Difficulty in measuring the mass of pasture dry matter yield per unit area per year drove this research, which used 4 years of Sentinel-2 satellite imagery and collected pasture yield measurements to develop a model of pasture productivity.
The model uses a Normalised Difference Vegetation Index (NDVI), with spatio-temporal segmentation and averaging, to estimate mean annual pasture productivity across all of New Zealand’s grasslands to within around 2.2 tonnes per hectare.
Researchers applied the model to field-level segments, enabling regional and local trends to be explored. Due to its ability to highlight areas of land use intensification suitability, the national map of pasture productivity is of value to landowners, land users, and environmental scientists.