The Environmental Policy Integrated Climate (EPIC) model with newly-developed biochar algorithms was used to determine the impacts of biochar amendments on corn (Zea mays L.) yields, soil cation exchange capacity (CEC), pH, bulk density (D-b) and soil organic carbon (SOC) dynamics. The objectives were (1) to determine biochar impacts on crop yields and soil properties of a tropical soil and (2) to evaluate biochar's potential as a climate change adaptation tool. EPIC was validated using results of a 4-yr experiment performed on an Amazonian Oxisol amended with biochar at rates of 0, 8, and 20 Mg ha(-1). Simulated yields of corn on biochar amended soil were significantly greater than control yields (p < 0.05). Simulated soil pH increased from original 3.9 to 4.19, CEC increased from 9.76 to 11.5 cmol(c) kg(-1), and SOC also increased. After validation, EPIC was used to simulate the impacts of the same biochar rates applied at 4 year intervals on corn yields and soil properties over the next 20 years. Soil CEC increased from 11.1 cmol(c) kg(-1) to 20.2 cmol(c) kg(-1) for the highest biochar application rate. Soil pH increased from 3.9 to 5.64. SOC increased up to 2.59 % for the highest biochar application rate with decreased topsoil D-b from 1.11 Mg m(-3) to 0.97 Mg m(-3). Long-term corn yields were slightly decreased. Although the results are biochar-, dose-, and soil-specific, biochar additions to tropical soils hold promise as a climate change adaptation tool resulting in increased soil carbon sequestration and improved soil properties.
Lychuk, TE; Izaurralde, RC; Hill, RL; McGill, WB; Williams, JR
Biochar as a global change adaptation: predicting biochar impacts on crop productivity and soil quality for a tropical soil with the Environmental Policy Integrated Climate (EPIC) model
Mitigation And Adaptation Strategies For Global Change