There is a well-known paradox in Spanish agriculture: the farmers who most need to digitalise their management are precisely those who work in areas with the poorest mobile coverage. Narrow valleys in Castilla y León, inland mountain ranges, irrigated land far from urban centres. When the field technician arrives at the plot with a tablet and the application does not load, the paper notebook wins again. This article explains how a digital field notebook software without coverage should work so that does not happen, and what you should demand from any solution before deploying it on your farm.
Why offline mode is not an extra, but a basic requirement
In Spain, according to data from the Ministry of Agriculture (MAPA) and the survey on ICT use in the agricultural sector, more than 40 % of dryland farms in Castilla y León, Extremadura and Aragón report poor or no mobile coverage on at least some of their plots. The problem worsens on farms with several scattered plots: the main building may have 4G, but the hillside vineyard plot may not even have 2G.
The Digital Farm Record has been mandatory in Spain since 1 January 2023 for certain farms under Royal Decree 1054/2022, and its progressive roll-out affects all agricultural and livestock farms that apply for CAP aid or use plant-protection products. This makes offline functionality a regulatory compliance issue, not just an operational convenience.
A solution that only works with a network is not a solution: it is an office tool disguised as a field application. And when it fails in the field, the farmer records on paper and then has to transcribe everything, doubling the workload and multiplying errors.
Technical architecture of offline mode: what lies behind it
Offline mode in a good field notebook software is based on three components working in a coordinated way:
1. Local database on the device
The application must maintain a local copy of all campaign data: plots, crops, planned treatments, registered plant-protection products and machinery. This copy is updated every time the device has a connection. When the network is lost, the app works on this local database with complete normality. The most common technologies for this are SQLite (for native iOS/Android applications) or IndexedDB/PouchDB databases in progressive web apps (PWA).
A critical point: the size of this local cache. A complete field notebook for a 200-hectare farm with 30 plots, including SIGPAC data for each parcel and the history of the past three years, can amount to between 50 and 200 MB of data. For low-cost devices or older tablets with limited storage, this can be a problem. Always ask the provider how much space the offline cache takes up and whether it can be segmented by campaign.
2. Downloaded SIGPAC cartography
The Geographic Information System for Agricultural Plots (SIGPAC) is the official reference for the identification of agricultural parcels in Spain. A serious field app must allow users to download SIGPAC maps for the provinces or municipalities where the farmer operates, so they can be consulted without a connection.
This has an important implication: SIGPAC data is updated periodically (FEGA publishes annual and partial updates). The application must manage these updates automatically when there is a network connection, and warn the user when working offline with a version that may be out of date. Some solutions add orthophoto layers from the IGN's PNOA (National Aerial Orthophotography Plan), which greatly facilitates the visual identification of parcels in the field.
For field work on own plots in our digital field notebook service we configure prior cartography downloads by province or municipality, adapted to the real scope of each farm.
3. Bidirectional synchronisation when the connection is restored
This is the most delicate point. When the device reconnects to the network, it must send all records created in offline mode to the central server. But what happens if two technicians have worked on the same plot without a connection and have recorded different data? The application needs a well-defined conflict resolution system.
The most common strategies are:
- Last-write-wins: the last record sent overwrites the previous one. Simple, but dangerous if several technicians are working in parallel.
- Field-by-field merge: the system tries to combine records field by field, flagging conflicts for manual review. More complex but safer.
- Append-only record: all offline entries are queued and applied as sequential operations, maintaining complete traceability. This is the most recommended pattern for field notebooks with probative value before the authorities.
Ask your provider to explain exactly what happens when there are synchronisation conflicts. If they do not have a clear answer, be wary.
What can be recorded offline and what cannot
Not all functions of a digital field notebook are compatible with offline mode. This table summarises the typical capabilities:
| Function | Full offline | Partial offline | Requires connection |
|---|---|---|---|
| Viewing and editing own SIGPAC plots | ✓ | ||
| Recording phytosanitary applications | ✓ | ||
| Recording cultural operations (sowing, irrigation, pruning) | ✓ | ||
| Consulting authorised plant-protection products (REGA) | ✓ (cache) | ||
| GPS geolocation of parcels | ✓ | ||
| Consulting MAPA phytosanitary alerts | ✓ | ||
| Generating and sending reports to the authorities | ✓ | ||
| Consulting weather forecasts | ✓ | ||
| Integration with agrometeorological stations | ✓ (last reading) | ||
| Electronic signature of records | ✓ |
The distinction between full offline and partial offline (cache) is important: in cache mode, the app displays data downloaded at the last synchronisation, but cannot guarantee that it is up to date. For the MAPA Plant-Protection Products Register, this can be critical if a product has been suspended since the last synchronisation.
SIGPAC integration: how parcels should work without a network
SIGPAC identifies each plot using a composite reference made up of province, municipality, aggregate, zone, polygon and parcel. A well-designed offline app must allow the technician to:
- Locate their GPS position and have the app automatically identify the SIGPAC parcel they are in, without needing a network.
- View the parcel boundary on the downloaded orthophoto, to verify they are on the correct plot.
- Consult parcel data: eligible surface area, declared use, admissibility coefficient, whether it is in a nitrate-vulnerable zone, whether it belongs to Natura 2000, etc.
- Start recording an operation directly from the parcel view, automatically pre-filling the SIGPAC identifier in the form.
This workflow seems simple, but it requires the app to have previously downloaded not only the parcel geometry, but also all the associated alphanumeric attributes. Some applications only download geometries and leave attributes as online queries, which makes essential functions unusable when there is no network.
GPS and field accuracy: what is sufficient and what is not
The GPS of a standard phone or tablet has an accuracy of between 3 and 10 metres under normal conditions, which can degrade to 15–20 metres under tree canopies or in narrow valleys. For most field notebook operations (assigning a task to a parcel, recording the start and end of an application), this accuracy is more than sufficient.
Where accuracy becomes relevant is in creating new parcels or documenting operations that require precise coordinates (for example, the exact location of a pest monitoring trap or a soil sample point). For these cases, some solutions integrate with external high-precision GNSS receivers (RTK or DGNSS) that connect via Bluetooth to the device and offer centimetre-level accuracy.
Real-world use cases where offline makes the difference
Phytosanitary applications during night-time treatments
Many pest treatments are carried out at dawn or in the final hours of the afternoon to take advantage of optimal weather conditions (wind < 3 km/h, temperature < 25 °C). At that time, the technician operating the machinery cannot wait for coverage to record the treatment. Offline mode allows recording product, dose, treated area and conditions at the moment of application, and synchronising when the tractor returns to the yard with Wi-Fi.
Phytosanitary advisory visits to remote plots
The Regulation on the Sustainable Use of Pesticides (EU 2009/128/EC and its revision under discussion in 2025–2026) requires certain farms to have the advice of a qualified technician. That technician needs to record their visits, observations and recommendations in the notebook. If they work in an area without a network, the alternative is paper or an offline app.
Data collection for integrated livestock notebooks
Mixed farms (agriculture + livestock) must also maintain the livestock notebook. Animal movements between grazing areas, medication administration in the field and health records in scrubland areas are exactly the type of operations that occur without coverage.
What to look for before choosing field notebook software
Beyond offline mode, there are other technical criteria that affect the real viability of a solution. At Summum Sistemas, with more than nineteen years supporting agri-food companies and primary sector farms in Castilla y León and the Canary Islands, we recommend evaluating these points:
- MAPA approval: the software must be recognised by the Ministry of Agriculture for records to have administrative value. Consult the official list of recognised applications.
- Compliance with the mandatory digital farm record: the solution must cover the minimum fields required by Royal Decree 1054/2022 and subsequent amendments.
- Data export: you must be able to export your data in a readable format (PDF, Excel, XML) to present to the authorities or switch tools in the future.
- Multi-user management and profiles: on farms with several technicians, the solution must allow differentiated permissions to be assigned (who can record applications, who can only view).
- Integration with ERP or management software: if the farm uses an agri-food ERP, bidirectional synchronisation between the field notebook and cost accounting is a significant advantage. Our digital field notebook service includes this integration from the design phase.
- Technical support in Spanish and proximity: the farmer who has a problem in the middle of a treatment campaign cannot wait days for a resolution.
Frequently asked questions
Is the digital field notebook mandatory in Spain in 2026?
Royal Decree 1054/2022, of 27 December, established the obligation of the digital farm record for agricultural farms applying for CAP aid, with a progressive implementation schedule. From 2026, the obligation has also been extended to farms that apply plant-protection products, regardless of whether they apply for aid. Regional regulations may add further requirements: in Castilla y León, the Regional Ministry of Agriculture has been promoting adoption since 2023 through its advisory programmes.
What happens if I record a phytosanitary application offline using a product that is no longer authorised?
This is a legitimate concern. Good software handles this in two ways: it periodically downloads the updated list of authorised products from the MAPA Plant-Protection Products Register and stores it in cache, and it displays a clear warning when the last update exceeds a time threshold (for example, 7 days). If a product has been suspended and the technician records it offline without knowing, the system must flag it as pending verification at synchronisation. In no case does the software relieve the user of the responsibility of verifying current authorisations.
Does GPS work without mobile coverage?
Yes. GPS is a technology independent of the mobile data network: the satellites of the GPS (American), Galileo (European), GLONASS (Russian) or BeiDou (Chinese) systems broadcast signals that the device receiver picks up directly, without going through any telecommunications operator. What does require an internet connection is downloading assistance data (A-GPS) that speeds up the initial location fix, but once the receiver has a fixed position, it maintains tracking without a network. Accuracy may be slightly lower without A-GPS, but it remains valid for field use.
Can the farmer manage several farms from the same app in offline mode?
It depends on the solution. The most robust applications allow independent farm profiles to be created (with their respective SIGPAC plots and configurations) and the data for several of them to be downloaded offline simultaneously. This is important for technical advisors and ATRIAs (Associations for Integrated Treatment in Agriculture) who manage the phytosanitary care of several farms belonging to different owners. In those cases, access permissions and data separation between farms are privacy and compliance requirements that the app must guarantee.