The 2025 Agricenter corn trials closed out with three replicated comparisons across N rates and timing. Headline first, then the caveats.
The number
Across the three comparison sets:
- Pro-Cal + Nitro-Maxx+ + 3-18-18+ stack: average yield +18 bu/ac vs. the 200-50-100 dry control. N=4 plots, range +12 to +24.
- Nitro-Maxx+ alone (no P-K stack): average +9 bu/ac vs. control. N=4, range +5 to +14.
- Pro-Cal alone (calcium correction only): average +4 bu/ac vs. control. N=4, range +2 to +7.
The take-home: the stack is doing more than the sum of its parts. Calcium fixes base saturation, the slow-release N keeps feeding past V12, and the placed P-K gives the root system something to grow into early.
The caveats
A single year, a single site, four plots per treatment. This is directional evidence — strong enough to recommend the stack on similar soils, not strong enough to claim a guaranteed result on your farm. Strip-trial it before you scale it.
Specifically:
- Trial soils were CEC 18-22 with starting base sat 58% Ca. Lower-CEC sandier soils may not respond the same way to the Pro-Cal layer.
- We had average rainfall in May-June. A drier early season would have hurt the placed P-K plots more than the dry-broadcast control.
- These were not no-till. No-till residue management changes the timing math.
What we’d do with this on your farm
If your soil test shows Ca base sat under 65% and CEC over 15, we’d run the full stack with a +/- N-rate strip and ask your yield monitor to settle it for next year. The data above is enough to justify the test, not enough to ship the whole farm.
We’ll add 2026 reads here as they close out.
— AgriTec Agronomy