Nitrogen Fixing Bacteria as a foliar spray?

I've been doing a lot of mulberry research lately and I found an interesting concept for mulberry that could possibly translate over into apples or other tree crops: foliar application of nitrogen fixing bacteria. Since I can't remember much talk surrounding nitrogen fixing bacteria being an ingredient in foliar cocktails and, to be honest, I've never really heard much conversation on non-soil applications of n-fixing bacteria, I wanted to briefly post about it here.

According to this paper, foliar application of what they are calling "biofertilizers," (nitrogen fixing bacteria) is great because:

1.) N is being fixed close to the place of assimilation
2.) Some strains of N fixing bacteria on the leaf surface are antagonistic to many plant pathogens
3.) There is enough food material for nitrogen fixing bacteria on the leaf surface in the form of leaf leachates and degrading cuticles
4.) When sprayed on leaves, the bacteria don't experience as much competition by other microflora as they do in the soil.

In mulberries, foliar sprays of nitrogen fixing bacteria have been shown to control powdery mildew and rust (they also are controlled via soil applications). And in a crazy Ukranian paper that won't let me link to it right now (and it's also written in Russian), the N fixing bacteria "Azospirillum" increased the leaf content of vitamins B1 and B2 - by 8%, niacin by 11% and vitamin E by 16%. Broadly, it also improved leaf quality with a 20% increase in calcium, 55% increase in manganese, 23% in zinc, 50% increase in copper and 46% iron. It also increased photosynthetic pigments (they only mention carotene) by 46%

Those increases seem crazy to me, but given how easy it is to purchase strains of Azotobacter and Azospirillum online, it may be worth adding it to our foliar cocktails to see what happens.



Edited 2 time(s). Last edit at 12/15/2020 11:29PM by Eliza Greenman.

The microbe scene sort of feels like we need to collect them all, eh? Not unlike baseball cards when I was a kid!

Two of the three nitrogen fixing bacteria celebrated in this Sci Hub paper are included in Tainio's Micro5000. This concoction of foliar-friendly organisms also includes the "purple guys" I've spoken of with high praise elsewhere in the forum. Here's my conundrum: I have written a principal at Tainio twice now asking this question: What do you find in the field after application regarding colonization of Rhodopseudomonas palustris? This has to do with a debate about microbe survival put forth by the Quantum people concerning the acid bath of EM. Please review Quantum Thinking to come up to speed with me on this. Needless to say, after promising to get back to me, my friend never got back to me. Micro5000 is a dry formulation thus putting a third product approach on the table.

Spending hard-earned farm dollars means we want to purchase products that deliver. The profit margins of Advancing Eco Ag (who sells Micro5000 and all sorts of worthy nutrient formulations) weigh heavier every year. I think it would help, Eliza, to point out additional online sources of Azotobacter and Azospirillum. I for one would like to weave the nitrogen fixing angle into orchard trials just as I have the Quantum formulation. These biological notions are the cutting edge of holistic orcharding without a doubt. Other growers on this forum with biological gumption should have insights to share as well.

Thanks for sharing this 'Journal of Agricultural Science' paper but I do need to ask: Does that girl in the lower left corner of Sci-Hub really need to wave incessantly while we read it?

Lost Nation Orchard
Zone 4b in New Hampshire