Foliar macronutrient concentrations of eight perennial ryegrass (Loilium perenne L.) cultivars grown in four regions in New Zealand

Concentrations of nitrogen, phosphorus, potassium, calcium. magnesium, sulphur and sodium were measured in eight perennial ryegrass cultivars, grown at four sites in New Zealand. For the macronutrient analyses, herbage samples were collected from pure ryegrass plots, grown with two nitrogen fertiliser rates with three sites sampled in spring and all four sites in autumn. There were significant differences among the cultivars for all elements except potassium, extending the results of earlier research to commercial cultivars. It is suggested that breeding ryegrass for lowered shoot phosphorus concentration should be prioritised because of the economic and environmental benefits to be gained from farming with reduced phosphate fertiliser requirements.