Manure Management

One thing you quickly realize when raising animals is that the majority of work is related to moving materials around. You need to move large quantities of feed from the source to the animals' mouth, you need to to move water around the pasture for drinking, you need to collect and store hay and bedding, and you need a plan for handling the end product of all of that: manure. One of the biggest benefits of pasturing animals is that their manure is spread out over a large area, which nets a savings in labor from not having to move the manure around, and enriches the pasture at the same time. This benefit is only a benefit 6-8 months out of the year, though, as pasturing the animals in the winter in Western Washington is not an option. Instead, we need to keep the animals (and the pastures) protected, which means confining the animals to relatively small space.

In the picture above, you can see the outdoor area for the pigs. It's relatively small, just a couple thousand square feet at most. The pigs have access to this area all winter long, and it's separated from the main pasture by electric fence. I've learned that it's best to give the pigs as little space as possible, as they will quickly root up whatever space you give them, quickly turning the winter area into a mud and mucky mess. Instead of giving them a large quantity of space, I'm aiming at trying to give them the highest quality of space.

They have a relatively large indoor area, in which they do a lot of their manuring. They have a designated sleeping zone which they keep clean, and then they manure all around it. My strategy thus far has been to go for a deep bedding approach to managing this space. Every day, I put in a portion of a square bale of hay into the sleeping area, and spread out the hay from the previous day to cover the manured area. This keeps the space smelling good, but the pack of soiled hay slowly builds up over the winter (it also reduces a bit as it composts, but the build up occurs faster than the composting). After the pigs are back on pasture, I'll clean this out in the summer. This systems seems to work fairly well, and it seems scalable. I just increase the amount of clean hay I give them each day depending on the number of pigs. I use hay because it's the cheapest source of bedding I can find right now. I can usually get a square bale of low quality hay for $3. The pigs eat some of it, but most of it becomes their daily nest.

The outdoor area, on the other hand, is a bit more of a problem. My general goal is to keep the smell of my animals to a minimum. If there is a heavy smell of manure in the air, it means all sorts of bad things are happening: the health and welfare of the animals can be negatively affected, the environment is degraded because of the potential for large amounts of runnoff, my neighbors and my wife might not like me any more, a I don't want to work in a disgusting environment. Last year I didn't have any tools for handling the outdoor pasture area in the winter, and it got pretty gross, muddy, and uncomfortable for the pigs in a hurry. This year, I wanted to stockpile a source of cheap carbon to put down on the ground to help keep the muck under control, cover up some of the manure, and help to slow the runnoff of the manure slurry. The best source of carbon for this is wood chips, as they are easy to move around with the tractor bucket, easy to spread, and have a particle size that is neither too small or too large. Unfortunately, wood chips in this area seem to be going for $10-$12 a yard delivered. I figured I'd need 50-100 yards, and I don't want to fork over that much money this year. Instead, I got a much cheaper source of carbon from a farm down the road: rain soaked round bales:

I was able to get these bales for free, as they had been sitting outside for several years and the farmer was happy to get ride of them. Free is relative though, as it took a fair bit of labor for me to get them loaded into my truck and unloaded, as I could only carry 2 at a time. In the end, I think I got somewhere between 18-20 bales, and I've been unrolling 1 or 2 a week for the past two months to spread over the outdoor area. I was hoping the 18-20 would last me the whole year, but the pigs have been helping to spread them out as well, and I now have only 4-5 left. Although these bales are moldy, they are working as intended. The problem is that I would probably need to spread 4-5 out a week to keep the area as "clean" as I'd like it. It's making me worried that if I ever do switch over to wood chips, that my estimate of 100 yards of chips might be too low. The problem is that we have the unfortunate combination of very wet winters, a very high water table, and mostly above freezing temperatures. Every time it rains, there is no where for the water to go, so the much just keeps on forming. The manure becomes a bit of a slurry and the smell can start to build up.

I've been thinking a lot about how to best handle this in future years. It's clear that I don't need as much carbon if I can keep the area free of rain, as I can handle the indoor area fairly easily. I'm starting to think that perhaps I need to keep the winter pig range under cover and restrict them from going to spaces that get rained on. My fear is that I don't want to end up creating a system that is just a smaller, less efficient version of the commercial pig houses (I visited one when I was back in Michigan over Christmas--a story for another post). I'm also a bit concerned about the amount of manure and runnoff that I'll start generating as I grow the pig herd. I don't have a manure lagoon and I have no desire to build one, so want to continue to manage my manure in the way I'm doing now--as a damp but not liquid mix of carbon and manure that can be composted and spread back on the pastures or garlic beds. If anyone has any advice, please share!