Crop yield and SOC responses to biochar application were dependent on soil texture and crop type in southern Quebec, Canada

Changes to soil nutrient availability and increases for crop yield and soil organic C (SOC) concentration on biochar-amended soil under temperate climate conditions have only been reported in a few publications. The objective of this work was to determine if biochar application rates up to 20 Mg ha(-1) affect nutrient availability in soil, SOC stocks and yield of corn (Zea mays L.), soybean (Glycine max L.), and switchgrass (Panicum virgatum L.) on two coarse-textured soils (loamy sand, sandy clay loam) in S Quebec, Canada. Data were collected from field experiments for a 3-y period following application of pine wood biochar at rates of 0, 10, and 20 Mg ha(-1). For corn plots, at harvest 3 y after biochar application, 20 Mg biochar ha(-1) resulted in 41.2% lower soil NH4+ on the loamy sand; the same effect was not present on the sandy clay loam soil. On the loamy sand, 20 Mg biochar ha(-1) increased corn yields by 14.2% compared to the control 3 y after application; the same effect was not present on the sandy clay loam soil. Biochar did not alter yield or nutrient availability in soil on soybean or switchgrass plots on either soil type. After 3 y, SOC concentration was 83 and 258% greater after 10 and 20 Mg ha(-1) biochar applications, respectively, than the control in sandy clay loam soil under switchgrass production. The same effect was not present on the sandy clay loam soil. A 67% higher SOC concentration was noted with biochar application at 20 Mg ha(-1) to sandy clay loam soil under corn.