Poultry litter is a potential alternative phosphorus and potassium source for row crops, but research has not clearly established the availability of these nutrients in manures. Research was initiated to compare the influence of poultry litter (PL) and inorganic P and K fertilizers (INF) applied at equal nutrient rates on soybean tissue nutrient concentrations and yield. Pelleted PL and triple superphosphate (TSP) were applied at rates of 15, 30, 45, 60, and 75 kg P/ha. Muriate of potash was applied with TSP to supply equal K rates as PL at eight field sites from 2004-2006. Tests at four sites were contaminated uniformly with P and K from the surrounding field and only the PL treatments were evaluated statistically. All soils had medium to above optimum soil-test K levels and soil-test P ranged from very low to above optimum for soybean. Soybean yield and tissue P and K concentrations at the R2 stage were not affected by nutrient source (PPL or INF) or application rate at four sites or by PL rate at two sites contaminated with P and K fertilizers. Soybean receiving PL at the two remaining sites responded positively to PL rate. Soybean yields were increased by 13-29% by application of PL. The positive yield response to PL may be partially attributed to N in the PL as soybean receiving INF treatments showed no significant yield increase to extra P and K. Soybean at the two responsive sites followed rice in the rotation, were seeded with maturity group III or IV varieties, and planted in April or early May. All non-responsive sites were planted in late May or June and seeded with maturity group V varieties. Results provided little or no insight concerning the P and K availability of PL or equivalence to INF fertilizers for soybean. Additional studies are being conducted to evaluate these soybean management factors for their role in identifying soybean production systems that may benefit from poultry litter application.