Clay soils management

Potassium is determined in the acetic acid as well as the lactic acid extract. The potassium values for biologically managed fields lie between 100 and 200 mg K kg soil, and are less than those recommended for conventional agriculture. Light soils normally have low values, and clay soils, which bind more potassium, have higher K levels. Potash fixation is also assessed according to Schlichting and Blume (1951, p. 84). 

Ghadiri, H., Rose, C.W., 2001. Degradation of endosulfan in a clay soil from cotton farms of western Queensland. J. Environ. Manag. 62, 155-169. 

Armstrong AC, Matthews AM, Portwood AM, Leeds-Harrison PB, Jarvis NJ. CRACK-NP A pesticide leaching model for cracking clay soils. Agr Water Manage 2000 44 183-99. 

Weng CH, Yuan C, Tu HH. (2003). Removal of trichoroethylene from clay soil by series-electrokinetic process. Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management 7(l) 25-30. 

Soil management involves maintaining such properties as workability, drainage and root growth, which are functions of porosity and permeability. The type and amount of clay minerals in a soil also influence, through their surface properties. 

As an example, grease is an amalgam of both low and high volatility components. The former can be base oils, glycerol, rosin oil, mineral oil, and the like. The latter can be low volatility soaps such as stearates, but also non-volatile materials such as clays, tars, metal particulate, and Teflon. Certainly this mixture will fractionate when mixed with solvent in a flash drum or a distillation column — and become a challenge to soil management. 

Brinkman R. 1985. Mineralogy and surface properties of the clay fraction affecting soil behaviour and management. In Soil Physics and Rice. Manila International Rice Research Institute, 161-182. 

Over millions of years, rocks are weathered down into small particles, which form the basic ingredient of almost all soil. The size and chemical composition of the particles depends on the rock they came from—that is, the physical location and geological profile of your area—and determines the type of soil you have. There are three types of weathered rock particles that make up soil sand, silt, and clay. The proportion of the different particles found In a soil determines Its type—what name it is given—and how it behaves and should be managed. Most soil contains a mixture of all... 

More generally, Walter et al. (2002) tested the spatial cross-correlation between weed species and several soil properties. Certain weeds were correlated with specific soil chemical properties (e.g. P, pH) however, other species did not show consistent correlation with soil types between fields and sampling times, and some were correlated with more than one soil property. The most consistent relationship was between weed density and clay content. This result suggests that weeds have different resource requirements and that modifying soil conditions to manage certain weeds may promote others. 

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