We are studying the uptake and internal recycling of nitrogen in perennial crops using 15N labeled N sources.

Kristie Dennison, who set up the experiment, next to the 15N labeled plants.

Kristie Dennison, who set up the experiment, next to the 15N labeled plants.

As part of the NEWBio project, an experiment was set up at Rock Springs (near State College, PA) with the shrub willow cultivar 'Preble'. Nitrogen with 5% 15N enrichment was added to root enclosures to label individual shrub willow plants. This allows tracking nitrogen uptake, storage, and its re-use in successive growing seasons. The plants in the picture have less than one year of aboveground growth.