Fields of The World: A Field Guide for Extracting Agricultural Field Boundaries
Isaac Corley, Hannah Kerner, Caleb Robinson, Jennifer Marcus
TL;DR
The paper addresses the need for scalable, accurate field boundary extraction to support agricultural monitoring and deforestation screening. It introduces the Fields of The World (FTW) benchmark, comprising 1.6M field polygons across 24 countries, pre-trained segmentation models using bi-temporal Sentinel-2 imagery, and open-source inference tools. Two notebooks illustrate end-to-end workflows: local-scale boundary inference with crop classification and forest loss attribution, and country-scale exploration of pre-computed predictions stored in cloud-native Zarr archives. The results show macro-F1 scores of 0.65–0.75 for crop-type classification with limited labels, and demonstrate per-field forest loss attribution and efficient year-over-year change detection at continental scales, enabling practical, scalable agricultural monitoring and policy analysis.
Abstract
Field boundary maps are a building block for agricultural data products and support crop monitoring, yield estimation, and disease estimation. This tutorial presents the Fields of The World (FTW) ecosystem: a benchmark of 1.6M field polygons across 24 countries, pre-trained segmentation models, and command-line inference tools. We provide two notebooks that cover (1) local-scale field boundary extraction with crop classification and forest loss attribution, and (2) country-scale inference using cloud-optimized data. We use MOSAIKS random convolutional features and FTW derived field boundaries to map crop type at the field level and report macro F1 scores of 0.65--0.75 for crop type classification with limited labels. Finally, we show how to explore pre-computed predictions over five countries (4.76M km\textsuperscript{2}), with median predicted field areas from 0.06 ha (Rwanda) to 0.28 ha (Switzerland).
