Structural stability, pore size distribution and surface charge properties of clay soils with varying mineralogy and organic matter content.

1969 ◽  
Vol 77 (1-2) ◽  
pp. 11-31
Author(s):  
Víctor A. Snyder ◽  
Rafael Pietri Oms ◽  
Milagros Miró ◽  
Héctor M. Lugo
Keyword(s):  
Organic Matter ◽  
Pore Size ◽  
Organic Matter Content ◽  
Clay Mineralogy ◽  
Matter Content ◽  
Clay Soils ◽  
Size Distributions ◽  
Moisture Retention ◽  
Variable Charge ◽  
Pore Size Distributions

This study evaluated interactive effects of mineralogy and organic matter content on chemical and physical properties of clay soils. Measurements were taken at different depths in four soil profiles characterized by oxidic, kaolinitic, mixed and montmorillonitic clay mineralogies, respectively. Within a given profile, organic carbon content varied more or less continuously with depth, whereas texture and mineralogy remained relatively constant. Thus in this study the combined effects of organic matter content and clay mineralogy could be evaluated in various combinations while texture remained constant. Resistance of soil aggregates to slaking by water was related primarily to soil organic matter content, with relatively minor differences attributable to mineralogy except in the oxidic soil where oxides seemed to exert an important stabilizing effect. Organic matter was associated with an increase in water-holding capacity both in the interaggregate pore space (0 to -0.33 bar moisture retention range) and intraaggregate porosity (-0.33 to -0.8 bar retention range). The enhancing effect of organic matter on intra-aggregate porosity seemed most prominent in the soils with oxidic and kaolinitic mineralogies, suggesting the importance of organic matter for maximizing plant-available water retention in these soils. For all soils and depths, pore-size distributions within the 0 to -0.33 bar moisture retention range were log-normally distributed, with the geometric mean pore diameter and log standard deviation practically constant. These results implied that although the total 0 to -0.33 bar porosity varied strongly (primarily with organic matter content), the relative pore size distributions were all similar. In agreement with other studies in the literature, effective cation exchange capacity (ECEC) increased and the zero point of charge (ZPC) of the variable charge complex decreased as organic matter increased, and as clay mineralogy varied in the order oxidic -> kaofinitic -> mixed -> montmorillonitic. Results of this study highlight the importance of managing organic matter for optimizing physical and chemical properties in soils, particularly those dominated by variable charge minerals.

scholarly journals Effectivity of bulrush (Scirpus californicus.) as a soil conditioner in increasing sandy and clay soil fertility

2021 ◽  
Vol 22 (8) ◽  
Author(s):  
Munifatul Izzati ◽  
SRI HARYANTI ◽  
RINI BUDI HASTUTI
Keyword(s):  
Organic Matter ◽  
Soil Fertility ◽  
Water Retention ◽  
Clay Soil ◽  
Organic Matter Content ◽  
Matter Content ◽  
Clay Soils ◽  
Soil Conditioner ◽  
Soil P ◽  
Scirpus Californicus

Abstract. Izzati M, Haryanti S, Hastuti RB. 2021. Effectivity of bulrush (Scirpus californicus) as a soil conditioner  increasing sandy and clay soil fertility. Biodiversitas 22: 3423-3429. Bullrush (Scirpus californicus) is a species of macrophytes that often populates lakesides. This aquatic plant was rarely studied and its use has not been explored yet. This study was carried out to determine the effects of soil conditioner made from bulrush on sandy and clay soil fertility. Collected bulrush from Rawa Pening lake was milled into a powder and used as a soil conditioner in a proportion of 1:1. After a week, soil fertility was evaluated including organic matter content, water retention, the ratio of C/N, and bacteria population. The study was designed using a Completely Randomized Design with two treatments and control. Resulted data were analyzed using a t-test to evaluate the difference between the two treatments. Results showed that bulrush powder application significantly increased sandy and clay soil fertility. The organic matter content significantly increased in both sandy (p<0,01) and clay soils (p<005). The water retention of sandy soil was increased by 74% (p<0,01), while in clay soil was reduced by 27% (p<0,01). The C/N ratio was significantly reduced in both sandy and clay soil (p<0,05), while the bacteria population significantly increased (p<0,01). It is suggested to use the bulrush as a soil conditioner particularly for sandy and clay soils.

Persistence and Movement of Perfluidone in Soil

Weed Science ◽  
1975 ◽  
Vol 23 (5) ◽  
pp. 344-348 ◽  
Author(s):  
M. L. Ketchersid ◽  
M. G. Merkle
Keyword(s):  
Organic Matter ◽  
Ultraviolet Irradiation ◽  
Organic Matter Content ◽  
Field Capacity ◽  
Matter Content ◽  
Loamy Sand ◽  
Clay Soils ◽  
Alkaline Soils ◽  
Downward Movement ◽  
Petri Dishes

Perfluidone (1,1,1-trifluoro-N-[2-methyl-4-(phenylsulfonyl)phenyl]-methanesulfonamide) was chemically stable for 2 to 3 weeks on the surface of three Texas soils either air dry or at field capacity and at temperatures of 22 and 46 C. Perfluidone was susceptible to photodecomposition when applied to glass petri dishes and exposed to ultraviolet irradiation. Perfluidone was readily leached through neutral or slightly alkaline soils, with a tendency toward greater downward movement in soils having low clay and organic matter content. However, leaching was less in an acid loamy sand than in either neutral loamy sand or clay soils.

Relationship between pore size distributions and physical properties of clay soils

Soil Research ◽  
1974 ◽  
Vol 12 (2) ◽  
pp. 107 ◽  
Author(s):  
ID Sills ◽  
LAG Aylmore ◽  
JP Quirk
Keyword(s):  
Particle Size ◽  
Pore Size ◽  
Pore Volume ◽  
Total Pore Volume ◽  
Particle Size Analysis ◽  
The Other ◽  
Clay Soils ◽  
Size Analysis ◽  
Size Distributions ◽  
Pore Size Distributions

Pore size distributions using mercury injection and nitrogen sorption techniques were determined on a number of soils classified as clays on the basis of particle size analysis. Some of these soils exhibit markedly different consistencies during texturing and undergo changes in texture during prolonged manipulation, e.g. subplastic, superplastic and self-mulching soils. The pore size distributions for these soils do not differ significantly from those obtained for the normal labile clay soil in the pore size range 2 nm to 50 �m. The clay soils examined, with the exception of the krasnozem, have the majority of their pore volume within pores smaller than 10 nm with the predominant pore size centred around 3 nm plate separation. In the case of the krasnozem, the particle size analysis does not correspond to the texture assessment as a clay loam. Surface and subsoil samples of the krasnozem have high porosities and predominant plate separations of 6 nm. They consequently possess significantly different pore size distributions from the other clays. In the case of the surface sample, only a small proportion of its total pore volume is in pores smaller than 10 nm. These differences in pore structure observed between the krasnozem and the other soils examined may result from differences in mineralogy, and in particular from the high sesquioxide content of the krasnozem.

Effect of air-drying and critical point drying on the porosity of clay soils

1984 ◽  
Vol 21 (1) ◽  
pp. 181-185 ◽  
Author(s):  
C. R. De Kimpe
Keyword(s):  
Organic Matter ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Critical Point ◽  
Size Distribution ◽  
Pore Volume ◽  
Organic Matter Content ◽  
Total Pore Volume ◽  
Clay Soils ◽  
Critical Point Drying

Samples from four surface and one subsurface horizons of clay-rich soils from Quebec were air-dried and critical point dried. In the latter samples, the total pore volume was 19–84% larger than in the former samples. The total pore volume, determined by mercury intrusion porosimetry and density measurements, was subdivided into large (> 8.8 μm), medium, and small (< 0.19 μm) pores. The effect of drying on these pores was estimated. Medium-sized pores were affected most by the drying technique, followed next by the large pores, and finally by the small pores. The modifications due to drying could not be explained adequately by shrinkage and it was assumed, from the pore-size distribution curves, that organic matter content had a buffer effect on particle reorganization. Keywords: critical point drying, clay soils, pore volume, pore-size distribution, organic matter.

Influence of organic matter and phosphate content on the point of zero charge of variable charge components in oxidic soils

Soil Research ◽  
1985 ◽  
Vol 23 (4) ◽  
pp. 643 ◽  
Author(s):  
GP Gillman
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Matter Content ◽  
Parent Material ◽  
Point Of Zero Charge ◽  
Average Amount ◽  
Ph Values ◽  
Variable Charge ◽  
Zero Charge ◽  
Extractable Phosphorus

The point of zero charge of the variable charge components (pH,) of oxidic soils formed on basaltic parent material in humid tropical Queensland has been measured on samples from virgin rainforest and cultivated fertilized fields. The average amount of free iron in these soils is about 10%. Soils with low organic matter content and low extractable phosphorus have high pH, values. Regression analysis showed pH, to be reduced by about one pH unit for each 1% increase in organic carbon or for each 100 �g/g increase in extractable phosphorus. Implications with respect to cation and anion exchange capacities are briefly discussed.

scholarly journals Organic Matter Preservation in Ancient Soils of Earth and Mars

Life ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 113
Author(s):  
Adrian P. Broz
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Organic Matter Content ◽  
Clay Mineralogy ◽  
Matter Content ◽  
Published Data ◽  
Original Research ◽  
Forming Process ◽  
Soil Science Society ◽  
Diagenetic Alteration

The emerging field of astropedology is the study of ancient soils on Earth and other planetary bodies. Examination of the complex factors that control the preservation of organic matter and other biosignatures in ancient soils is a high priority for current and future missions to Mars. Though previously defined by biological activity, an updated definition of soil as planetary surfaces altered in place by biological, chemical or physical processes was adopted in 2017 by the Soil Science Society of America in response to mounting evidence of pedogenic-like features on Mars. Ancient (4.1–3.7 billion year old [Byr]) phyllosilicate-rich surface environments on Mars show evidence of sustained subaerial weathering of sediments with liquid water at circumneutral pH, which is a soil-forming process. The accumulation of buried, fossilized soils, or paleosols, has been widely observed on Earth, and recent investigations suggest paleosol-like features may be widespread across the surface of Mars. However, the complex array of preservation and degradation factors controlling the fate of biosignatures in paleosols remains unexplored. This paper identifies the dominant factors contributing to the preservation and degradation of organic carbon in paleosols through the geological record on Earth, and offers suggestions for prioritizing locations for in situ biosignature detection and Mars Sample Return across a diverse array of potential paleosols and paleoenvironments of early Mars. A compilation of previously published data and original research spanning a diverse suite of paleosols from the Pleistocene (1 Myr) to the Archean (3.7 Byr) show that redox state is the predominant control for the organic matter content of paleosols. Most notably, the chemically reduced surface horizons (layers) of Archean (2.3 Byr) paleosols have organic matter concentrations ranging from 0.014–0.25%. However, clay mineralogy, amorphous phase abundance, diagenetic alteration and sulfur content are all significant factors that influence the preservation of organic carbon. The surface layers of paleosols that formed under chemically reducing conditions with high amounts of iron/magnesium smectites and amorphous colloids should be considered high priority locations for biosignature investigation within subaerial paleoenvironments on Mars.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

Physico-Chemical Properties of Soil Collected from Chandrabhaga River in Kalmeshwar, Nagpur, Maharashtra

2020 ◽  
Vol 07 (02) ◽  
pp. 1-3
Author(s):  
Amita M Watkar ◽  
Keyword(s):  
Organic Matter ◽  
Soil Quality ◽  
Agricultural Land ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Matter Content ◽  
Soil Attributes ◽  
Essential Components ◽  
Agricultural Land Management ◽  
Physical And Chemical

Soil, itself means Soul of Infinite Life. Soil is the naturally occurring unconsolidated or loose covering on the earth’s surface. Physical properties depend upon the amount, size, shape, arrangement, and mineral composition of soil particles. It also depends on the organic matter content and pore spaces. Chemical properties depend on the Inorganic and organic matter present in the soil. Soils are the essential components of the environment and foundation resources for nearly all types of land use, besides being the most important component of sustainable agriculture. Therefore, assessment of soil quality and its direction of change with time is an ideal and primary indicator of sustainable agricultural land management. Soil quality indicators refer to measurable soil attributes that influence the capacity of a soil to function, within the limits imposed by the ecosystem, to preserve biological productivity and environmental quality and promote plant, animal and human health. The present study is to assess these soil attributes such as physical and chemical properties season-wise.

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