(par 2.2.1. 6.5) Soil Formation & Soil Horizons
http://nerrs.noaa.gov/doc/siteprofile/acebasin/html/envicond/soil/slform.htm A number of conceptual models of soil formation have been postulated over the years. The two that have been key in our basic understanding of soils and soil formation are those of Hans Jenny (1941) and Roy W. Simonson (1959). Five Factors of Soil Formation Jenny (1941) addressed the question of which environmental factors are […]
(par 2.2.1. 6.2) Why Are Earthworms Important?
http://www.earthwormsoc.org.uk/earthworm-information/earthworm-information-page-3 Soil structure Earthworms have been called ‘ecosystem engineers’. Much like human engineers, earthworms change the structure of their environments. Different types of earthworms can make both horizontal and vertical burrows, some of which can be very deep in soils. These burrows create pores through which oxygen and water can enter and carbon dioxide can […]
(par 2.2.1. 6.4) Soil Properties
http://broome.soil.ncsu.edu/ssc012/Lecture/topic8.htm Physical Properties Features of the soil profile and the soil horizons are often described in the field in terms of the soil’s physical properties. Horizons are defined based on difference in the physical properties. Horizons differ from horizons above and below by some physical property. Soil physical properties affect the appearance and feel of […]