The fitting of frequency distributions to height measurements on grazed swards


Mr M. J. Gibb, Animal and Grassland Research Institute, Hurley, Maidenhead, Berks., UK. SL6 SLR.


Herbage height was measured in ryegrass/white clover (Lolium perenne/Trifolium repens) swards grazed by cattle using the rising plate meter or the sward stick. Ordinary single normal and double normal distributions were fitted to the data obtained. After the first 6 weeks of continuous grazing the double normal distributions fitted data for the taller swards better than the single normal distribution did, but for a short sward there was no improvement. There was no improvement due to the use of the double normal distribution with data for swards grazed by sheep.