🌱 CropGPT Ontario crop nutrient planner · grounded in OMAFRA Publication 811
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Fertilizer Products and Analyses

The fertilizer products commonly available to Ontario growers, with their guaranteed analyses and indicative bulk prices for budgeting.

Product analyses

ProductGradeNP₂O₅K₂OS Indicative cost
Urea46-0-046%0%0%0%$700/t
UAN solution28-0-028%0%0%0%$480/t
Ammonium sulphate21-0-0-24S21%0%0%24%$650/t
Anhydrous ammonia82-0-082%0%0%0%$1050/t
MAP11-52-011%52%0%0%$950/t
DAP18-46-018%46%0%0%$1000/t
Triple superphosphate0-46-00%46%0%0%$850/t
Single superphosphate0-16-0-12S0%16%0%12%$450/t
Potash (MOP)0-0-600%0%60%0%$650/t
Sulphate of potash0-0-50-18S0%0%50%18%$1100/t
Prices move. Treat these as editable placeholders for budgeting. Fertilizer markets swing hard with natural gas, freight and global demand — always get a current quote from your local retailer.

Buy the nutrient, not the bag

Compare products on cost per unit of nutrient, not price per tonne. Urea at $700/t carries 460 kg of N per tonne, so nitrogen costs about $1.52/kg. UAN looks cheaper per tonne but carries far less N per tonne — the comparison only makes sense after you divide.

Phosphate sources carry nitrogen too

MAP (11-52-0) and DAP (18-46-0) both supply meaningful nitrogen alongside phosphate. If you buy phosphate as MAP or DAP, that nitrogen must be credited against your N requirement or you will over-apply. The calculator solves phosphate first and subtracts the nitrogen it carries before sizing your urea or UAN.

Oxide versus elemental

Fertilizer is sold as oxides (P₂O₅, K₂O) but soil tests report elements (P, K). To convert: P = P₂O₅ × 0.4364 and K = K₂O × 0.8301. Mixing the two up is one of the most common and most expensive arithmetic errors in nutrient planning.

Related guides

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