The deduction is only as good as the science under it. A proper study measures the unexhausted fertility in the exact ground you bought, at the right time, and values it in a way that holds up.
Start With a Soil ReviewThere’s no rule-of-thumb per-acre figure that survives scrutiny. The deduction is built from parcel-specific soil samples, analyzed for the nutrients and amendments that represent unexhausted fertilizer, and compared against a normal baseline. What’s left, the measurable excess tied to prior fertilization, is what supports the deduction. Everything downstream depends on getting this right.
Wait too long, or fertilize first, and the evidence of the prior owner’s unexhausted fertilizer is diluted or gone. This is the single most common reason a claim can’t be supported.
The core of most residual-fertility value on cropland.
Applied soil conditioners that persist and deplete over time.
Where supported, the applied nutrients above baseline.
Each is measured against a normal baseline for the crop and region, only the unexhausted, applied excess supports the deduction.
Only if they’re parcel-specific and taken in the year of purchase before any new fertilizer. Routine agronomic tests from later, or from a different field, generally won’t support the deduction.
It complicates matters, once you fertilize, separating the prior owner’s unexhausted fertilizer from yours is far harder. The sooner we sample after closing, the stronger the claim.
Qualified agronomic testing tied to a defensible methodology. The point is parcel-specific, lab-verified data, not estimates.
From the measured excess fertility and its supportable cost, not a flat per-acre number. The tests drive the figure.
This page is general information, not tax or legal advice. The residual fertility deduction under Section 180 is fact-specific and rests on limited authority; it requires parcel-specific soil testing, and aggressive or unsupported claims carry audit risk. Eligibility and amounts are determined through the soil study in coordination with your tax advisor. Novaric does not guarantee deduction amounts or any IRS outcome.