At this point in the growing season, yield potential becomes reality. How do your crops look? By estimating yields, you can do more than satisfy your curiosity. Sound estimates can help you prepare for harvest and make better decisions.
As you head into harvest, have an idea how your crops will yield. It can help you anticipate equipment and labor needs, manage grain storage and plan livestock feed supplies and marketing. A yield estimate at the start of harvest can help you verify your combine’s yield monitor calibration.
Corn
You can choose from among several methods to estimate corn yields. A University of Wisconsin Extension publication details options ranging from hand-harvested to ear weight to ear length.1 Mississippi State University Extension outlines a common yield calculation and addresses one of the most important variables: kernel weight. 2 Purdue University Extension provides step-by-step instructions for the Yield Component Method and further guidance on estimating kernel weight.
Kernel weight is important. It is the only subjective entry in most yield calculation equations, requiring you to predict grain fill. And that prediction is less certain the further you are from harvest. Plus, actual kernel weights for the same hybrid can vary from field to field and even within the same field.3
Soybeans
Estimating soybean yields can be more challenging and less reliable than predicting corn yields. Soybeans have a great ability to compensate for various growing conditions.4 Thus, yield estimate calculations include fewer certainties and more factors that can change between when you conduct your yield estimate and harvest. Purdue University Extension agronomists offer guidance on estimating soybean yields, along with a step-by-step calculation. Or download and print this worksheet from Michigan State University Extension.
Tips for Success
Regardless of the method you choose for estimating yields, several factors can help improve your accuracy:
- Be patient. The closer you are to harvest, the more accurate your results.
- Measure carefully. Most methods require counting or selecting plants or ears for a specific length of row. An extra plant or two can skew results.
- Be representative. Average samples from several locations across the field to ensure a representative estimate. The more variable the field, the more sites you should consider sampling.
Calculating yield estimates can be worthwhile for many reasons. It doesn’t matter whether you rely on the results for planning, for early verification of your hard work or simply for bragging rights at the corner café. Any time you spend walking your fields, checking plants and measuring results is time well spent.
RESOURCES
1Lauer J. Methods for Calculating Corn Yield. University of Wisconsin Extension website. http://corn.agronomy.wisc.edu/WCM/W095.aspx. Accessed August 21, 2015.
2Larson E. How Can I Estimate Corn Yield? Mississippi State University Extension website. http://www.mississippi-crops.com/2015/07/24/how-can-i-estimate-corn-yield/. Accessed August 21, 2015.
3Nielsen B. Estimating Corn Grain Yield Prior to Harvest. Purdue University Cooperative Extension Service website. https://www.agry.purdue.edu/ext/corn/news/timeless/YldEstMethod.html. Accessed August 21, 2015.
4Casteel S. Estimating Soybean Yields — Simplified. Purdue University Cooperative Extension Service website.https://www.agry.purdue.edu/ext/soybean/News/2012/2012_0814SOYSimplifiedYieldEstimates.pdf. Accessed August 21, 2015.
