Externally applied nitrogen has the benefit that the wheat plant doesn't need to divert sugars to the symbiotes for nitrogen production, and can instead spend it on making heads of grain.
As cool as it is, I'm not clear that it actually helps efficiency in industrial agriculture. Partly depends on how efficient the symbiotes are vs. how expensive synthetic fertilizer production is.
Interesting. I am not an expert, and it sounds like you are, so thanks for adding that.
Even if it wasn't quite as efficient, could it be worth the trade-off in terms of reduced CO2? As the application of synthetic fertiliser etc is very fossil fuel intensive?
I'm not an expert either, I just know some and have heard of some of these issues—so I don't have anything definitive to say, just that it's not a clear win in my eyes.
I also don't know if the wheat plants are even sugar-limited, for that matter! I guess what I'm saying is "plants are complicated". :-P
As cool as it is, I'm not clear that it actually helps efficiency in industrial agriculture. Partly depends on how efficient the symbiotes are vs. how expensive synthetic fertilizer production is.