Soils of an association may vary in productivity and fertility response because of differences in landscape positions, hydrologic properties, and capacity to retain and release nutrients. These differences may in turn affect the validity of fertilizer recommendations based on soil testing programs. The yield pattern of alfalfa was studied over three years in Gilpin, Ernest, Brinkerton soils of an association developed in residium and colluvium from sandstone and shale parent material (from Brookville, Jefferson County, Pennsylvania), and in the Cambridge ‐ Venango — Frenchtown soils of an association developed in sandstone and shale glacial till (from Meadville, Crawford county, Pennsylvania). Soil test recommendations for F and ? were compared with yield response of alfalfa to increasing application of the respective nutrients (0, 45 and 90 kg P.ha‐1, and 0, 175, 350 and 525 kg K.ha‐1) in each of the six soils.