John KempfRegenerative Agriculture Entrepreneur

Podcast: Overcoming the Ammonium Death Spiral

8 Jul 2026 · 1 min

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1:10

In this monologue, the speaker explains how excessive nitrogen fertilization forces plants to divert their limited sugar reserves toward stress mitigation and ammonium assimilation. Over‑application of nitrogen lowers plant sap pH and raises ammonium levels, signaling severe stress. Because the plant must also engage in photorespiration to cope with high ammonium, a by‑product of photorespiration is additional ammonium, creating a self‑reinforcing feedback loop the speaker calls the “ammonium death spiral.” The discussion highlights why this cycle depletes sugars, impairs carbon skeleton formation, and ultimately reduces crop productivity, underscoring the need for more balanced nitrogen management on farms.

Chapters

you know, the plant has to prioritize staying alive first. And so it's going to use its sugars to reduce stress, move things around in the plant, and, you know, do all kinds of stuff to reduce stress. But then the next thing it's going to do is process nitrogen and make carbon skeletons for ammonium assimilation. And that's where farmers really shoot themselves in the foot, is because they put out so much nitrogen that they suck down their sugars and then you get the low pH and the low pH is just an indicator of something else that's going on in the plant. The low pH and high ammonium is the plant has a lot of stress, so it's using sugars for that and then it's using sugars for all this, this big slug of nitrogen that's out there, especially the ammonium. And then there's not a lot left for everything else. There's not even enough for the ammonium processing. And so the plant is constantly in this state of low sugar And then it's made worse because the plant has to photorespire to deal with the effects of having all this ammonium in the sap. And I call it the ammonium death spiral because you have too much ammonium already, and then a byproduct of photorespiration is more ammonium.