Manure Happens

Last week I had a customer ask if I would sell her some manure. The last time I was asked to sell poop it was back in the late 90’s to a rose gardeners’ club when I raised meat rabbits. Delivering the bags of bunny beans that had rolled down under the cages into gutters which were emptied into buckets, I felt guilty taking money for manure so one of the club members gave me a gift certificate to her restaurant. I joke each spring I give my mom a load of crap that makes her happy, unlike when I was a teenager.But as I’ve learned over the years, it’s not manure that should be put on the garden, it’s compost. There’s a difference.Everyone thinks that manure is animal waste…not true. Green manure, commonly referred to as cover crops, are plants grown to protect the soil during non-production and then plowed under to increase organic matter prior to planting. Sometimes cover crops also serve the additional purpose of fixing nitrogen in the soil.Is the nitrogen broken? No.“Fixing” nitrogen refers to the process that turns the nitrogen gas in the air into compounds that plants are able to use. Plants that have the capability to fix nitrogen have nodules on their roots that convert atmospheric nitrogen into water-soluble nitrates. Nitrogen is the most used element by plants on the planet. Without it, nothing would grow.As a livestock farmer however, my manure is brown. It’s also hot, not only in terms of temperature, but in the amount of soluble nitrates, mainly ammonia. To combat high nitrogen levels in manure and urine from animal waste carbon is needed. Herbivores, such as cows, horses, goats, sheep and rabbits have a lower amount of nitrogen in their manure as opposed to omnivores such as pigs, turkeys and chickens.Living in rural Pennsylvania where industrial hog and poultry barns dot the landscape, I’ve learned to tell the difference between species when the wind blows. It’s not hard. When the dairy farm spreads their liquid manure, I might light a scented candle or burn a stick of incense, but when hog sludge or poultry litter gets spread, I need to close the windows…fast. Blame it all on the nitrogen breaking down into ammonia.As a pasture-based farmer, the animals spread their manure themselves except in the winter when they are kept out of the pastures due to the damage they can wreak on dormant grasses with their hooves and over-grazing. Manure collects around the hay feeders and in the barn where the mommas and babies are sheltered.In order to control the ammonia build-up, carbon must be regularly added. Carbon can be straw or sawdust. While sawdust is more effective at reducing ammonia, straw keeps the animals warmer during inclement winter weather and funnels away moisture.Why don’t I clean it up before the nitrogen breaks down into ammonia? A few reasons.The decomposition of manure is temperature dependent. During bitter cold weather the breakdown is extremely slow. However, it is still decomposing which is an exothermic reaction, meaning it gives off heat. A good bedding and manure pack will help keep animals warm and build up what amounts to insulation between them and the bare ground or concrete.The biggest reason, though, is logistics--where to put the animals when I clean out the areas in which they are housed. Mucking out a single pen housing a ewe with a few lambs is easy, requiring only a pitchfork, a bucket and a few minutes, but hundreds of animals means heavy equipment and several hours.“I bet you’re happy the temperature is warming up,” is a common greeting from my customers. Yes, lovely. For the next few weeks my life will revolve around moving tons of manure from the winter pens and paddocks to long windrows behind the hay barn where it will continue the process of breaking down into rich, dark, moist compost that can safely be spread on the fields and crops without overloading the plants with nitrogen which will either stunt their growth or kill them.In addition to manure and soiled bedding, my compost piles include mortality. Mortality composting is the safest way to properly dispose of dead livestock and butchering waste. Small ruminants can be reduced to little more than bones in a few weeks, calves and pigs in a few months and larger animals in a year.All compost needs to be turned to incorporate air to allow for the microbes, bugs, beetles, fungi and worms to do their jobs. Occasionally when I’m doing this my neighbors will hear me squeal like a little girl as the skid loader bucket turns over a nest of freshly hatched snakes who like to lay their eggs in the warm piles.How hot do the piles get? Plenty hot.A good pile of compost can reach 170 degrees Fahrenheit, but the average temperature hovers around one hundred degrees. These temperatures not only reduce the nitrogen in the manure, but also break down the cellulose into soil, and bake weed seeds to prevent gemination.Innovative farmers collaborating with chefs have been experimenting with building giant sous vides by vacuum-sealing whole vegetables in bags, packing them in a sealable drum with water and them burying it in a compost heap a few days ahead of the big party. I guess you could consider that a vegetarian’s version of a pit-roasted pig.Spring means spreading the old piles, making new piles and yes, even giving a few bags away to a customer. I hope she owns a restaurant.