Cumulative nitrogen uptake by loblolly pine and sweetgum receiving irrigation and fertilization through a ten-year rotation

This dataset provides plot-level data of cumulative nitrogen (N) uptake for loblolly pine (<em>Pinus taeda</em> L.) and American sweetgum (<em>Liquidambar styraciflua</em> L.) receiving irrigation and fertilization through a ten-year rotation in the southeastern USA. The study was located within the US Department of Energy, Savannah River Site on the Upper Coastal Plain physiographic region, near Aiken, SC (33o15’ N; 81o36’ W). Trees were planted at 2.5 × 3.0 m spacing (1333 trees ha-1) distributed across three replications (experimental blocks). Fertilization was applied via drip irrigation and was split among 26 weekly applications beginning in April of each year and extending through October. Fertilization rates increased through stand development to correspond with demand and reduce N leaching. Sweetgum and loblolly pine received 40 kg N ha-1 yr-1 in the first two years, 80 kg N ha-1 yr-1 in years three and four, and then 120 kg N ha-1 yr-1 through the end of rotation. Allometric equations generated from destructive harvests and tissue N laboratory determinations were applied to annual diameter measurements to scale up N content to the plot-level. Annual N uptake was calculated as the change in total N content of dormant season biomass from one year to the next plus the N content of leaf litter and fine root turnover. More details about the experiment from which data come from can be found in Aubrey et al. (2012), Coyle et al. (2016), and Ferreira et al. (2023). <br> Metadata Variable coding and units: sg = sweetgum lp = loblolly pine cumulative N uptake = kg N ha-1 <br>