Theory 63/Nitrogen cycle/Termination phase
The Cycle Closes on Anoxia
The claim
Denitrification completes the cycle only above a threshold in the ratio of anoxia to nitrate supply, so well-aerated soils retain nitrogen.
01Mechanism
Denitrifiers require low oxygen; the ratio determines the extent.
02Prediction
Denitrification should track the ratio.
03Refutation
Denitrification tracking nitrate alone would remove oxygen.