THE NON-PROTEIN NATURE OF A FRACTION OF SOIL ORGANIC NITROGEN

Abstract
It is shown that not all the nitrogen in organic soils is determinable by the Kjeldahl method. In every sample tested the Dumas method gave a considerably higher percentage of nitrogen.The differences in nitrogen content, as shown by the two methods, vary from 6.4 to 29.6%, hence it is believed that an appreciable fraction of the soil organic nitrogen may be of non-protein nature.