Sequential sampling protocol for monitoring pasture utilization using stubble height criteria

Stubble height, a measure of the amount of vegetation remaining after grazi ng, is thought to be a useful variable in the management of riparian areas, A number of riparian and grazing processes appear to be directly or indire ctly affected by the residual stubble height. Thus, average stubble height is often used to evaluate the Livestock impact a pasture has received, part icularly in riparian zones. Stubble height sampling methodology has receive d little previous attention. A sequential sampling procedure for stubble he ight was investigated. The procedure provides statistically defensible answ ers in the shortest possible amount of time. The procedure does not require a rigid sample size and involves simple yes/no answers at each observation . A small initial sample of readings is selected and evaluated. If there is sufficient information to make a clear decision, then grazing is either co ntinued or stopped. If the initial evidence does not clearly support either decision, then sampling proceeds. This may continue for several iterations before a decision is reached. Statistically supportable decisions can typi cally be made within a short time frame using this method. This method may also be applied to evaluate trampling and other yes/no responses.