I'm playing the Magiculture 2.2.4 pack, with Rustic 1.0.3. And some crops, specifically Mallow Root recently, don't always even give back 1 root when harvested? I understand not having them drop as many as, say, chamomile, but it feels bad to harvest my crops and get -2 roots.

Should be fixed in the next update, which I'll be releasing soon. I'm guessing you'll need to manually update the mod in the pack you're playing.