The behaviour of nitrogenous manures in the soil Part I. The loss of manurial nitrogen

Abstract

An attempt was made to determine what becomes of the nitrogen added to a poor soil in moderate quantities of organic manures or of ammonium sulphate. Losses by drainage, in two successive barley crops, and by fixation in an unavailable form in the soil were determined, and it was found that with every material used (including tare residues containing 3½% nitrogen, mustard plant residues containing 1½–2¼ nitrogen and pure ammonium sulphate) and with intensive cropping and leaching, not more than 40–51% of the added nitrogen could be accounted for at the end of the experimental period. The balance, it is suggested, must have disappeared from the system, possibly as gaseous nitrogen. Incidentally to the above, it would appear that after the first crop of barley the presence of the manurial additions of tare residues, and especially of ammonium sulphate, tends to hinder the formation of leachable nitrogen in the soil.