Researchers developed a method to estimate soil thermal conductivity using basic soil information like texture and density. They measured soil thermal conductivity in different types of soils and found that the values vary based on soil texture and moisture content. By dividing the data into sand, silt, and loam categories, they were able to create accurate pedotransfer functions for predicting soil thermal conductivity. These functions can help in various environmental studies without the need for expensive and time-consuming laboratory measurements.