Theme 2-2: Forage Production and Utilization--Poster Sessions
Description
A large portion of the sheep production systems in the semi-arid zone of Central Chile base their feeding on the rangelands, adjusting both the production cycle and the use of supplementary feed to the natural supply of fodder. In this way, knowledge of the rangeland quantity and quality at the farm level emerges as an essential input for the decision-making of feed management. The objective of the study was to relate the herbage quality parameters of the semi-arid zone rangeland with Vegetation Indices (VI) and to determine which vegetation index report the best results. Vegetative indexes were obtained from aerial images multispectral captured by a drone. During the 2018 growing season (Oct to Dec), in three farms of the semi-arid zone of Central Chile, three plots of exclusion (per farm) of 100 m2 each were installed and monitored. Samples were taken once a month to determine the contents of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) of rangeland herbage. Regressions were developed between the rangeland herbage quality parameters and the calculated VI. Most of the regressions obtained were significant (p < 0.05). In DM, the index that presented the best R2 (0.84) was Plant Senescence Reflectance Index (PSRI). In CP, the highest value of R2 was only 0.38 for PSRI. For NDF, a maximum value of R2 of 0.56 was obtained using Red Edge Chlorophyll Index (CI red edge). Finally, for ADF, the highest value of R2 was 0.72 obtained in Green Normalized Difference Vegetation Index (GNDVI), Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), and Green Chlorophyll Index (CI green).
Included in
Relationship between Semi-Arid Rangelands Quality Parameters and Vegetation Indexes
A large portion of the sheep production systems in the semi-arid zone of Central Chile base their feeding on the rangelands, adjusting both the production cycle and the use of supplementary feed to the natural supply of fodder. In this way, knowledge of the rangeland quantity and quality at the farm level emerges as an essential input for the decision-making of feed management. The objective of the study was to relate the herbage quality parameters of the semi-arid zone rangeland with Vegetation Indices (VI) and to determine which vegetation index report the best results. Vegetative indexes were obtained from aerial images multispectral captured by a drone. During the 2018 growing season (Oct to Dec), in three farms of the semi-arid zone of Central Chile, three plots of exclusion (per farm) of 100 m2 each were installed and monitored. Samples were taken once a month to determine the contents of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) of rangeland herbage. Regressions were developed between the rangeland herbage quality parameters and the calculated VI. Most of the regressions obtained were significant (p < 0.05). In DM, the index that presented the best R2 (0.84) was Plant Senescence Reflectance Index (PSRI). In CP, the highest value of R2 was only 0.38 for PSRI. For NDF, a maximum value of R2 of 0.56 was obtained using Red Edge Chlorophyll Index (CI red edge). Finally, for ADF, the highest value of R2 was 0.72 obtained in Green Normalized Difference Vegetation Index (GNDVI), Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), and Green Chlorophyll Index (CI green).
