Vitousek et al. 1998. Insights from a simple nitrogen budget model

An implementation of a simple nitrogen budget model:
http://rpubs.com/hankstevens/vitousek1

from Vitousek, P. M., Hedin, L. O., Matson, P. A., Fownes, J. H., & Neff, J. (1998). Within-system element cycles, input-output budgets, and nutrient limitation. In M. L. Pace & P. M. Groffman (Eds.), Success, Limitations, And Frontiers Of Ecosystem Science (pp. 432–451). Springer, New York.