Starter Fertilizer Response by Planting Date Corn Study

Key Points

Objective: The purpose of this study is to monitor the performance of starter fertilizer at various planting dates.
Fertilizer Cost: The cost of fertilizer can impact overall ROI, and caused negative losses in most previous year studies. In 2025, the program was reduced to a single in-furrow product resulting in a much leaner cost, allowing postive net returns.
Colder Planting Dates: Our highest yield gain using starter fertilizer was 14.1 Bu/A. Generally, we have seen our starter fertilizer program yield the best results when used during colder planting dates.

Does starter fertilizer respond differently at earlier or later planting dates?

When it comes to fertilizer, it’s easy to overspend your dollars on nutrients and not have what you need to cover both a full fall program dry fertilizer and a starter fertilizer at the time of planting.

The goal of any fertilizer program is to create a healthier root system to get a healthier plant which results in a higher yield. However, if the cost of your fertilizer program outpaces your projected revenue, you could end up with a negative return on investment. With so many factors and fertilizer options, it’s important to analyze the potential ROI before you invest your dollars.

In this study at the PTI Farm, we are exploring how planting dates affect the ROI of utilizing a starter fertilizer. We evaluated five planting dates with and without a starter fertilizer, monitoring performance throughout the planting season. Below is the starter fertilizer program used for this study:

Product	Fertilizer Analysis	Placement of Fertilizer
6 Gal/A Nachurs® Triple Option®	4-13-17-1S	FurrowJet Wings

Study Results

In our multi-year data, we found that starter fertilizer hasn't always led to economic increases, with ongoing hikes in fertilizer prices being a main contributor. In 2025, we made a change to our starter fertilizer program, reducing it to a single in-furrow product that resulted in a much leaner cost. Along with our standard fertilizer, positive economic returns were easier to achieve. Planting dates in April and May achieved yield gains from starter fertilizer of +5.8 to +8.6 Bu/A. Positive economic net returns of +$26.16/A to +$37.73/A were seen on starter fertilizer applications on all planting dates.

2025 Corn Starter Fertilizer Response by Planting Date chart showing yield and net return values

The primary takeaway from this study so far is to consider how a starter fertilizer program can benefit your early planting dates, especially once we see fertilizer return to a more normal cost. We wouldn’t recommend abandoning your fall fertilizer applications, but instead to consider splitting your dollars on nutrients between a fall fertilizer and starter fertilizer program together.

Past Study Results

While our highest yield gain using starter fertilizer was 14.1 Bu/A in 2021, most years have seen economic losses. These disappointing revenue losses are the result of the ongoing high cost of fertilizer.

In general, we have seen our starter fertilizer program yield the best results when used during colder planting dates.