Fall-applied phosphorus: Will it be there in the spring?
Plants may absorb 10 to 30 percent of the applied fertilizer phosphorus within the year of application. When the soil pH is maintained at proper agronomic levels for most crops (6.0 to 6.5), much of the applied phosphorus remains in forms that plants can utilize. It may take several years to “recover” the applied phosphorus, but many research studies have shown that the apparent plant recovery of fertilizer phosphorus by long-term cropping may range from 40 to 100%.
So, fall-applied phosphorus can benefit fall crops as well as spring crops, and it will provide benefits to successive crops. The benefits depend on several factors…including the balance of phosphorus applied versus phosphorus removed in the harvested crop…and the ability to keep phosphorus in the field where it is applied for maximum plant nutrition. Evaluate the advantages of fall-applied phosphorus and be sure to include it as a viable option in your nutrient management plan.