TSP, MAP, DAP and MES all supply essential phosphorus for next year’s crop. Regardless of source, the phosphorus contained is all P2O5 and behaves the same in the soil. The major difference is the % of P2O5 contained per ton.
There is no single “best” fall broadcast phosphate — the correct choice depends on soil test P, whether you also want to deliver N/S and field erosion/leaching risk.
TSP is great where N or S aren’t needed and cost per unit P matters most. For S deficient soils, emphasize MES convenience — single granule, uniform spread. MAP is slightly more acidifying and can increase availability of P in high pH soil. This is not a major concern in Illinois where soil tends to be acidic.
| Product |
Analysis |
Nutrients |
| TSP |
0-46-0 |
P only |
| MAP |
11-52-0 |
P + N |
| DAP |
18-46-0 |
P + more N |
| MES |
12-40-0 + 10S |
P + N + S |
TSP (triple superphosphate) — high-P straight phosphate. Typical analysis ~0-46% P₂O₅; no N, no S. Good when you want maximum P per ton without added N. Tends to be the cheapest option.
MAP (monoammonium phosphate) — combination fertilizer (11-52-0). Supplies both P and a low level of N. When dissolved it tends to be slightly acidic which may help with availability on high-pH soils.
DAP (diammonium phosphate) — combination fertilizer (18-46-0). Higher in N than MAP; DAP dissolution is more alkaline near granules (can increase localized pH). Supplies more ammonium N per unit P than MAP.
MES (MicroEssentials®) — a fused, multi-nutrient granule (12-40-0 + 10% S). MES fuses N and P together and includes sulfur; sulfur is provided in two forms (sulfate = immediately plant-available, and elemental S = slow release/oxidation over time).