Effect of gypsum on the utilization of nitrogen applied to an irrigated pasture on a relatively impermeable soil

Abstract

The effect was studied of a dressing of six metric tons of gypsum a hectare on the utilization of nitrogen applied to an irrigated pasture on a soil with a relatively impermeable subsoil. Gypsum increased yield and herbage nitrogen at higher levels of applied nitrogen when conditions were such as to promote rapid growth, but not otherwise. Thus the utilization of nitrogen was improved. It is suggested that this may have been due to a reduction in the duration of poor aeration in the soil after irrigation. The gypsum increased the recovery of nitrogen from 45 to 60 per cent after an application of 224 kg N per hectare.