(DNRA) especially under slightly anaerobic conditions and in the presence of a wide C to NO3 ratio. On the other hand, N2O emissions can decrease in the presence of char materials which might favour the last step in denitrification, thus decreasing the ratio of N2O/N2þN2O in soil N emissions. This effect, however,seems to be dependent on the nature of the added soil amendment,since other authors found increases in N2O emissions in the presence of hydrochar char while pyrochar decreased these emissions.