But last year was also a wet year. The ground was constantly getting soaked. Thus the pigs' pen easily turned into a boggy mess with just a couple of days worth of rooting. I've discovered that I made a mistake allowing the pigs to stay in one spot until they destroyed all the Bermuda grass. I was so focused on ridding the ground of that grass that I failed to consider what was happening to the soil. The soil became waterlogged, boggy, and compacted. When it dried out for a few days after the pigs were removed, it looked like this"..........
Yes, all the Bermuda grass gone. Yes, rocks popped up that could easily be carried away. But cracking, compacted soil. Not good.
Reclaiming this soil has been work. Every shovelful comes up as a soil block. Each block has to be hand wacked into smaller chunks that the rototiller can handle. Even then it's a bucking-horse ride with the tiller. But by tilling in a layer of compost/mulch with the last tiller run I've ended up with a nice looking garden bed. It just was a lot of work getting to that end point.
A note: my soil lies atop pahoehoe lava. Think of it as soil atop an irregular, somewhat cracked concrete pad. So I don't have to take into consideration the formation of a hard pan layer. But I suspect that's what would have been created by the pigs in some other soil situation.
One other plus to using the pigs was that they fertilized the soil with their waste. I can already see the effects of that with lush, green regrowth of a few weeds. My first new crops are being planted into these pig areas, so I'm expecting to see good response to the pig fertilization.
What would I do different? I'd still use pigs but I'd be more careful to limit their time rooting when the soil gets wet with rain. Even during dry times, the pigs could easily cause compaction, so I'd move them more frequently. Before returning the pigpen to an area for repeat rooting (in order to rid the soil of Bermuda grass), I'd try breaking the soil with an oo bar or fork first so that the pigs didn't compact it as badly. They'd be able to reach those stolens faster, thus be moved off the spot quicker. And I would no more leave the pen in one spot for more than 24 hours. I'd try to move it at least twice daily.
Right now I have 6 little piglets in a moveable pen. They are not good rooters yet, but they scuffle the surface pretty well and eat up the surface grass & weeds. The weather is on the dry side right now, but I am still moving their pen at least once a day, often twice. I'll see how this method helps prevent compaction.
Using pigs to till is something new for me. So I'm still in the learning stage.