Soybean Root Anatomy as Influenced by Soil Bulk Density¹

This research was conducted under controlled greenhouse conditions to investigate the effects of soil compaction on soybean ( Glycine max L.) root antomy. Previous research has shown that high soil compaction reduces root efficiency in moving air, water, and nutrients into the plant. Increasing bulk density from 1.65 to 1.95 g/cm 3 altered the root anatomy. In the high density soil layers a larger percentage of the root volume was occupied by cell wall material, and the transverse sections of the roots had a wavy outline with ruptured epidermal cells. The vascular cylinder became more oval with a gradual increase in both casparian thickening in the endodermis and wall thickening in the xylem vessels.