The results of the mirror image procedure showed that in the
control (treatment I), approximately 25% of the amino acids added
were mineralized after three days of incubation (Fig. 1a), indicating
that the remaining 75% of the amino acids added were taken up
directly. During the incubation the proportion of amino acid N
mineralized increased to about 30% (Fig. 1a), suggesting that the
MIT route became slightly more important with time. However,
variability was marked (Fig. 1a).