FORESTRY
SOIL SCIENCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Clay
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Silt
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Sand
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Loam
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Detailed explanation-1: -Clay has a great capacity to attract and hold cations because of its chemical structure. However, CEC varies according to the type of clay. It is highest in montmorillonite clay, found in chocolate soils and black puggy alluvials.
Detailed explanation-2: -Soil clay minerals and organic matter tend to be negatively charged, thus attracting positively charged ions (cations) on their surfaces by electrostatic forces. As a result, the cations remain within the soil root zone and are not easily lost through leaching.
Detailed explanation-3: -Sandy soils low in organic matter have a very low CEC (less than 3 cmolc/kg) while heavier clay soils or soils high in organic matter generally have a much higher CEC (greater than 20 cmolc/kg).