Each year, an increasing number of farmers are utilizing planters with variable-rate seeding (VRS) capability, and more farmers report putting this feature to work to vary corn and soybean seeding rates. Those using the technology expect it to help increase yields as well as maximize the value of their seed investment.
The growing number of VRS-enabled planters and widespread on-farm use of GPS technology make it easier than ever to deploy a VRS strategy. However, growers still need to understand the variability within their fields and implement the appropriate hybrid-specific seeding rates. This Crop Insights discusses guidelines for developing a VRS strategy, designating management zones, selecting seeding rates, and implementing a field prescription.
Figure 1. Decision Zones incorporate a field’s historical yield data and management layers to segment and improve the precision of the soil productivity zones.
Selecting a Hybrid
The next step is selecting the proper corn hybrid for the field, taking into account the range of possible growing conditions and resulting yield potential of field areas. Your local Pioneer sales professional is a valuable resource to help identify the right product for your growing environment.
Selecting Seeding Rates
Pioneer scientists conduct thousands of field research trials at hundreds of locations annually across North America to help understand grain yield response to planting rate for Pioneer® brand hybrids. In addition, many growers have their own data on variable planting rates gathered from as-planted and yield data. Decades of Pioneer research have shown that corn yield response to seeding rate within a commercially-relevant range can usually be well-described by a quadratic function. Grain yield will increase with seeding rate up to an optimum point and then decline as seeding rate is increased above the optimum due to a higher rate of barrenness and extended anthesis-silking intervals (Jeschke et al., 2009). The optimum seeding rate can vary based on hybrid genetics. Figure 2 shows an example of quadratic response functions for 2 hybrid families with the same CRM that have been shown to differ in their response to plant population in Pioneer research trials.
Figure 2. Corn yield response to plant population of 2 Pioneer brand hybrid families with similar comparative relative maturity.
Figure 3. Corn grain yield response to seeding rate at 9 yield levels, 2009-2014. Dots indicate the economic optimum seeding rate within each yield level.
Note: Economic optimum seeding rates based on a seed cost of $3.50/1,000 seeds and corn grain price of $4.00/bu.
Figure 4. Examples of variable-rate seeding prescription maps in EncircaSM Yield Stand.
Jeschke, M. 2019. Corn Seeding Rate Considerations. Crop Insights.
Doerge, T., M. Jeschke, and P Carter. 2015. Planting Outcome Effects on Corn Yield. Crop Insights. Vol 25, No. 1. Pioneer.
Jeschke, M., S. Paszkiewicz, and J. Mathesius. 2009. Corn Performance at Very High Plant Populations. Field Facts. Vol. 9, No. 15. Pioneer.
Woli, K.P., C.L. Burras, L.J. Abendroth, and R.W. Elmore. 2014. Optimizing corn seeding rates using a field’s corn suitability rating. Agron. J. 106:1523-1532.
1Agronomy Information Manager, Pioneer
2Senior Agronomy Sciences Manager, Pioneer
3Product Owner Encirca Services, Pioneer
4Senior Manager, Encirca Services, Marketing, Pioneer
The foregoing is provided for informational use only. EncircaSM services provide estimates and management suggestions based on statistical and agronomic models. Encirca services are not a substitute for sound field monitoring and management practices. Individual results may vary and are subject to a variety of factors, including weather, disease and pest pressure, soil type, and management practices. Encirca services are provided subject to the terms and conditions of purchase which are part of the purchase documents.
PIONEER® brand products are provided subject to the terms and conditions of purchase which are part of the labeling and purchase documents.