GEOG 106 Lecture Notes - Lecture 13: Chemical Process, Herbicide, Soil Horizon
Document Summary
Soil forming processes: solum as a chemical system: Solum is a highly active system of water, particles and organic matter as well as a dynamic chemical system. Four primary sources: bedrock, vegetation, runoff and atmosphere. Bedrock: large amounts of weathered material to the solum. Vegetation is also an important source of soil minerals, including phosphorous, nitrogen, carbon, calcium, and many other elements. Nitrogen fixing plants: facilitate the transfer of nitrogen from air to soil increases soil fertility. Chemical ions are atoms or groups of atoms that carry electrical charges that facilitate bonding with other ions or with minute clay particles. Soils chemical system depends on amount of ions, the availability of water, the soil temperature and the soil composition. Ions are subject to three fundamental processes in the soil: They may be taken up by plants. They may be moved (translocated) with soil water to other locations in the soil, including being washed from the solum into groundwater at depth.
