Environmental Impacts of Miscanthus x Giganteus Establishment on Soil Quality.

Miscanthus (M. x giganteus) shows promise as a leading cellulose ethanol feedstock because of its’ high cellulose production. Conventional planting methods however have a large potential for degrading soil properties and inducing elevated soil erosion rates during the establishment and development period. The objective of this study is to evaluate the effect of Miscanthus establishment with selected companion crops on soil physical properties, surface processes, and Miscanthus canopy development. Studies were conducted on 2nd year growth of Miscanthus in Central Iowa. Treatments of four companion crops included rye, oats, crimson clover, and white clover. Measured parameters included bulk density, aggregate stability, and infiltration rate. Bulk density and aggregate stability were measured once after the growing season. Saturated infiltration rate was taken monthly during the growing season. Photogrammetry of canopy cover was taken during the growing season to monitor Miscanthus canopy cover development between treatments. Wet aggregate stability mean weight diameter was largest in the white clover treatment (1.25mm) and smallest in the Miscanthus only treatment (1.08mm). Infiltration rate from July to August was highest in rye cover treatment and lowest in crimson clover. Miscanthus only plant cover increased the most from June to July, approximately 40% compared to white clover cover treatment which decreased by 15% over the same time frame. There was no statistically significant difference between cover treatments for bulk density. Miscanthus control plots had less favorable soil quality characteristics than did the plots with companion crop treatments.