The analyses methods were as follows: soil pH in water was determined in a 1:2.5 (w/v) soil:water suspension; SOC and TC (%) were determined by chromic acid digestion and spectrophotometric analysis; TN (%) was determined from a wet acid digest and analyzed by colorimeter; exchangeable Ca, K and Mg were extracted using the Mehlich-3 procedure; CEC was determined by ammonium acetate at pH 7. Boron was extracted using CaCl2 and the resulting extract analyzed calorimetrically using a spectrophotometer.