Measuring Herbage Mass by Non-Destructive Methods: A Review

Resumo

Accurate assessment of herbage mass (HM) in pasture is a key to budgeting forage in grazing systems worldwide.Different non-destructive techniques to measuring pasture yield are commented. The methods compared include visual estimations,manual and electronic pasture meters and remote sensing. All methods are associated with a moderate to high error, showing thatsome indirect methods of yield estimation are appropriate under certain conditions. In general terms, no method was found as themost appropriate because many factors as climate variations, soil characteristics, plant phenology, pasture management and speciescomposition must be taken into account to make local calibrations from a general model. Best results were found modifying generalmethods under local calibrations and under local conditions. In order to give farmers the best method to manage adequately their owngrazing systems, researchers must select the most suitable technique considering the scale of operation, the desired accuracy and theresources available.