Addition of Biochar Did Not Reduce Nitrous Oxide Emissions or Nitrogen Leaching from Peat Soil

Abstract

Drained agricultural peat soils pollute both the atmosphere and watercourses. Biochar has been observed to decrease GHG emissions and nutrient loading in mineral soils. We studied effects of three biochar types with two application rates on GHG fluxes as well as N and P leaching on peat soil. Peat monoliths were drilled from a long-term cultivated field and were watered either slightly (four dry periods) or heavily (four rainfall periods) during the 11-month experiment. The incubation of bare peat profiles enhanced peat decomposition leading high CO2 and N2O emissions and NO3-N leaching in all treatments. Despite the potentially suitable biochar characteristics and soil conditions, none of the biochars or their application rates significantly affected gas fluxes or nutrient leaching. These results indicate that biochar application does not help to solve the environmental problems of agricultural peat soils.

Keywords: peat, biochar, greenhouse gases, nutrient leaching