- Potential seed cost savings
- Potential for increased yield in high yield areas
- Potential for increased yield in low yield areas
- Determine ideal populations for each field
Possible methods used to base seeding prescriptions on:
- Historic yield potential based off of yield data
- Soils map
- Electrical conductivity (if EC correlates with yield)
- Producer knowledge
The ideal seeding rate is often not the same across the field due to changes in soil texture, top-soil depth, drainage, fertility, etc. and can easily vary 10 to 15% within the field. Over the last several years, we have fine-tuned several methods for successfully changing the seeding rate to match it with yield potential. The best method depends on the factors affecting yield differences. In most cases, basing seeding rate off of historic yield potential with several (3-4 years) years of yield data is the best method. Soils maps can be used if wide ranges in soil texture are present within a field. Electrical conductivity (EC) can be used in some fields but in dryland fields often times EC does not correlate with grain yield. If EC and grain yield are correlated for a certain field then EC can be used.
Figure 3. Soybean yield of seeding rate strips across the field. These are used to create future prescription maps.Seed cost savings can be $1-5/ac depending on the variability within the field. However, the increase in yield from correctly matching yield potential with seeding rate can easily be >5%. The first step in the process is to put out replicated population strips across the field to identify the correct seeding rates to be used in the field. These strips are evaluated with yield monitor data. This needs to be done multiple years to take into account change in varieties/cultivars over time. Each year is a step towards fine-tuning the seeding rate prescription.
What you receive:
- Historic yield analysis
- Prescriptions for seeding rate based on best identified method
- Evaluation at end of the season