I was exploring a test world, and as I was approaching a village (first village I've seen in my pack since I added AgriCraft) I got the following crash:
http://pastebin.com/NB65pPtV
This is with AgriCraft 2.0.0a on 1.8.9
Edit: Tested with 2.0.0a1 as well, still get the same crash.

Well it looks like something in one of the crops threw off the rendering code... This may take a bit to fix...

The best I can say now is to turn off AgriCraft worldgen and recreate the world for now... (If that's o.k.)

Also you might want to turn off seed storage.

See also the log from #618, http://pastebin.com/7YABZaF5.

I think this is due to the fact that when I created that class I assumed that blocks would be rendered with DefaultVertexFormats.BLOCK, my first guess is that it's rendering with a different VertexFormat and hence too much data is passed to the vertexbuffer when tessellating a vertex.
1.9 Should ahve fixed this though as this has been fully rewritten.

That's what I figured about 1.9...

For the sake of clarification, will this fix be back-ported to 1.8.9? --or, now that I see it, is this in 2.0.0a3?

Yup.

Given the lack of response to the latest post in this thread, I have gone ahead and tested this issue in 2.0.0a3 and verified that it remains symptomatic.

I am not doing any work on 1.8 or 1.7 anymore, so it'll be up to @RlonRyan if the wants to backport it or not.

Is there a work-around for this? I've had to resort to deleting all Agricraft blocks from region files that fail to render correctly because players can't load their bases.