The researchers studied soil properties at US Climate Reference Network sites to understand soil moisture variability. They analyzed soil core samples to determine particle size distribution, soil texture, bulk density, and soil moisture content. The study found that soil properties varied significantly with depth and location within and among sites. Sand, silt, and clay contents varied more with depth than location. Silt content decreased, clay increased, and sand varied randomly with depth. Field capacity and wilting point values were consistent among pits, while bulk density showed less consistency.