Loam: Soil Test & Fertilizer
Your lab already told you what the bed needs. Loam turns that into pounds of the bag you bought.
What it does
A soil test report speaks in pounds of nutrient per 1,000 square feet. A fertilizer bag speaks in percentages. Loam is the conversion between them, and it does not pretend to be an agronomist: your own lab's recommendation wins — Loam converts what the report already says into what your bed and your bag need, it does not set rates.
The bag-rate calculator is free forever at full citation quality: enter the recommendation, your bag's analysis and your area, and get pounds and ounces of that specific bag per nutrient — plus an explicit reconciliation when one product cannot hit all three targets without over-delivering one of them.
A one-time $6.99 Loam Pro purchase unlocks lime and sulfur rates (from a printed rate, a buffer pH, or soil texture), per-bed tracking, an application log, organic amendments at first-season availability, and raised-bed fill volumes. No subscription, no ads, no account, works offline.
Sources are named beside the numbers: NMSU Extension Guide H-119, the Adams-Evans and Moore-Sikora buffer methods via the Universities of Delaware and Kentucky, UMass Amherst's Soil & Plant Nutrient Testing Laboratory, University of Missouri MP0733, NC Department of Agriculture Agronomic Services, and the University of Minnesota Soil Testing Laboratory.
Free soil guides
How much lime to raise soil pH
Pounds per 1,000 sq ft by soil texture, the material CCE adjustment, the single-application cap, and the buffer-pH method.
How much fertilizer per square foot
The one division that converts a recommendation into pounds of your bag, per product, with the nitrogen cap.
How to read a soil test report
Measurements vs ratings vs recommendations, what buffer pH and CEC are for, and why it says P₂O₅ rather than P.
Target soil pH by crop
6.0–6.8 for most vegetables — and why potatoes are held acid and brassicas alkaline on purpose.
Organic fertilizer N-P-K chart
Twelve amendments with first-season nitrogen availability, and the phosphate that rides along with manures.