Improving the mapping of field and farm size will allow for step-change in our understanding of the role of farm size in agricultural dynamics, the effects of different governance interventions aimed at rural development, food security, and balancing environment and development goals, the impacts of heterogeneity and inequalities in the internal distribution of land for different ranges of farm sizes, and the evolution of average farm size over time. The overarching goal of this research is to improve the understanding of the role of field and farm sizes in dynamics of land use, livelihoods and sustainability, by (i) developing algorithms and a workflow to map field sizes from remote sensing data in smallholder-dominated landscapes of Sub-Saharan Africa, over large areas and across time series, (ii) applying this workflow to produce such maps for two large regions in contrasted environments, and (iii) analyzing the dynamics of land use change revealed by these maps. This work will demonstrate the potential for field size mapping at scale relevant for policy-making and sustainability assessments, and open the way for the first wall-to-wall continental field size map of Sub- Saharan Africa.

Project outcomes

Datasets:

Rufin, P., Bey, A., Picoli, M., Meyfroidt, P. (2022). A map of active cropland and short-term fallows across Northern Mozambique for 2020/2021 derived from PlanetScope data https://doi.org/10.5281/zenodo.6907606

Rufin, P., Meyfroidt, P. (2024). Satellite-derived crop field boundaries in heterogeneous smallholder-dominated regions in the North of Mozambique. https://doi.org/10.5281/zenodo.11488975

Scientific papers:

Rufin, P., Wang, S., Nogueira Lisboa, S., Hemmerling, J., Tulbure, M. G., Meyfroidt, P. (2024) Taking it further: leveraging pseudo labels for field delineation across label-scarce smallholder regions. International Journal of Applied Earth Observation and Geoinformation, 134, 104149 https://doi.org/10.1016/j.jag.2024.104149

Chiarella, C., Rufin, P., Abeygunawardane, D., Bey, A., Lisboa, S. N., Zavale, H., Meyfroidt, P. (2024) Impacts of large-scale forestry investments on neighboring small-scale agriculture in northern Mozambique. Land Use Policy, 145, 107251. https://doi.org/10.1016/j.landusepol.2024.107251

Pratzer, M., Meyfroidt, P., Antongiovanni, M., Aragon, R., Baldi, G., Czaplicki Cabezas, S., De La Vega-Leinert, C. A., Dhyani, S., Diepart, J.-C., Fernandez, P. D., Garnett, S. T., Gavier Pizarro, G. I., Kalam, T., Koulgi, P., Le Polain De Waroux, Y., Marinaro, S., Mastrangelo, M., Mueller, D., Mueller, R., … Kuemmerle, T. (2024). An actor-centered, scalable land system typology for addressing biodiversity loss in the world’s tropical dry woodlands. Global Environmental Change, 86, 102849. https://doi.org/10.1016/j.gloenvcha.2024.102849

Jänicke, C., Wesemeyer, M., Chiarella, C., Lakes, T., Levers, C., Meyfroidt, P., Müller, D., Pratzer, M., & Rufin, P. (2024). Can we estimate farm size from field size? An empirical investigation of the field size to farm size relationship. Agricultural Systems, 220, 104088. https://doi.org/10.1016/j.agsy.2024.104088

Akinyemi, F., Rufin, P., Ibrahim, E., Hostert, P., Ogunsumi, L., Egbetokun, O., & Ifejika Speranza, C. (2023). Untangling intercropping in heterogeneous smallholder maize-cassava farming systems with remote sensing. https://doi.org/10.31223/X57T2M

Rufin, P., Bey, A., Picoli, M., Meyfroidt, P. (2022). Large-area mapping of active cropland and short-term fallows in smallholder landscapes using PlanetScope data. International Journal of Applied Earth Observation and Geoinformation, 112. https://doi.org/10.1016/j.jag.2022.102937.

Picoli, M. C. A., Radoux, J., Tong, X., Bey, A., Rufin, P., Brandt, M., Fensholt, R., & Meyfroidt, P. (2022). Unsupervised Segmentation of Smallholder Fields in Mozambique using PlanetScope Imagery. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, XLIII-B3-2022, 975-981. https://doi.org/10.5194/isprs-archives-XLIII-B3-2022-975-2022

Conference contributions:

Rufin, P. (2024): Leveraging Earth Observation for characterizing heterogeneous farming systems in Sub-Saharan Africa. IAMO Forum. Halle, Germany

Rufin, P., Meyfroidt, P. (2023): Transfer learning for smallholder field delineation and field size estimation in Sub-Saharan Africa. Tropentag. Berlin, Germany.

Akinyemi, F.O., Rufin, P., Ibrahim, E.S., Hostert, P., Ogunsumi, L.O, Egbe-Tokun, O.A., Ifejika Speranza, C. (2023): Mapping heterogeneous smallholder maize-cassava systems in southwest Nigeria based on Sentinel-1 and Sentinel-2 time series. Tropentag. Berlin, Germany.

Rufin, P., Picoli, M., Bey, A., Ubisse, Y., Lisboa, S. N., Sitoe, A., & Meyfroidt, P. (2022). Mapping field sizes in smallholder agriculture of Sub-Saharan Africa: Assessing pathways to overcome the mismatch between spatial resolution and field size. ESA Living Planet Symposium. Bonn, Germany.

Rufin, P., Picoli, M., Hostert, P., & Meyfroidt, P. (2022). Leveraging novel opportunities for operationalizing annual cropland mapping in smallholder systems of Sub-Saharan Africa: Analyzing NICFI PlanetScope mosaic time series in Google Earth Engine. ESA Living Planet Symposium. Bonn, Germany.

Picoli, M.C.A., Tong, X., Radoux, J., Bey, A., Rufin, P., Brandt, M., Fensholt, R., Meyfroidt, P. (2022). Mapping field size in the emerging agricultural frontier of Southern Africa: New insights from the MIDLAND project. ESA Living Planet Symposium. Bonn, Germany.