Comparison of Rooting in Soil Parent Materials Using Undisturbed Soil Cores 1

Root explorations under oats and soybean growing in cores taken from four commonly occurring soil parent materials in Illinois were compared after 8 weeks growth. Nutrient deficiencies were minimized so that the comparison was between the physical properties of the four materials. Root growth in the silty clay, silty clay loam, and loam tills differed by small amounts and was much less in all three than in the loess parent material. The variation of root weight was significantly correlated with bulk density. The 91‐cm soil cores were taken with a hydraulically operated corer, sealed in wax and stove piping, and used as individual plots in a replicated trial. In this way intersite variation was eliminated. Cores can be used for various types of plant and soil investigations.