Using cameras to improve the accuracy of root crop yield measurements
With the help of yield measurement systems on harvesters, it is increasingly possible to map yields on a location-specific basis. These systems are available and here are their costs.
If you want to determine how crop yields vary between fields or within a field, you need to map that variation. Yield measurement systems on harvesters and diggers allow for objective, quantitative, and sometimes qualitative assessments. They provide additional data, offering more (and deeper) insights into field conditions. Variations in yield can indicate differences in soil quality, planting and seeding distances, fertilisation levels, pest control measures, water availability, and, more generally, yield potential. However, drawing direct and definitive conclusions is not always possible due to crop rotation. This is also noted by farmer Anselm Claassen, who has experimented with various yield measurement techniques (see box below).
Weighing as a logical method
Weighing is a logical and proven method for determining gross crop yield in combination with GPS systems for location-specific results. Approximately 20 years ago, the Dutch (no longer existing) specialist Probotiq developed the first yield measurement system using load cells for potato harvesters. Vantage Agrometius (also Dutch) acquired this technology and developed a new ISOBUS-compatible system called YieldMasterISO, currently priced at €9,000. This system is available for harvesters of root crops such as potatoes and onions, as well as for grape and tomato harvesters. The manufacturer reports having installed the system on over 50 harvesters in the Netherlands, 60% of which are potato harvesters and 40% onion harvesters. Around 30 systems are used abroad for yield measurements during grape and tomato harvesting.
Factory-fitted options with certain manufacturers
Some harvester manufacturers, such as AVR and Grimme, offer factory-fitted yield measurement systems with load cells on (self-propelled) potato harvesters. AVR installs an in-house developed system with 2 load cells under the sieving table of the Puma self-propelled harvester, costing €4,900 when used with an existing GPS system for location determination. Approximately 80 Pumas are now equipped with this system, mostly in Belgium and the Netherlands but also in Germany and the UK.
Grimme offers the Topcon YieldTrakk system, which features 2 load cells under the sieving belt, for its Evo 280, AirSep 290, Varitron 470, and Ventor 4150 harvesters. The basic version (without ISOBUS licenses) costs €5,735, while the Pro version (with all required ISOBUS licenses) costs €7,435.
Dewulf reports limited demand for yield measurement systems with load cells and does not offer them factory-fitted, instead directing interested customers to Vantage Agrometius. Most yield measurement systems use an angle sensor on the machine and/or the bunker conveyor belt to compensate for work performed at an angle.
Vervaet: the only manufacturer for sugar beet harvesters
Vervaet is currently the only European manufacturer of sugar beet harvesters to actively offer yield measurement systems with load cells. This in-house developed system is available for the Q-series and Beet Eater Evo, where the company installs 2 load cells under the ring elevator. This costs €6,814 when used with an existing GPS system.
As part of the Interreg project ADaM & PreCiLa, the company is researching the effectiveness of weighing combined with camera imaging. Holmer, however, believes that varying amounts of debris have too significant an impact on the reliability of weighing and therefore does not recommend such systems. Nevertheless, some users have had them installed independently. Holmer uses ultrasonic sensors in the bunker filling automation to provide a reliable estimate of bunker content, primarily for logistics purposes, though it is less suitable for in-transit unloading. Similarly, Ropa does not supply yield measurement systems for either sugar beet or potato harvesters but does offer bunker weighing systems, mainly for logistics and to prevent overloading during transport.
In all systems with load cells, operators can input an estimated debris percentage for each field to approximate the net yield. Thanks to wireless communication, USB sticks for data transfer are no longer necessary. All providers offer the ability to send yield data wirelessly to an online cloud platform such as AVR Connect, myGrimme, or Vervaet Connect, where it can often be exported to farm management systems for analysis and decision-making, even when multiple harvesters are used in a single field.
Providing even more (and deeper) insights
To mitigate the influence of debris on load-cell-based yield measurements, manufacturers are incorporating cameras into weighing systems or transitioning fully to camera-based solutions. At the recent InterPom trade fair in Kortrijk (Belgium), AVR introduced a yield measurement system that combines load cells with cameras. This so-called calibration measurement system uses a stereo camera to capture potato tubers in the total mass flow, providing insight into net potato yield as well as tuber sizes and grades, broken down by field zones and relative to total yield. The system is also suitable for use on storage lines.
At last year’s Agritechnica trade fair, Grimme showcased its new CropAnalyser for potato harvesters. This system uses 2D black-and-white cameras and a laser to measure debris percentage, as well as the size and shape of potato tubers, linked to the harvester’s position. Availability details are yet to be announced.
Patent dispute
The British company HarvestEye offers its own camera-based yield measurement system, patented for determining the size and shape of root crops using 3D cameras. Optimised for tuber size and grading, it currently achieves up to 95% accuracy. For derived tuber weight per grade, accuracy stands at 90%. Location-specific yield in tons is not determined. The system, priced from €5,000, is available for potatoes and onions, with sweet potatoes to be added in 2025. HarvestEye systems are already in use on over 170 machines, primarily in North America, the UK, Europe, and Australia. Dewulf reports that some British customers have had HarvestEye systems installed by their dealer.
Several British manufacturers and suppliers believe that the growing popularity of optical sorting systems may impact interest in camera-based yield measurement systems. While they serve a different purpose—sorting rather than location-specific yield measurement—optical sorting systems not only provide insight into grading but also detect diseases or damaged tubers, offering significant labor savings.
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