Incubation experiments were conducted to evaluate the effects of
biochar on the physiochemical properties of soil. Fifteen kg samples
of the study soils were placed in plastic pots (measuring approximately 30 cm in width and 40 cm in depth) and then mixed with biochar at three application rates (0%, 2.5% and 5% (w/w)). Soil and biochar were mixed thoroughly, and then wetted with deionized water to approximately 60% water content (i.e., the field water capacity of the soil). The unamended control was also subject to disruption of mixing. The incubated pots were placed in a room at 28 °C and weighed every 5 d to maintain a constant moisture content. All treatments were carried out in triplicate. The incubation time was 105 d in total, and soils were analyzed at 21 d, 42 d, 63 d, 84 d, and 105 d to determine their physical and chemical properties.