[DesertVarnish]

Is it actually standard practice to use nitrogen fertilizers with soybeans? Soy is a nitrogen fixer and I've read that nitrogen fertilizers often reduce yields for soybeans because it interferes with nodulation and undermines that plant's nitrogen fixing capacities.

[photochemsyn]

Apparently soybeans are often grown in a double-cropping rotation, in which maize is planted first (along with N and P fertilization), and then no additional fertilizer is applied to the following soybean crop.

This seems to be a comprehensive discussion (for South Dakota farmers anyway, pdf):

https://extension.sdstate.edu/sites/default/files/2020-03/S-...

[cmroanirgo]

Making use of nitrogen fixing plants alleviates the need of fertilization. An easy one: clover. Bees also love clover. However you can explore other systems of cover cropping (I recall Diakon radishes draw up nitrogen from down low, up to the surface) which you terminate before seeding your main crop.

[washbrain]

Oh, great question actually. I mostly know wheat farmers, so that's the model that I have in my head, but yeah it would make sense they fix nitrogen.