EuroCrops v2.0: Multi-annual harmonized parcel level crop type data linked to European Union-wide survey, statistical and Earth Observation products

Abstract. As part of the Common Agricultural Policy (CAP) of the European Union (EU), farmers make annual declarations of the agricultural activities for which they receive subsidies. The declarations include the crops they grow at parcel level, referred to as Geo-Spatial Application (GSA) data. Paying Agencies (PA) of every EU Member State (MS) use specific crop classifications in their native language, and not all provide access to the GSA data. In the past, the EuroCrops initiative harmonized openly available GSA data for a single year (2021) using the Hierarchical Crop and Agriculture Taxonomy (HCAT), but multiple years are available depending on the country. Harmonizing a time series of farmers' crop declarations at parcel level would allow for comparative spatiotemporal analysis across the EU, the development of indicators that can be used for CAP and other policy monitoring purposes, and would provide data for training and validation of remotely sensed products. Here we have collected the GSA crop type declarations and parcel geometries that are publicly available from 18 PAs, the administrative bodies managing GSA data, for a minimum of three years. We have then harmonized the GSA data using HCAT v.4, a new version developed as part of this work. The data set includes nearly 47 million parcels covering 21 Mha. To facilitate integration and interoperability of the GSA data with other EU data sets containing spatial information on crops, we harmonized the crop classes used in the following data sets with HCAT v.4: 1) LUCAS, 2) the Integrated Farm Statistics/Farm Structure Survey, 3) the Farm Accountancy Data Network (FADN), and 4) the classification systems of the Copernicus High Resolution Layer on Crop Types. To demonstrate the potential of the multiannual, harmonised dataset presented in this paper, the GSA data were aggregated to NUTS 2 regions and compared with statistics on crop areas from Eurostat, showing good correspondence for many crops but also highlighting those crops and countries where the agreement is less good, providing possible reasons why. The data can also be used for mapping crop rotations, and a map showing maize monoculture illustrates this application. Farmers' declarations will increasingly become available as MS are required to publish these under the High-Value Dataset regulation. The EuroCrops v2.0 data set is registered and publicly available under the DOI https://doi.org/10.2905/b9fb9e67-78a9-4327-9d59-39a928d812d3.