Biomass Production, C, N and P Sequestration In Short Rotation Plantation of Hybrid Poplar On Deep Row Applied Biosolids.

Biomass, carbon sequestration, and N and P storage of hybrid poplar were investigated to compare the effects of deep row incorporated (DRI) biosolids and commercial fertilizer on hybrid poplar response. Tree growth and foliage response was measured after two years of growth. Aboveground biomass production in the biosolids treatments was not different from the control treatment and ranged from 2.1±0.3 to 4.0±0.5 kg tree^-1. The fertilizer treatments produced significantly less biomass than the control and the biosolids treatments. Hybrid poplars sequestered up to 3.20±0.54 Mg C ha^-1, 71±12 kg N ha^-1, and 11.0±1.8 kg P ha^-1. The planting density capable of the N uptake in order to avoid N leaching was estimated at 3912 to 11363 trees ha^-1. Our results suggest increased hybrid poplar planting density and decreased application rates of DRI biosolids may decrease the risk of groundwater contamination with N.