Field management
Abandoned field: telling it apart from planned fallow
A field counts as abandoned when no crop is grown on it for longer than normal fallow – by the accepted scientific definition, four or more seasons in a row. Instead of a crop, sparse weedy vegetation takes over, the soil is left bare or turns saline, and the land drops out of production. It is most common in the Aral Sea basin, Karakalpakstan and the lower reaches of the Amu Darya and Syr Darya.
When it is dangerous
This risk is not tied to a crop stage – it is judged over years, not within one season. Planned fallow in Central Asian rotations usually lasts 2–3 years, so a single empty season means little. A field is called abandoned once it stays empty for four seasons or more.
Causes
- Soil salinity
- Shortage of irrigation water
- Waterlogging and poor drainage
- Rural out-migration and land-use decisions
Signs on the field
- No seasonal green-up peak like a sown crop would show
- Low, flat greenness from sparse weedy vegetation
- Bare or salt-crusted soil
- Irregular greenness with no clear season
How ClusterOS notices it
ClusterOS reads the field history in Sentinel-2 optical images since 2019 and looks for a crop peak in NDVI, an index of green biomass. If there is no peak for several seasons and NDVI stays low, a warning appears first, and after four empty seasons a confident signal. In images, abandonment can be confused with planned fallow, long-term idle land or perennial grasses such as alfalfa, and a short or gappy image record makes the result unreliable. Borderline cases need a field check by an agronomist.
What to do
- Compare the signal with the rotation plan and mark the field if it is in planned fallow
- Visit the field and check for a crop, weeds or salt patches
- If salinity or waterlogging is the cause, assess leaching and drainage
- Decide whether to bring the field back into use or remove it from the sown area records
Questions
How do you tell an abandoned field from fallow?
Only by duration. Planned fallow in Central Asian rotations usually lasts 2–3 years, while a field is considered abandoned after four or more consecutive seasons without a crop. Perennial grasses such as alfalfa have their own curve in the images and look different from weedy regrowth.
Why can a satellite not detect abandonment in one season?
One empty season is normal in a rotation. A conclusion needs several seasons of field history without large gaps in the imagery, otherwise it is unreliable.
Learn about this risk on your fields before it becomes a loss
We will show ClusterOS on your own fields: history since 2019, crop stage and all 24 risks.
Other risks in «Field management»
Scientific basis
- Löw F., Prishchepov A.V., Waldner F., Dubovyk O., Akramkhanov A., Biradar C., Lamers J.P.A. (2018) Remote Sensing 10(2):159, DOI: 10.3390/rs10020159
- Dara A., Baumann M., Kuemmerle T. et al. (2018) Remote Sensing of Environment 213:49–60, DOI: 10.1016/j.rse.2018.05.005
- Verbesselt J. et al. (2010) Remote Sensing of Environment 114(12):2970–2980, DOI: 10.1016/j.rse.2010.08.003