRITICAL MOISTURE CONTENT OF COMPACTED AGRICULTURAL SOILS WITH VARYING ORGANIC MATTER CONTENT

2013 ◽  
Author(s):  
Prof. John O Ohu ◽  
Prof. Eli E Mamman ◽  
Abubakar A Mustapha
Keyword(s):  
Organic Matter ◽  
Moisture Content ◽  
Agricultural Soils ◽  
Organic Matter Content ◽  
Matter Content ◽  
Critical Moisture Content ◽  
Critical Moisture

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 REED OVERGROWTH UTILISATION

2001 ◽  
Vol 1 ◽  
pp. 54
Author(s):  
Ēriks Kronbergs ◽  
Imants Plūme ◽  
Aivars Kaķītis
Keyword(s):  
Organic Matter ◽  
Moisture Content ◽  
Specific Energy ◽  
Organic Matter Content ◽  
Matter Content ◽  
Effluent Treatment ◽  
Deep Layers

The rootfelt properties are investigated for development of technologies for Lake’s overgrowth removal and utilisation. The specific energy of disintegration of rootfelt vary from 7,3 to 18,1 kJ/m2 in dependence on methods used for overgrowth partition. The minimal density of rootfelt is 220 kg/m3 at a surface and the density increases to 1050 kg/m3 in deep layers o f overgrowth. The moisture content (dry basis) of rootfelt vary from 800 % to 250 % and organic matter content lower from 96 % to 25 % in dependence on depth and location of rootfelt in watercourse. The suitable methods and technologies are elaborated for rootfelt removal and biomass utilisation for litter, compost production or for production of Constructed Reedbeds for Effluent Treatment.

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.

scholarly journals Influence of Organic Matter Content on Engineering Properties of Clays

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yue Gui ◽  
Qiumin Zhang ◽  
Xiaqiang Qin ◽  
Jianfei Wang
Keyword(s):  
Organic Matter ◽  
Shear Strength ◽  
Moisture Content ◽  
Void Ratio ◽  
Clay Soil ◽  
Organic Matter Content ◽  
Friction Angle ◽  
Matter Content ◽  
Atterberg Limit ◽  
Shear Characteristics

Most natural sedimentary clay contains organic matter, and even a small amount of organic matter will have a great impact on the physical and mechanical properties of clay. In order to clarify the influence of organic matter content on clay soil, the illite-quartz mixture was mixed with natural amorphous peat soil (organic matter content is 50%) in different proportions for studying the influence of different organic matter contents on the physical properties (specific gravity, Gs; moisture content, w ; void ratio, e; liquid limit, w L ; plastic limit, w p ; plasticity index, Ip) and shear characteristics (cohesion, c; friction angle, φ) of clay soil. The experimental results found that, with the change of organic matter content, the specific gravity and void ratio of clay changed linearly, while the water content, Atterberg limit, shear strength, cohesion, and friction angle changed nonlinearly with the increase of organic matter content. Moisture content and Atterberg limit have a turning point when OC = 7.5%. Shear strength, cohesion, and friction angle all have obvious turning points when OC = 7.5% and OC = 37.5%. The variation of moisture content and Atterberg limit with organic matter content indicates that OC = 7.5% may be the limit value for the different forms of organic matter in the clay. When OC ≤ 7.5%, the organic matter in clay is in the bound state; when OC > 7.5%, the bound organic matter reaches saturation; and the free organic matter gradually increases. The change law of shear strength characteristics with organic matter content shows that the interaction between minerals and organic matter exhibits different shear characteristics under different organic matter content. When OC ≤ 7.5%, clay shows mineral properties, when 7.5% < OC ≤ 37.5%, clay shows mineral-free organic matter properties, and when OC > 37.5%, clay shows free organic matter properties.

scholarly journals The use of the 'wet workability limit' to predict the land quality 'workability' for some Uruguayan soils.

1988 ◽  
Vol 36 (1) ◽  
pp. 91-103
Author(s):  
A. Terzaghi ◽  
W.B. Hoogmoed ◽  
R. Miedema
Keyword(s):  
Organic Matter ◽  
Moisture Content ◽  
Linear Relationship ◽  
Critical Point ◽  
Laboratory Methods ◽  
Land Quality ◽  
Critical Moisture Content ◽  
Critical Moisture ◽  
Highly Correlated

In an attempt to predict soil workability, the upper critical moisture content for tillage was determined for some Uruguayan soils, using two laboratory methods developed for Dutch conditions ('upper tillage limit' or UTL, and 'wet workability limit' or WWL). The results obtained showed that the critical point is mainly influenced by the percentage clay and organic matter (OM) in the soil, yielding the linear relationship: UTL = 7.5 + 1.91 x OM (%) + 0.34 x clay (%). The UTL is highly correlated with the moisture content at a range of pF values between 2.0 and 2.7, this being a consequence of the influence of clay and organic matter on the shape of the pF curve. The results obtained by both methods (UTL and WWL) are highly correlated (r = 0.88). Within a certain range of texture, both methods give statistically the same result. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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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