The soil beneath four hog manure lagoons was samples and analyzed for NO3-N, NH4-N and soluble P. Nitrate levels were essentially zero in all samples taken shortly after the lagoons were emptied. Soluble P levels were high immediately below the lagoon but decreased to background levels within 20-30 cm. Ammonium levels were very high immediately below the lagoon. The levels decreased to background levels within 20-30 cm on two lagoons on fine-textured soils that had been in use for two years. In a medium-textured soil and a coarse-textured soil beneath older lagoons, very high levels existed to the maximum depth samples. It is suggested that this accumulation of NH4-N presents a serious hazard should the lagoon be abandoned and the soil become aerobic. Earthen manure lagoons should not be recommended on medium or coarse-textured soils.