For example, once a tree has essentially as much CO2 as it can use, other conditions such as soil nitrogen availability, will become limiting. (realclimate.org)
By Cheryl Mackowiak, IFAS Extension, University of Florida Given the challenges of excessive water, are there ways we can determine, after significant rain events, if soil nitrogen has leached beyond our crop's root zone? (wikinvest.com)
Litterfall 15N abundance indicates declining soil nitrogen availability in a free - air CO2 enrichment experiment. (montanaclimate.org)