Nitrate Content of some Grass Species and Strains

Abstract

IN the course of an investigation into possible sources of error in the determination of crude protein in herbage by the conventional method, a number of determinations of nitrate nitrogen were made. It is customary in this laboratory to use a reference herbage sample as a check in the routine. The nitrate nitrogen in this was determined first and found to be approximately 0.1 per cent. The reference sample is bulked from a large number of herbage samples, mainly grass, which pass through this laboratory. A nitrate content of this magnitude is therefore an average figure for several hundred samples and implies that some of the herbage which contributed to the reference sample may have contained considerable (possibly even nutritionally unacceptable) amounts of nitrate nitrogen.