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

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. Copyright Springer Science+Business Media Dordrecht 2015