By Wade Barnes, Founder of Ronin Agronomy & Farmers Edge
Back in 2004, when we started working with variable rate fertility, it wasn’t easy. The equipment was expensive, the software was clunky, and you practically needed an engineering degree to make it all work. But we pushed forward — because we believed that managing nutrients by zone, not by field average, was the future.
Today, that future is finally accessible. Most farms already run VRT-ready equipment. What’s often missing is the data — the real-time insight needed to make those tools pay. That’s where intense soil sampling changes everything.
The Cost of Guessing on Fertility
Even now, many growers still apply fertilizer using a single flat rate across entire fields. It’s simple, sure — but it’s still a guess. And when you guess wrong, it costs you.
Let’s take a typical 5,000-acre rotation:
- 40% canola (2,000 acres)
- 40% wheat (2,000 acres)
- 20% pulses (1,000 acres)
Pulses don’t need nitrogen — in fact, they fix it. But wheat and canola are heavy users.
Undershoot by 10 lbs of N on the 4,000 N-hungry acres:
- Canola: 2,000 acres × 3 bu × $14 = $84,000 lost
- Wheat: 2,000 acres × 4 bu × $9 = $72,000 lost
Total lost revenue: $156,000 — from just 10 lbs/acre under-applied.
Overshoot by 15 lbs of N across those same acres, at $0.75/lb:
- 4,000 acres × 15 lbs × $0.75 = $45,000 in wasted input.
Whether it’s too little or too much — the cost of not knowing is real.
Soil Isn’t Static — and That’s the Point
Even if you nailed your fertility last year, this year’s numbers are probably off. Why? Because nitrogen availability constantly shifts. It depends on:
- Temperature and moisture
- Soil organic matter and biological activity
- Leaching from rainfall
- Denitrification in wet zones
- Tie-up in residue-heavy areas
Every field, every season — it changes. That’s why sampling by zone, not by field average, is essential. It gives you current, location-specific insights that guide smarter fertility decisions.
Residual Nutrient Trends We’re Seeing This Year
At Ronin, we’ve seen major swings in residual nitrogen this year — and it reinforces why intense soil sampling pays.
- In drought-impacted areas of Saskatchewan, residual N is unusually high. With years of underperforming crops, unused N has built up in the soil.
- In Manitoba, canola yields were hit hard by heat stress. Now, many of those fields show elevated N levels — fertilizer that didn’t get used.
- Wheat fields, on the other hand, yielded big. In many cases, residual nitrogen is at rock-bottom — because the crop used it all.
- Hail-damaged fields are unpredictable. Some zones are depleted, others overloaded — no clear pattern, just variability.
Layer that over the normal zone-to-zone differences in every field, and the message is clear: you can’t guess your way to the right rate.
Precision Drives Uniformity — And Better Harvests
Precision fertility does more than increase yield — it improves uniformity.
When zones are dialed in, crops emerge evenly and mature consistently. That leads to:
- Less lodging
- Less green at harvest
- Faster, smoother harvesting
It also reduces stress on your crew and equipment — which matters when you’re pushing million-dollar machines through narrow weather windows.
An uneven crop slows you down, burns more fuel, and creates bottlenecks. Uniformity saves time, reduces wear, and boosts overall efficiency when it matters most.
What’s Next: Turning Insight Into In-Season Action
So you’ve got the tools. You’ve got the data. But what happens if you realize — mid-season — that you may have under-fertilized?
In Part 2, we’ll cover:
- How to spot under-fertilization early
- In-season sampling and tissue testing
- Top-dressing strategies for canola and cereals
- Turning efficiency into incentives — with $30/acre programs
- How to use this year’s data to plan for next