AbstractOne of the greatest difficulties in pasture research is accurately measuring quality and quantity of the vegetation. The disk meter may be used to rapidly estimate herbage mass (DM) but its validity depends on a good relationship between disk meter height (DMH) and DM. The objective of this study was to determine the relationship between DMH and DM for continuously grazed pastures. Pastures of varied botanical composition were grazed by cows and calves from May through October. Paired data (DMH and DM clipped from under the disk) from seven cool season pastures were subjected to covariance analysis. Prediction equations were developed utilizing data from 2 years for different pastures and dates. Disk meter height accounted for a little over half the variability in DM (R2of 0.54 and 0.59 for years 1 and 2, respectively). Regression coefficients of DM on DMH differed between dates in both years and between pastures in one year. To accurately predict DM the disk meter must be calibrated for each pasture and date. However, the disk meter can be used where an estimate of herbage mass is required and resources are limiting.
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