| Popis: |
Biomass and nutrient removal and redistribution were estimated for combinations of two levels of harvest utilization (stem-only vs. complete tree) and two methods of site preparation (chop/broadcast burn vs. shear-pile/disk) in the Piedmont of North Carolina. Stem-only harvest removed 57 kg ha −1 N, 5 kg ha −1 P, 35 kg ha −1 K, 52 kg ha −1 Ca and 14 kg ha −1 Mg. Complete-tree harvest increased N, P, K, Ca and Mg removal over stem-only harvest by 216, 304, 152, 254 and 151%, respectively, although biomass removal was increased by only 65%. Estimated displacement of N and P into windrows during site preparation depended on harvest utilization, but generally exceeded harvest removals by at least 200%. Nutrient losses resulting from broadcast burning were small, primarily due to ineffectual burns. Removals, displacements and/or losses of nutrients during harvest and intensive site preparation were equal for both harvest utilization levels. These amounted to 714 kg ha −1 of total N in biomass and soil, and 46, 154, 481 and 88 kg ha −1 of P, K, Ca and Mg, respectively, in biomass and Mehlich III soil extractions. |
