Carl Hahn, CCA, TSP, Nutrient Management Specialist
In today’s current economic and environmental climate, it’s even more important for growers to make sure that they are putting every nutrient where it belongs and maximizing every nutrient that’s applied. Most growers are familiar with spreading their phosphorus and potassium fertilizers using variable-rate technology (VRT). However, what some growers may not be aware of is that Insight FS has the capability to easily produce variable-rate nitrogen (VRN) and seeding prescriptions for your fields as well.
VRN
Do you have yield data that you have shared with your local Insight FS team member in the past or possibly sitting on your computer or monitor at home and want to take your crop management to the next level? Your local NextGenAg Specialist can take that information and use it as a powerful tool to maximize the efficiency of your fertilizer inputs.
We all know of fields where the yield can swing widely, sometimes as much as 100 bushels/acre, because of wet holes, gravel knolls, etc. Those areas that don’t produce don’t need the same amount of nitrogen that our high yielding areas do. The VRN recommendation process is built around reprioritizing where we spread our nitrogen and how much we spread. The first step is taking as many years as possible of quality yield data (corn, soybeans, wheat) that are available to us and then running those layers of data through a Multi-Year Yield Analysis Tool. This tool creates a normalized yield layer that can be used to develop the VRN recommendation. The more years of yield data we have the more accurate the prescription will be.
Figure 1. 2020 corn yield (left) vs. the VRN as-applied (right). Urea (46-0-0) was used as the nitrogen source for this prescription and was adjusted so it could be split applied. 60% of the VRN recommendation was applied pre-plant in the spring and the remaining 40% was applied by a high-clearance spinner spreader at around the V5 growth stage.
Figure 2. 2020 corn yield (left) after a season of VRN applications vs. 2019 corn yield (right) after single rate nitrogen applications. Not only was yield higher on average in 2020, but total average nitrogen used was the same or less than in 2019.VRS
That same yield data and analysis process that we can use to create VRN recommendations can be used to make variable-rate seeding (VRS) prescriptions for your planter. The determining factors for VRS are the same as what you would use for any VRT. Your fields are variable and most likely have areas where yield is higher and lower. Increasing the rate of corn seed in high yielding areas and decreasing it in low producing areas (soybean seed prescriptions are created in the opposite fashion where high yielding areas = lower populations and low yield areas = higher population) can help you get every bushel of yield from your fields. Your local Insight FS Crop Specialist can recommend the right hybrid and variety in these high and low population acres to make sure the VRS prescriptions are being utilized to their fullest.
As previously stated, the VRS service is available for both corn and soybean seed. After we run your historical yield data through the Multi-Year Yield Analysis Tool, we can obtain our normalized yield layer. The seeding rates (high, medium, low, and however many in between is desired) are customized through discussion between the Grower, Crop Specialist, and NextGenAg Specialist. These are assigned to the normalized yield zones and exported according to the make and model of the planter monitor.In some cases, VRS files can be sent electronically right to the grower’s planter.
Figure 3. Yield (left) vs. seeding rate (right). Yield distribution overlays the VRS prescription zones that were used to plant this field almost perfectly.