ACCT 2220 Study Guide - Final Guide: Manganese, Water Content, Ferrous

• School: University of Guelph
• Department: Accounting
• Course: ACCT 2220
• Professor: Adeel Mahmood

Document Summary

Mottles are patches or blotches of red/brown in a general matrix of light brown or grey soil. This mottling indicates the soil is wet most of the time with some better aerated locations. Dark colour of a surface soil layer reflects the accumulation of organic matter from the decay of plant material. This represents iron that is in the oxidized or ferric state (fe+++) In soil, iron will be oxidized when the soil is well aerated (important for plant growth) Soils with a dull blue-gray colour (reduced or ferrous iron fe++) indicates poorly aerated soil conditions, usually because the soil is saturated with water most of the time. Three major factors influence soil colors: organic matter content, water content, presence and oxidation states of iron and manganese oxides. Organic matter tends to coat mineral particles, darkening and masking the brighter colors of the minerals themselves. Water content has a more profound indirect effect on soil colors.