In times of volatile market prices, many growers often adjust fertilizer programs to reduce production costs and protect profit margin.

However, new soil testing conducted by DuPont Pioneer suggests that a significant number of Iowa acres may not be in the optimal range for important nutrients — including phosphorus (P) and potassium (K) — which puts yields and quality at risk.

Pioneer conducted soil tests on more than 2,000 Iowa fields in 2016 with the goal of assessing how many were in optimum or better condition for P and K fertility.

The trials were conducted as part of the Pioneer GrowingPoint agronomy program, which conducts thousands of on-farm trials each year to improve...