Validation of GRASSMASTER II for measurement and mapping of dry matter yield in Mediterranean pastures

Abstract

Grazing management and planning of animal production systems from pastures are essentially based on estimated herbage mass, production and accumulation rates. Understanding how spatial and temporal variability of animal, forage, soil and landscape features affect grazing behaviour and forage utilization provides potential to modify pasture management, improve efficiency of utilization, and maximize profits. The main objective of this study was to evaluate a commercial capacitance probe (GRASSMASTER II) for measuring pasture dry matter yields under Mediterranean conditions. The field tests were carried out on different dates (phenological stages), and on divers farms, representing typical pastures in the region (grasses; legumes; and bio-diverse flora, mixture of grasses, legumes and others species). Regression equations were used to relate the directly measured green and dry matter mass with the indirect estimates obtained using a Grassmaster II capacitance probe. The results indicated that the capacitance probe together with a GPS receiver might support site-specific management of pastures which would be useful to monitoring large areas.