I quit after 5 acres with a mix of soybeans and cowpeas. Soybeans if they get nipped off below the first 2 leaves they are done. I was left with 5 acres of weeds and grass.
This was on 400 acres of property and medium deer density. I'll just add that I had reasonable success the first year I planted them, but in the scond year, the deer hit them as soon as they emerged.
Yep, Its called the gallager fence system. Been using it for 3 years on sunflowers in a high deer density area. Works very well if done correctly. Don't use shortcuts. Use as much white as you can, tape, turbo wire, step in posts etc. Also use a good charger with at least 3 ground rods. It will work. I'm doing eagle beans this spring and will be using the fence system.
He had to get a permit, year round.
Took about 3 years to kill enough to
do any good. He shot. His cousin that
bought 7 joining acres from my Granny
shot.
I was just a kid that went "to the country"
as we all called it a lot to fish, ride dirt bikes,
go carts and do whatever.
I shot so many from my Granny's
front porch, I got tired of dragging
them to the "flat rocks" AKA bone pile
with a chain and tractor.
In other words, deer eat the heck
out of soybeans.
A lot of it depends on what is around your soybeans. in Illinois I plant 5 acres and it does pretty good. It is in an extremely high deer population but has other AG fields nearby. Another key ingredient in success is timely rain. 30 acres should be more than enough. Good luck.