The Effects of Long-Term Phosphorus Restriction on Soil Health and Phosphorus Availability.

Phosphorus (P) fertilizer recommendations seek to develop a balanced P budget for cropping systems. Oftentimes, this results in P rate recommendations that are lower than rates generally applied by growers. This decrease in applied P fertilizer is generally thought to decrease P losses to the environment and improve environmental quality. However, the long-term effects of decreased P fertilization on soil health and quality have not been examined. This study examines the effects of 11 years of P fertilization—at 0x, 1x and 3x grain removal—on a suite of soil health indicators across Ohio’s primary agricultural land resource areas. Additionally, the effects of these long-term fertilization rates on the availability of inorganic and organic P fractions will be evaluated. The inter-relationships between soil health, P fractions, and soil mineral composition will be investigated to explore causal mechanisms.