Nitrogen Loss from Soils and Oxide Surfaces

IT has been reported1 that when a virgin soil is brought under cultivation, the percentage of total nitrogen usually falls off with time up to a limiting value. A loss of nitrogen from soils on the addition of nitrogenous compounds, especially when the conditions are favourable for oxidation, has also been observed by different investigators; but this phenomenon has been explained satisfactorily by Dhar and collaborators2, who have postulated that this type of nitrogen loss in soils is chiefly due to the formation and decomposition of the unstable ammonium nitrite produced in the processes of ammonification and nitrification. There is also the possibility of the reaction of nitrous acid on amines, amides and amino-acids which may sometimes be present in the soil or formed in the decomposition of soil organicsubstances. It has also been reported that soil loses nitrogen in the form of nitrogen gas much less when manured with sodium or potassium nitrate than when treated with ammonium sulphate, urea or other organic nitrogenous manures.