[1] Texas A&M Univ, Dept Soil & Crop Sci, College Stn, TX 77843 USA
[2] Univ Sydney, Fac Agr & Environm, Eveleigh, NSW, Australia
[3] Univ Sydney, Soil Carbon Initiat, United States Studies Ctr, Sydney, NSW, Australia
[4] Wageningen Univ, Dept Soil Inventorisat & Land Evaluat, Wageningen, Netherlands
[5] INERIS, Div Sci, Verneuil En Halatte, France