FINE ROOT RESPONSES TO SOIL DECOMPACTION AND AMENDMENT IN RED MAPLE (\u3ci\u3eACER RUBRUM\u3c/i\u3e)

A combination treatment (AFM), designed to decompact and amend urban soils, and its individual components (air tillage, fertilizer, and mulch) were tested to determine their effects on fine root morphology. The site was an urban area located in Anderson, SC and included 50 red maples (Acer rubrum) growing in compacted, nutrient poor soils. Treatments were installed in November 2005, and data was collected through summer 2008. Data collection included minirhizotron images, soil moisture readings, soil temperature readings, and pre-dawn leaf water potentials. The AFM treatment had the lowest root production, root standing crop, and median root lifespan. The AFM treatment had the highest rate of root turnover. Median root lifespan for the AFM treatment was 248 days, followed by the mulch-only treatment which had a median root lifespan of 434 days. Median root lifespan for all other treatments exceeded 800 days. The mulched plots (AFM and mulch-only) had significantly higher soil water content and foliar leaf water potentials during periods of summer drought. Overall, the AFM treatment produced and maintained the fewest number of roots, had the highest rate of root turnover, but provided the most improvements to previously measured soil parameters as well as overall tree appearance and performance