Table 1: Initial soil fertility conditions at Perkins, Haskell, and Lahoma, Oklahoma. Soil fertility is characterized by extractable sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), aluminum (AlKCl), effective cation exchange capacity (ECEC), and aluminum saturation (Alsat).

LocationNaKCaMgAlKClECECAlsat
mg kg−1cmolc kg−1%

Perkins11371750.90.281.3
Haskell25926429.40.6231.5
Lahoma201362290.10.670.1