Introduction to Soil Chemistry

peds 13
Figure 1.7. Peds isolated form soil. From top to bottom spheroidal, platelike, blocklike, and
prismlike.
Organic matter coatings are common in acid sandy soils, especially those called
Spodosols.
Coating of primary and secondary soil structures is an extremely important
phenomenon for the analysis of soil. Without coating the chemical activity of
soil primary and secondary particles could be determined by knowledge of
their structure and makeup. With coating the chemistry becomes vastly more
complex. This complexity will be discussed in later chapters.
For the soil separates (sand, silt, clay) to become aggregated, they must
come close together. The forces that cause particles to come together are the
weight of overlying soil, plant roots moving through the soil, heating and