The Simulation of Animal Returns in Grassland Experimentation

Abstract

An experiment was carried out on a grass/whiteclover sward at North Wyke to evaluate the use of mixtures of inorganic and organic nutrient sources to simulate the nutrient effect of animal excreta, both with and without overaU PK fertilizer. Grazing with sheep and the return of excreta from caged sheep both increased herbage yields, as did artificial return treatments. Artificial return treatments giving 75% ofthe nutrient level returned by excreta gave yields comparable with grazing. Ilie effect of the simulated return treatments was not influenced by PK application. Grazing gave a very different botanical composition to that from the treatments in wbich natural or simulated excreta were returned to cut swards.Mixtures simulating excreta may replace the nutrient effect of the grazing animal, but not its physical effect, in some forms of grassland experimentation. They are not recommended for fertilizer trials.

A Co-Operative Programme to Extend Lamb Production in Southland

“…It can be easily made during spring and summer and high quality silage is sufficient for finishing lambs (Fitzgerald 1986). Making silage can also improve production and white clover content of pasture (Wolton et al 1970). Because any form of conservation has associated costs and quality losses (Barry ef al.…”