Rising Plate Meter as a Tool for Pasture Dry Matter Estimation: Case Study in Mediterranean Dryland Pastures

Abstract

In ruminant-based extensive livestock systems, pastures are one of the main components and the main feeding source given that they are the most eco-nomical resource. Accurate information about pasture dry matter (DM, in kg ha-1) availability is a key parameter in the manager’s decision, particularly when calculating stocking rates and supplementation needs. This study evaluates an electronic sensor (rising plate meter, RPM) to estimate DM in biodiverse dryland pastures. The study was carried out between December 2023 and December 2025 on three pasture fields, two located in Portuguese Alentejo region (Southern Portugal), “Mitra” and “Tapada dos Números”, and one located in Spanish Extremadura region (Cubillos). The experimental work consisted of sensor measurements, followed by the collection of more than 200 pasture samples, distributed between different dates of the pasture vegetative cycles of 2023/2024 and 2024/2025. The best estimation models for DM were obtained based on measurements carried out in Autumn and Winter (R2 > 0.70) and decreased significantly when based on measurements carried out in Spring. These results show the potential for the research and development of proximal and remote sensing tools to support pasture moni-toring and animal production management.