Navigation

ชมรมดินปุ๋ยบนเว็บ

D.Andisols

Key to Suborders

DA. Andisols that have either:
1. A histic epipedon; or
2. In a layer above a densic, lithic, or paralithic contact or in a layer at a depth between 40 and 50 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallowest, aquic conditions for some time in normal years (or artificial drainage) and one or more of the following:
a. 2 percent or more redox concentrations; or
b. A color value, moist, of 4 or more and 50 percent or more chroma of 2 or less either in redox depletions on faces of peds or in the matrix if peds are absent; or
c. Enough active ferrous iron to give a positive reaction to alpha,alpha-dipyridyl at a time when the soil is not being irrigated. Aquands, p. 77

DB. Other Andisols that have, in normal years, a mean annual soil temperature of 0 oC or colder and a mean summer soil temperature that:
1. Is 8 oC or colder if there is no O horizon; or
2. Is 5 oC or colder if there is an O horizon. Gelands, p. 84

DC. Other Andisols that have a cryic soil temperature regime. Cryands, p. 81

DD. Other Andisols that have an aridic moisture regime. Torrands, p. 84

DE. Other Andisols that have a xeric moisture regime. Xerands, p. 95

DF. Other Andisols that have a 1500 kPa water retention of less than 15 percent on air-dried samples and less than 30 percent on undried samples throughout 60 percent or more of the thickness either:
1. Within 60 cm either of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower, if there is no densic, lithic, or paralithic contact, duripan, or petrocalcic horizon within that depth; or
2. Between either the mineral soil surface or the top of an organic layer with andic soil properties, whichever is shallower, and a densic, lithic, or paralithic contact, a duripan, or a petrocalcic horizon. Vitrands, p. 93

DG. Other Andisols that have an ustic moisture regime. Ustands, p. 92

DH. Other Andisols. Udands, p. 85

pages by <SoClaimon> sootin claimon : sootinc@gmail.com