Three 150-g soil samples were extracted with 95% ethanol for 24 h in a Soxhlet apparatus. The extracted soil samples were then combined and the remaining solvent allowed to completely evaporate. Ten alfalfa seeds were planted 0.7 em deep in approximately 30 g each of extracted (13 samples), unextracted (14 samples), and potting soils (7 samples).
The soil in each pot was saturated with distilled water, the pots covered with plastic wrap, and then placed in a growth
chamber at 25°C. The number of emerged seedlings were counted at 24-h intervals for 3 d. The seedlings were re- moved from the soil and their lengths (shoot plus root) measured after 3 d.