The liming of soils is an important part of the overall fertility program for soybean production. Whether or not liming is needed is generally based on the soil pH. Soybeans are adversely affected by acidity when the pH falls below about 5.8. Considerable interest about soil pH specific management recommendations exists in Iowa. Since soil pH varies across Iowa, it is likely that the current optimum plant population for soybean needs to be adjusted depending on soil pH. The objective of this study is to identify the optimum plant population for soybean at different soil pH readings.