Potential of Paulownia elongata trees for swine waste utilization
A greenhouse experiment was done with vegetatively propagated trees to examine the influence of swine lagoon effluent on the growth and foliar nutrient content of the fast-growing hardwood species Paulownia elongata. Application of swine lagoon effluent promoted plant growth and was as beneficial as a complete chemical fertilizer applied at a similar nitrogen loading rate. Foliar concentrations of nitrogen were high, typically between 3.5% and 4.5%, when swine lagoon effluent was applied at a nitrogen loading rate equivalent to 205 or 409 kg/ha. Zinc and copper concentrations were also relatively high when plants received these swine lagoon effluent treatments (45 to 55 ppm and 17 to 23 ppm, respectively). Sufficient variation among P. elongata clones was revealed for growth parameters and foliar nutrient concentrations to anticipate a benefit from the selection of genotypes that are the most efficient for remediation of animal waste, i.e., high biomass production and foliar nutrient accumulation. The data show that P. elongata has potential for use as a swine waste utilization species.