The increase in farm machinery weight in the recent decades has increased the likelihood of progressive soil compaction compromising soil productivity and environmental quality. Cover crops with strong root systems may help alleviate soil compaction effects during fall-winter fallow periods. We evaluated compaction-alleviating ability of four cover crops in a typical Illinois Drummer series: very deep, poorly drained soil formed in loess or other silt materials. The cover crops used were: rye (Secale cereale L.), triticale (Triticosecale cv Presto), buckwheat (Fagopyrum esculentum), and hairy vetch (Vicia villosa Roth) mixed with “groundhog radish” (Raphanus sativus) and “groundhog radish” sown alone after four compaction induced treatments in September 2010. The compaction treatments included no compaction (control), Small tractor, Large tractor and a Hauling truck. Soil parameters such as, bulk density, penetration resistance and water aggregate stability were measured before and after the compaction treatments, and before soybean planting.  Soil properties and crop physiology parameters results will be shown.