Nitrate Content of Herbage at Different Manurial Levels

Abstract

FOLLOWING on the results reported in Nature ¹ nitrate nitrogen determinations have recently been made on herbage samples provided by Dr. Rice Williams, of the National Agricultural Advisory Service, from an experiment where sulphate of ammonia had been used at six levels, 0, 2, 4, 6, 8 and 12 cwt. per acre, to swards consisting of a number of different grass mixtures². Nitrogen was applied in mid-April and the herbage was cut six weeks later. The results from one of these mixtures (mixture B) are illustrated in Fig. 1. Mixture B was seeded down with Italian ryegrass, perennial ryegrass S.101, timothy S.48, cocksfoot S.26, S.143, S.37 and Danish, red clover S.123, alsike, white clover S.100 and S.184. The experiment was in the form of a randomized block, each level of application having three replicates. It is seen that nitrogen, applied in the ammonium form, and with a normal interval between application and cutting, has resulted in accumulations of nitrate nitrogen detectable at the 4-cwt. level and considerable at the 8- and 12-cwt. levels.