Ustox

Ustox

[′üst‚äks]
(geology)
A suborder of the soil order Oxisol that is low to moderate in organic matter, well drained, and dry for at least 90 cumulative days each year.
References in periodicals archive ?
The soil is classified as Oxisol Ustox Eutrustox [7] of clayey texture (554.80 g/kg clay, 359.08 g/kg silt and 58.82 g/kg sand) and presented the following chemical characteristics: pH (Ca[Cl.sub.2]) 5.24, P (Mehlich) 33.72 mg/[dm.sup.3], K (Mehlich) 0.11 cmolc/[dm.sup.3], [Ca.sup.2+] (KCl 1 mol/L) 5.88 cmolc/[dm.sup.3], [Mg.sup.2+] (KCl 1 mol/L) 1.91 cmolc/[dm.sup.3], [Al.sup.3+] (KCl 1 mol/L) 0.60 cmol,/[d.sup.m3], H+ Al (Ca acetate 0.5 mol/L) 4.65 cmolc/dm3, SB 7.89 [cmol.sub.c]/[dm.sup.3], CEC 12.54 cmolc/[dm.sup.3], V 63%, organic matter 23.10 g/[dm.sup.3], Cu 26.87 mg/[dm.sup.3], Zn 30.06 mg/[dm.sup.3], Mn 87.77 mg/[dm.sup.3], and Fe 21.60 mg/[dm.sup.3].
The surface layer (0 to 20cm) of an Oxisol (Typic Ustox) (Soil Survey Staff, 1998) was collected from an area of native vegetation (geographic coordinates: S 16[degrees]54'14.99" and W 43[degrees]57'41.28"and altitude of de 678m), municipality of Montes Claros, Minas Gerais State.
The soil used was a Latossolo Vermelho Distroferrico or an Ustox (American Classification Soil Taxonomy) with the following attributes: organic matter content - 60,31 g.
A water retention curve for a Brazil Ustox (Bui et al.
The dominant suborders of Oxisols are Aquox, Torrox, Udox, and Ustox (Table 3-5).