Northern Research and Demonstration Farm
An experiment was initiated in 1994 to study phosphorus (P) fertilization rates and placement methods for corn and soybean managed with no-till or chisel-plow tillage. We measured grain yields from all plots, soil-test values for selected plots, and until 2005 nutrient removal with harvested grain for selected no-till plots. In this report we summarize long-term trends (1994 until 2005) for grain yield, P removal, and soil test P for plots managed with no-tillage.
Iowa State University
Mallarino, Antonio P. and Rueber, David, "Grain Yield, Phosphorus Removal, and Soil Phosphorus Long-Term Trends as Affected by Fertilization and Placement Methods in Corn-Soybean Rotations" (2008). Iowa State Research Farm Progress Reports. 758.