ELEMENT COMPOSITION OF HERBAGE AT URINE PATCH SITES IN A RYEGRASS PASTURE

The variation in the sodium, potassium, calcium, magnesium, zinc, iron, manganese, copper, phosphorus and nitrogen concentrations in autumn regrowth herbage across a perennial ryegrass (Lolium perenne) pasture has been measured. The regrowth resulting from urine return by sheep to a pasture takes the form of an ‘ island’ of herbage in which nitrogen (27) and potassium (28) are significantly higher than, and calcium (20), magnesium (10), phosphorus (24), and manganese (40) are significantly lower than in the surrounding herbage. Because of the selective grazing behaviour of sheep the possible implications for animal health of this pattern of element composition across a pasture are discussed. © 1979, Cambridge University Press. All rights reserved.