The Pitfalls of Inaccurate Harvest Yield Data
Jennie Dvorak | August 31, 2017
Your yield data may come from your combine, grain cart, or from truck scales, but each has shortcomings that may impact your farm decisions.
This harvest, growers will spend significant time and money trying to get accurate yield data from combine yield monitors, grain carts and/or truck scale tickets. However, each of these sources has varying degrees of accuracy, depending on how well they are calibrated and maintained. Your source of yield data and how well it’s maintained can play a major factor in your farm decisions.
So how do you know that your yield numbers are accurate? We will discuss three sources of yield data, their shortcomings, and what implications inaccuracy can have on your decisions.
The Three Sources of Yield Data
You may decide to invest in a truck scale system for your bin site, a grain cart sensor to measure moisture and weight, or a yield monitoring system for your combine. How accurate are these sources of data, on average?
Truck Scale Data
If calibrated and maintained, truck scales have the lowest error. However, these scales are often far from the field and require someone to attribute the load to the right farm and field, possibly on a paper ticket that needs to find its way back to the office. Lost or misattributed loads could significantly contribute to yield error. This often leads to significant investment in tools and time to measure yield closer to the field, potentially slowing down harvest operations. One missed load on a 100 ac field can lead to error of 0.5% (assuming 180 bu/ac corn and a load is 1000bu).
Grain Cart Data
You might be using grain cart or combine data to track yield. The data you get from grain carts is only as good as your calibration with truck scale weight. If calibrated correctly, manufacturers such as Digistar and Avery Weigh-Tronix state that the data should be within 0.1% to 1% accuracy of your scale weight. But grain cart measurements typically are burdensome for an already busy grain cart operator, and don’t factor in moisture reliably, leading to another source of error.
Like grain carts, your yield monitor data is only as good as its calibration with grain carts or scale weights. Our customers tell us their yields reported by the combine are 5-10% off. Only a handful of our customers use combines as a source of truth today. Any miscalibration in any of these can lead to more than a 10% error in your yield data.
Farm Financial Implications
Knowing the accuracy of your yield data is one thing, but knowing the implications of inaccuracies is another, especially for crop insurance and the perceived financial implications.
Crop Insurance Premiums
If you can track and submit digital harvest data, your crop insurer has more insight your crop production risk and your farming practices, which can help the insurer to better underwrite and price your risk (i.e. your premium).
However, don’t forget that if you submit data using precision Ag harvesters, you will be required to prove that your harvester and grain cart are calibrated within 3% of scale weight. If you do not, then you are subject to the same rules as those growers who do not use precision technology, which means that you’re required to submit proof of your actual production (which is a lot of work!). Additionally, for any yield error you encounter, you will also have to update your crop insurance records.
Topline / Margin Analysis
We developed a simple table to illustrate the ramifications of a 0.1%, 1% and 10% yield error for corn and soybeans on your top line.
If you use your combine as your only source of harvest data, for example, and your combine was off by 10%, you could potentially have 10% more or less of your perceived inventory. Assuming that you harvest 180 bu/ac corn, you could have up to 18 bu/ac more or less in your inventory. Now let’s say you planted 1,000 acres of corn at a price of $3.50/bu, a 10% error in yield means you can misrepresent $63,000 on your bottom line.
You will probably not lose $63,000 from this mistake, but think of the impact to your field level decisions, crop inventory, and grain marketing. Here are a couple of examples:
- On a field with small margins and a high yield error, you can make a different decision on what crop to grow, or not grow. Growing a less productive crop based on inaccurate data has financial ramifications and can cost you tens-of-thousands of dollars each year.
- For grain marketing, a high yield error might cause you to over or under contract your inventory.
- Land rental renegotiations are coming up shortly, imagine having to explain a 10% error on your crop share. This might not have any financial implications, but can damage your credibility with your landlord.
Mistakes with yield data can impair your ability to make accurate farm decisions and can harm existing relationships with buyers and landlords.
Get Your Yield Data Right
It takes a lot of time and money to invest in the right tools and technology to track accurate yield data. Whether you get your yield data from your harvester, grain carts, or truck scales, we know how important your yield data is to your farm decisions. We’ve created a FMS platform to help you reconcile and understand your yield from all data sources to improve your grasp on your farm’s bottom line.
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