In addition to soil pH, the CEC significantly increased from 7.41 to
9.26 (2.5%) and 10.8 cmol (+) kg−1 (5%) (p b 0.05) with the application
of biochar. The biochar-amended soils also showed an increase in
the CEC with incubation time (Fig. 2c). The exchangeable K, Ca, and
Mg contents also significantly increased in the biochar-amended soil
compared with the control. Both biochar application rates increased
the BS from 6.40% to 14.2% (2.5%) and 26.0% (5%) (p b 0.05) after incubation
of 105 d, indicating an increase in the nutrient status of
highly weathered soils after biochar application.