| Abstract: | In model experiments (60 % water holding capacity and 30°C) with a loamy clay (pH 8.3) and a calcareous sand (pH 7.9) the effect of biuret upon the breakdown of urea was studied. Ammonification and nitrification occured very quickly, in case of the calcareous sand at the beginning more NH4 was evolved. Biuret in concentration from 0.4 to 8 % maximum did not influence urea hydrolysis, however it resulted in higher NO2-figures at the beginning of the experiments demonstrating an initial marked inhibition of the process NO2 → NO3 especially in the calcareous sand. The total nitrification seemed to be a little retarded but did not differ very much finally. |
