Minnesota study says it can
Applying 90 lbs/acre of phosphate fertilizer boosted soybean yields 5 1/2 bu/acre in a 2002 University of Minnesota-Crookston farm study. Russ Severson, U of M-Crookston regional extension educator, conducted the study.
Previous research on phosphorus fertilization for soybeans in northwestern Minnesota had not shown a positive yield response. However, new soybean varieties with higher yield potentials have been developed for the region over the past ten years.
The 2002 study took place at the Ron Peterson farm northeast of Crookston. The soil was a Ulen loamy fine sand with an Olsen phosphorus level of seven parts per million. Rates of 0, 15, 30, 45, 60, 75 and 90 lbs of phosphate fertilizer were applied before planting. Legend 009 was seeded in 22"rows.
"Soybean yields increased from 37.6 bu/acre with no added phosphorus to 43.1 bu/acre with the addition of 90 lbs of phosphate," Severson reports. "Protein concentration increased from 31.8% with no added phosphorus to 33.8% with the addition of 90 lbs of phosphate."
Additional trials are needed on other varieties and soil test levels to confirm the need for phosphorus fertilization to increase soybean yields and protein levels, Severson says.