Influence of biochar produced from different pyrolysis temperature on nutrient retention and leaching

Biochar application has been received much attention because biochar can improve the fertilizer utilization efficiency of soil. However, the effect of biochar produced at different temperature on the nutrient retention and leaching remains poorly understood. In this study, we observed the nutrients leaching from a sandy loam soil amended with biochar produced at different temperature. The properties of biochars produced from wheat straw at four contrasting pyrolysis temperatures (250, 350, 450, and 550 degrees C) showed that increasing pyrolysis temperature increased pH value and specific surface area but reduced the electrical conductivity and cation exchange capacity. With the temperature increased, the nitrogen loss was significant decreased (p>0.05) from 109.6mg to 53.3mg in biochar amended soil. However, dissolved organic carbon (DOC), available P, Na and K were significant increased (p>0.05). These results demonstrate that the pyrolytic temperature has a great influence on biochar properties, which in turn affect the leaching of the available nutrients.