Chalky soils

Ereids-bad, n. chalk bath, -boden, m. chalky soil, -fiotte, /. chalk liquor, -grund, m. chalk ground, -gur,/. agaric mineral (earthy calcium carbonate). 

Montmorillonite clays absorb water readily, swell greatly and confer highly plastic properties to a soil. Thus soil stress (Section 14.8) occurs most frequently in these soils and less commonly in predominantly kaolinitic types. Similarly, a soil high in bentonite will show more aggressive corrosion than a soil with a comparable percentage of kaolinite. A chalky soil usually shows low corrosion rates. Clay mineralogy and the relation of clays to corrosion deserves attention from corrosion engineers. Many important relationships are not fully understood and there is need for extensive research in this area. 

Poor maintenance of topsoil is also a major concern. Synthetic fertilizers have no organic bulk and do not provide a food source for soil microorganisms and earthworms. Over time, a soil treated with only these fertilizers loses biological activity, which diminishes the soil s fertility. Soils void of organic bulk become chalky and susceptible to wind erosion. Chalky soils lose their capacity to hold water, which means that more applied fertilizer is leached away. Ever-increasing amounts of fertilizer are thus needed. 

For the best crops, grow your raspberries in well-drained, well-fed (not chalky) soil, keep them well-mulched and watered and prune them at the right time of year. 

The disadvantages of using urea are that some urea evaporates especially if there is no rain within 4 days of application. It cannot be blended with phosphate nor potassium fertilisers, and it is less suitable on chalky soils. It can cause damage to seedlings. It does not work if the soil is too cold. 

Copper deficiency is a problem of peaty, very light sandy and thin organic chalky soils. Symptoms are most often seen in wheat and barley where it produces shrivelled leaf and ear tips. Chelated copper can be applied directly to crops or copper sulphate apphed to soils. 

Chalky or powdery Fine loose powder of calcium carbonate as a continuous body with little or no nodule development, consisting of micrite or microspar, with etched silicate grains, peloids and root and fungal-related microfeatures. Commonly is a transitional zone from calcareous soil to nodular horizons... 

Laminar Consists of sheets of laminated carbonate, in which the laminae are on a millimetre-scale. The term is synonymous with soilstone crust . Some forms are dark in colour. They commonly occur capping hardpan layers but can also occur within chalky layers or in the host sediment or soil. They can be interlayered with pisolitic calcretes on a centimetre-scale. Most are only a few centimetres thick but some forms can reach 2 m and can be... 

Coccolithophores are, with rare possible exceptions, exclusively marine algae, chiefly planktonic although some benthonic forms are known. They secrete minute calcitic plate scales a few microns across. The mineralized plate scales are called coccoliths and may be extremely abundant in some soil parent materials, particularly chalk. Chalk commonly consists almost exclusively of the tests of planktonic foraminifers, discussed below, and coccoliths the two components may be present in approximately equal-weight abundances, or either component may strongly predominate. Although both kinds of fossil are calcitic, they have remarkably different resistance to solution, and local conditions may favor concentration of one or the other type in soils derived from a chalky parent material. A characteristic Cretaceous coccolith is illustrated in Figure 5. 

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