Build-up and Decline of Ammonia and Acidity in Grass after Successive Sowings and Regrowth

Abstract

THE concomitant build-up and decline of ammonia and acidity during the early growth stage of the grass Setaria sphacelata has already been reported¹. This behaviour did not occur with another grass Brachiaria ruziziensis grown under identical field conditions and similar in chemical constitution. The next step was to determine whether this behaviour would reoccur after a second sowing of the grasses in 1962 and also during regrowth following application of ammonium sulphate (2 cwt/acre) after the mature grasses grown in 1961 had been cut back. This would show whether the behaviour with Setaria was due to abnormal soil or climatic conditions or to an inherent property of the grass.