Technical Abstract: Proper placement of fertilizer nutrients in soil is just as important as choosing the correct amount to apply. Optimum placement of added nutrients improves utilization by the crop root system, which sets the stage for maximum yields. Due to the complexity of the plant-soil system, the most effective placement will vary with the type of nutrient(s) applied, the crop being grown, and the environment in which the crop is grown. During six years of field trials, we found that at least some of the phosphorus (P) and potassium (K) in liquid fertilizers applied on the soil surface two inches to the side of the corn row at the time of planting moved two to four inches into the soil. These higher levels of plant-available P and K in the root zone could benefit the corn plant throughout the remainder of the growing season. In a separate field study comparing liquid swine manure application with knife injection and a low-disturbance injection system, manure application increased available soil P in the four to six inch soil layer following knife injection, while the highest P levels were detected in the two to four inch layer following low-disturbance injection. Our results suggest that low-disturbance injection of swine manure can minimize losses of P to surface runoff, while providing optimum P availability to a subsequent agronomic crop. The purpose of this presentation is to provide a brief overview of factors affecting soil supply of P and K, and to discuss the relationship of these soil processes with P and K placement.