Abstract
The nature and distribution of total nitrogen, inorganic forms of and acid hydrolysable in five profile samples of Trinidad soil were studied. The total soil nitrogen was not fully measured by the Kjeldahl total method and prior treatment with HF(5·0N HF +0·75N HCl +0·6N H2SO4) led to the recovery of up to 58·0 per cent additional , possibly from fixed NH4-N The decrease in C/ ratio with depth was attributed mainly to fixed NH4-N in the soil. The proportion of total as hydrolysable ammonium, hexosamine, hydroxyamino acid, and ?-amino acid in the 6N HCI hydrolysable varied considerably among soils. The significant correlations of the hexosamine, hydroxy-amino acid and ?-amino acid with mineral (exchangeable NH4 + NO3) showed that these organic forms may contribute to the potentially available N in Soil.
