How Do I Choose the Right Variable Rate Program?

Chris Hawkins
Director of Sales – Farmer Services

In agriculture today where risk is high and profit margins can become quite thin, variable rate (VR) application programs have emerged as indispensable tools. They allow farmers to optimize input use, enhance crop yields, and maximize profitability, while at the same time minimizing environmental impact. However, with many VR programs and service providers available, farmers face the challenge of selecting the right system for their unique needs.

Here are some essential factors that farmers should consider before deciding on a VR program and service provider:

1. Establish Your Objective: There are many reasons why farmers utilize VR application. Increased yield, better pesticide application timing, and improved harvestability are just a few. Decide what problem you are attempting to solve with VR on your farm and find a service provider who will work with you to accomplish that.

2. Hardware Compatibility: Of course, you will need to make sure your own equipment is capable of, and ready to, apply VR prescriptions. Check with your equipment dealer on that. If it is “ready”, make sure your service provider can write prescriptions that will be compatible with your hardware because prescription files often need to be written specifically to match various types of controllers.

3. Field Variability (Zones): Many factors can influence variability within a field, and we have tools today to make field zone maps based on ALL of those factors at once (ie. satellite imagery, yield monitors, etc). Generally, these are a good view of “what” variability exists at a specific time (both spatial and temporal variability). However, great VR programs build zone maps based primarily on spatial factors such as soil, water dynamics, and topography (see figure 1). These stable characteristics are an ideal foundation for understanding “why” variability exists in any season.

Figure 1. SWAT MAP built primarily from spatial field characteristics.

    4. Ground Truthing and Zone Sampling: Make sure your service provider incorporates ground truthing when building the zone maps for your VR program. Ground truthing is the process of comparing what an agronomist sees in a field with their own eyes to the field data that was collected. In this way, the most accurate map possible is chosen as a template for soil sampling. A proper variable rate program includes soil analysis from the same points each year by zone so the agronomist can make precise recommendations based on nutrient changes from year to year.

    5. Scalability: Consider whether the VR service provider can scale with your operation as it grows. The best service providers are innovative and grow with you as they develop and incorporate new technology into their existing programs making their clients even more profitable. In figure 2 below you can see just one example of such technology. SWAT CAM can help to significantly reduce pesticide costs.

    Figure 2. SWAT CAM crop and weed imaging system. Photo: Croptimistic Technology Inc.

    6. Ease of Use: Development of a good variable rate program can be quite complex, however for the farmer, it should be relatively easy to use. The service provider should handle the complexity so you can focus on other aspects of your farm.

    7. Support and Training: Assess the level of support and training provided by the service provider to ensure successful implementation and troubleshooting. Support should be accessible especially in the peak seasons of work. The company should have both live people to speak with as well as online support.

    Figure 3. SWAT SUPPORT portal for learning and support.


    8. Cost/Benefit: When analysing cost/benefit of a variable rate program, look beyond just one year. Sometimes the upfront cost of VR systems may be higher in the first year, but significantly lower in the following years. Further to that, Return on Investment (ROI) is tricky to measure because it is farm specific. It's easy to look at yield alone because that's tangible. However, yield is influenced by many different factors so it should not be the sole measuring stick for the value of a VR program. There are other intrinsic benefits to consider, such as operational efficiency and grain quality. It's very difficult to measure the value of spraying your fungicide at just the right time, or minimizing lodging, but the value needs to be acknowledged.

    9. Reputation: Look for a system that offers high accuracy and precision in data collection, analysis, and application. Research the reputation and track record of the service provider, including their experience in the precision agriculture industry. Seek recommendations from other farmers or agricultural professionals to gain insights into their experiences with the system and service provider.

    10. Regulatory Compliance: Ensure the program complies with local regulations regarding pesticide and fertilizer application, data privacy, and environmental concerns.

      In conclusion, choosing the right variable rate program and service provider is an important decision that can significantly impact the success of your farm. By carefully considering factors such as map development and soil sampling process, scalability, ease of use, support and training, cost/benefit, reputation, and regulatory compliance, you can make informed choices that align with your goals and objectives.

      If you would like to learn more about our VR program which uses SWAT MAPS technology, or any of our new innovations (such as SWAT CAM), please connect with us at sales@swatmaps.com. Or you can find more information on our website at SWATMAPS.com.

      High resolution plant stand assessments with SWAT CAM

      Brandon Smith
      Regional Manager, Central SK
      brandon@swatmaps.com

      Having a consistent and even plant stand across a field is beneficial in achieving even maturity and maximizing yield. Consistent maturity is critical for fungicide staging (especially for fusarium head blight in wheat) as well as harvest timing. At Croptimistic we use SWAT MAPS to not only vary rates of fertilizer but also to vary seeding rates. This allows us to have a nice, even plant stand. Conditions in the defined SWAT zones will affect seedling mortalities, therefore we can increase seeding rates in those zones to even out plant stands (Figure 1). Typically, zones 1-2 and zones 9-10 will have the highest mortality depending on the field’s soil properties and moisture conditions. These zones will have the highest seeding rates. Zones 1-2 are drier areas of the field that are water-shedding and can often have lighter textured soil, tend to have shallower seeding, and can dry out when it is hot and windy, which increases mortality. Zones 8-10 can often be “mudded in” as these areas are wet when seeding, can have permanent soil issues such as salinity, peat, or sodicity, and these factors again, will increase seed mortality. In the end, we typically prescribe the same amount of seed as we would for a flat rate, but  redistribute it to optimize the final plant stand.

      Figure 1: Example of VR canola, wheat, and pea seed prescriptions from left to right. Increasing the seeding rates in Zones 1-2 and 8-10, as these zones have higher mortality.

      It is important that we assess our VR seeding rate strategies to ensure that we are hitting our plant stand targets across SWAT zones. Before SWAT CAM, the process for doing this was by manual plant stand counts, which involved counting a few different areas in each zone to come up with an average plant stand count across zones and across the field. This method was very labor intensive and low resolution, since we are counting limited locations in a few fields across a farm to assess our VR seed strategy. As we know, different fields will have different seeding conditions, soil types, and therefore different mortalities. Manual plant stand counts are not able to capture all variability within every SWAT zone across a farm.

      Figure 2: SWAT CAM system mounted to sprayer boom

      SWAT CAM is a camera system that is mounted to a sprayer that is automatically capturing 1000s of images on every field, running those images through a machine learning algorithm, and getting plant stand counts for several crops. As of today, SWAT CAM can count individual plants in canola, corn, soybean, dry bean, faba bean, and potato. In 2024 we will be beta testing plant stand counts for cereals and lentils.

      Figure 3: Example of SWAT CAM image with canola plant stand count model.

      SWAT CAM allows us to accurately assess our VR seed strategies on the crops that we have plant count models for. As shown in Figure 3, we can count individual canola plants and calculate the average plants per square foot in that image; in this example the average was 5.5 plants per square foot. The seeding rate in this zone was 4.3 lbs/ac and calculated mortality was 44%, which is slightly better than the industry standard for canola seed.

      Figure 4: Canola plant stand count by zone with calculated mortalities.

      With 1000s of counts across the field analyzed by SWAT zone we can then get an average of the whole field and an average plant stand for each SWAT zone. This data can help us to adjust our VR strategies. For example, if SWAT zone 1 has a higher plant stand than we were expecting, and zone 1 received the highest seeding rate, then in the future we can consider decreasing the seeding rate resulting in reduced seed costs. Another example may be that certain fields on the farm tend to have lower mortality across the whole field and the plant stand is always higher on those fields. This is another opportunity to decrease the seeding rate. Alternatively, fields with higher-than-expected mortality should be investigated further. Do seeding rates need to increase or are there other factors causing the high mortality that need to be altered, such as residue management, fertilizer placement and seed-placed rates?

      SWAT CAM data allows us to calculate mortalities across SWAT zones by comparing the seed rates applied to the actual plant counts calculated by SWAT CAM. Automation of this process allows us to capture optimized plant stand counts across full farms at a low cost. SWAT CAM increases our confidence in our plant counts such that we can make better decisions and adjustments to variable rate seed strategies.