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The ins and outs of manures

Birdy, birdy in the sky, dropped some whitewash in my eye; I’m sure glad that cows don’t fly!

Birdy, birdy in the sky, dropped some whitewash in my eye;

I’m sure glad that cows don’t fly!

Perhaps now is a good time to assess and address the indelicate topic of turds, because some gardeners may be sheepish about using it or concerned about getting a load of crap.  So here are a few fecal facts and follies so you don’t get a bum deal before it’s a dung deal.  (Oh boy, that stunk….)

For centuries now, there’s been a lot of fuss over feces because these treasures from the tush have added precious organic matter and important nutrients to soils, and many a millionaire has been made selling the muck too.  Apparently, the ‘s’ word comes from the 1600s when manures for market were stored in bundles and transported by ship below deck, which occasionally got wet, then fermented, creating a dangerous build-up of methane gas.  The first poor sailor with a lantern would blow up the ship and crew, so eventually instructions were stamped on the fabric to “Stow High In Transit,” so hence the term was born.

There’s a multitude of number 2’s that you can use, but not all excrement is created equal because whatever the critter eats, is what it excretes – be it herbi-, omni- or carnivore, and those end products can really range in nutrient value and contents.

However, it’s from whence it came that’s the most important, because the droppings may come from some dubious derrieres such as the factory farm chickens or pharma-fed bovines in a feedlot. That stuff could almost be considered hazardous waste due to the cocktail of residues that tag along with it, such as pesticides, pathogens, parasites, fertilizers, herbicides, hormones, de-wormers (that keep on working), arsenic and antibiotics.  So buyers beware and do your ‘doo’ diligence!

Using the local “safe” stuff can have plenty of perils too. For instance, some seeds stay intact through the digestive tract, which will happily sow themselves in your garden beds, the manure may already be weedy if left uncovered. If it’s poultry piles, it’ll need to mellow for months because it’s too hot to handle for the plants.  Some raisers of grazers say take it away, but it can sure poop you out trying to shovel it, unless you can pay for the trucking.  It may also come mixed with shavings, so check that it’s not cedar.

Buying it by the bag can sure rack up the bill at the till if you need any sizable amounts, and those sterilized stools will have lost much of the microbes and nutrients in the process, leaving you with basically denatured organic matter, along with possibly some icky things in it.  The steer manure at the local fundraiser or from your neighbour’s nag Nellie will be more “alive”, though it may come with some weed seeds.

Mushroom “manure” is compost waste from commercial farms, which is a mix of wheat straw, dried blood, horse poop and chalk.  Another source says it has wheat straw, peat moss, cottonseed meal, gypsum, lime and chicken litter, so maybe it depends on where it comes from. Either way, it’s all mixed, composted and then sterilized for the growing process, which only lasts a few weeks. The sellers say it’s a good source of nutrients and trace elements, as well as a useful soil conditioner, ‘butt’ much of the nitrogen is used up, the microbes will have been wiped out from the heat and the chalk is very alkaline and should not be used on acid-loving plants.  If that doesn’t get you down in the dumps, then this might - it may also contain nasty pesticide residues like organochlorides, which are used against the fungus gnat and chemicals to treat the straw, as well as to sterilize the compost.

So if you do want to muck with manures, I’d layer it into your compost along with as much variety of other organic matter as you can such as leaves, woodchips and kitchen waste, and let the critters do their thing with it first.  But really, grazers are just giving you a lot of processed, nutrient-deficient, recycled greens, so I’d stick with good, fresh-cut grass – I use it in my compost.  Nature’s truly perfect poop comes from the worm, whose rich castings produce the ideal blend of NPK and minerals for your plants.   So make sure your soil food web is consistently fed so they can keep pumping out that marvelous manure from the mulches into fantastic and free fertilizer.