So for now then, I should modify the base class - assuming I did that and I run the recompile and reobfuscate_srg bats, I end up with a file I can zip up as my mod, but I know that the base class file would need to be put into the minecraft jar and I the file names don't look like the ones inside the minecraft jar so I'm pretty sure just dropping them in won't work.
How would I go about recompiling the new base class files so that I can drop them into the jar (or have others do the same - shouldn't be conflicts with other mods as the behavior of the block is pretty much the same except when dealing with water source blocks)
Oh and also I could simply add a new block, but when a hoe is used to till the land, I'd have to change -that- class as well to produce the right block, or make custom tools for custom farmlands but that seems a bit excessive for what I'm trying to accomplish here.