Ex situ growth and biomass of Populus bioenergy crops irrigated and fertilized with landfill leachate

Merging traditional intensive forestry with waste management offers dual goals of fiber and bioenergy production, along with environmental benefits such as soil/water remediation and carbon sequestration. As part of an ongoing effort to acquire data about initial genotypic performance, we evaluated: (1) the early aboveground growth of trees belonging to currently utilized Populus genotypes subjected to irrigation with municipal solid waste landfill leachate or non-fertilized well water (control), and (2) the above- and below-ground biomass of the trees after 70 days of growth. We determined height, diameter, and number of leaves at 28, 42, 56, and 70 days after planting (DAP), along with stem, leaf, and root dry mass by testing six Populus clones (DN34, DN5, I4551, NC14104, NM2, NM6) grown in a greenhouse in a split–split plot, repeated measures design with two blocks, two treatments (whole-plots), six clones (sub-plots), and four sampling dates (sub–sub-plots, repeated measure). Treatments (leachate, water) were applied every other day beginning 42 DAP. The leachate-treated trees exhibited greater height, diameter, and number of leaves at 56 and 70 DAP (P<0.05). There was broad variation in clonal responses to leachate treatment for dry mass, with a general trend of leachate-treated trees exhibiting greater stem and leaf dry mass (P<0.05), but negligible differences for root dry mass (P> 0.05). Overall, genotypic responses to the leachate treatment were clone-specific for all traits.