Cover crops require a fair amount of extra seed. And yes some seed is cheap, but what might a person grow that can produce lots of extra seed to use in cover cropping. I know this context/climate dependent. I like using winter rye and I do grow some to harvest seed and straw. It's a strong plant and produces well on poor soil. I'm trying test other cover crops that work well in my content and that I can grow to seed and have lots to use... to eat, replant and use as cover crop.