Effect of fertilization on biomass and nutrient content of fine roots in a beech-birch-maple stand

Summary

Quantitative samples of fine roots (d≤3 mm) were extracted from the soil of a 90-year-old beech-birch-maple stand that had been previously treated with lime (1120 kg/ha) or lime plus 15-10-10 NPK fertilizer (6720 kg/ha). Estimates of fine root biomass were: 1246±94 g/m², control; 1229±194 g/m², lime only; and 2711±423 g/m², lime+NPK. Increased root concentration in the fertilized plot was greatest in upper soil horizons, but extended through the profile to all but the C horizon. Concentrations of N, P, Ca, and Mg in the roots were increased significantly by fertilizer treatment; K concentration was unaffected. Elements not added in the fertilizer or lime-Al, Fe, Mn, Zn, and Cu-also increased in concentration in roots from the fertilized plot. Increased root biomass, nutrient content, and rooting depth resulting from fertilization should lead to: (1) a higher organic matter and nutrient content of the deeper soil horizons, (2) availability of a larger volume of soil —with its moisture and nutrients—to the vegetation, and (3) increased wind-firmness in addition to the more direct effects of fertilization upon growth, vigor, and soil properties. re]19730806