Soil, characteristics texture

Basic soil characteristics, horizonation, texture, clay, air, water, solids, organic matter, organisms, and fundamental chemical concepts essential to soil chemistry... 

The three types of adsorption are (1) physical, (2) chemical, and (3) exchange adsorption. Especially important to the success of in situ treatment by Fe° are the soil characteristics, which affect soil sorptive behavior such as mineralogy, permeability, porosity texture, surface qualities, and pH. Physical adsorption is due to van der Waal s forces between molecules where the adsorbed molecule is not fixed on the solid surface but is free to move over the surface and may condense and form several superimposed layers. An important characteristic of physical adsorption is its reversibility. On the other hand, chemical adsorption is a result of much stronger forces with a layer forming, usually of one molecule thickness, where the molecules do not move. It is normally not reversible and must be removed by heat. The exchange adsorption and ion exchange process involves adsorption by electrical attraction between the adsorbate and the surface (Rulkens, 1998). 

Soil is also an important factor in the breakdown and movement of pesticides. Your local Soil Conservation Service can help determine the types of soil in your area and how they affect breakdown and movement. The three major soil characteristics that affect pesticides are texture, permeability, and organic matter. 

Key words soil texture, soil structure, soil characteristics, soil management, soil erosion. 

To promote the use of poor quality water for irrigation, a field research study was conducted in three semi-arid regions with water scarceness in Syria in order to define, under field conditions, the wheat yield response function to irrigation water salinity, the effect of soil texture and structural characteristics on the irrigation water salinity threshold, and to compare this value with the conventional threshold value. 

There was a discrepancy between water salinity limits for the three locations, which may be attributed to factors related to difference in soil texture and stmcture. This affects soil infiltration capacity and water retention. These soil hydrologic characteristics influence salt development in the soil profile, which affects plant... 

The size, and particularly the size distribution of the particles (or PSD, as particle size distribution is often abbreviated), which is closely related to the texture of the soil, is an important characteristic that determines many of the... 

Soils also display a wide range of physico-chemical characteristics that influence the bioavailability of toxic metals to microorganisms, fauna, and plant roots. These characteristics include soil texture, organic matter, cation and anion type, pH, or alkalinity. The presence of colloidal clay minerals in soils greatly increases the... 

Barium is not very mobile in most soil systems. The rate of transportation of barium in soil is dependent on the characteristics of the soil material. Soil properties that influence the transportation of barium to groundwater are cation exchange capacity and calcium carbonate (CaCO) content. In soil with a high cation exchange capacity (e.g., fine textured mineral soils or soils with high organic... 

The affinity of DOM with soil was very low with an average DOM sorption percentage of about 22.4 4.8% to 31.2 +5.2% only at an initial DOC concentration of 100 mg/1 and 200 mg/1, respectively, for the live selected DOMs (Table 10.3). This result was supported by the small slope m of 0.11 to 0.24 and Kd of 0.47 to 1.23 ml/g obtained from the IM isotherms. Liang et al. (1996), who worked on a variety of soils with clay contents ranging from 3 to 54%, showed that the adsorption of the DOC by soils increased as the clay, organic matter contents, and the surface areas of the soils increased. The coarse texture of the selected calcareous soil and the characteristics of the selected DOM itself can explain the lower affinity of DOM with soil observed in the present study. In addition, the acidic soil with higher Fe-oxide and Mn-oxide content exhibited much higher DOC adsorption ability than calcareous soil rich in 2 1 minerals. 

---