Consuming fresh organic vegetables is the cornerstone of good health, and growing them yourself is a step towards sustainable living. Animal manure has been used as an organic fertilizer since the dawn of agriculture, some 10,000 years ago. However, recent E. coli outbreaks in Europe and the USA raise concerns over the potential food safety risks of using manure in the garden. While there are risks associated with using manure, by taking the necessary precautions, you can greatly reduce these risks and enjoy the fruits of your labor without concern.
Many E. coli outbreaks can be traced to fecal contamination from wild animals and domestic carnivores (including humans). Carnivore manure, including dog and cat manure, should not be used in the garden because it contains a particularly large amount of disease-causing bacteria and pathogens. Generally, manure from meat-eaters is more likely to carry disease than manure from herbivores.
Bad Gato
Cat scat can be especially dangerous to pregnant women or those with a compromised immune system. Cat scat is a vector for toxoplasmosis, a parasitic disease that can remain active in the soil for more than a year. This is troubling for those of us with raised vegetable beds that our cats find irresistible for use as litter boxes.
Solarizing the soil through winter and spring will kill toxoplasmosis and make the bed safe for planting. After watering the soil, place a large piece of clear plastic over the garden to heat the soil and kill the disease. You’ll get the added benefit of killing many weed seeds.
Keeping the kitties out of the vegetable garden takes mental dexterity and trial and error. Even though cats can climb, many of them can be deterred with fencing. I use willow fences for a rustic look, but chicken wire works well too. Some felines can’t stand walking on plastic mulch, and others don’t like walking on rocks. Planting a row of offensively aromatic plants may also keep some prima donna cats from prowling around.
From the farm
Horse and cow manure is generally safe for the garden as long as it has been composted or aged. Cow manure is easier to find at most local nurseries than horse manure. Fresh horse and cow manure contains bacteria, and a lot of urine. Urine is very salty and can damage plants. Commercially produced steer manure can also be high in urine because at most commercial feeding operations, e.g. CAFOs or confined animal feeding operations, where the manure is collected, cows are being readied for slaughter and they are confined in pens with limited mobility. Before applying manure, test your soil for salt content. Don’t apply manure to soils that are high in salt.
Commercially composted manure has been heated to over 150 degrees to kill weeds, pathogens, and bacteria. Aged manure has been allowed to sit and dry out, typically for six months or more, but will still contain weed seeds and could still contain bacteria. Aged or composted manure helps improve soil texture and water-holding capacity.
Best practices
If you are going to apply fresh manure, to reduce the food safety risks, the USDA National Organic Program recommends applying it at least 120 days before harvesting vegetables. This means the best time to apply fresh manure is in the fall. This will give ample time for any bacteria to die, as most bacteria thrive in a warm, moist environment, not in our dry, cold winter climate. Remember, fresh manure is an excellent source of weed seeds and will increase your vegetable garden weed woes.
Good horticultural practices will also reduce the risk of foodborne illnesses. The location of your vegetable garden can make a difference. Don’t grow your vegetables in an area where surface water will run onto it from either a manure storage area or land fertilized with fresh manure. In addition, don’t grow vegetables in the leach field of a septic system.
Mulching your vegetable beds will prevent water drops from bouncing off applied manure onto your crops. Mulch may deter cats from pussy footing around your vegetables, and will provide a layer of protection between vine crops such as squash and melons and manure-amended soil. Mulch provides additional benefits of water conservation and weed suppression.
Thoroughly washing all food grown in manure-fertilized gardens will also reduce the risk of contamination. Wash them just before eating to avoid spoilage. Scrub root crops such as carrots, beets, and potatoes, and thick-skinned vine crops, such as melons and squash, with a scrub brush and cool water. Better yet, peel them before eating. Even though you don’t eat the skins of squash and melons, when you slice them, bacteria present on the skin can be transferred to the flesh. Remove and discard the outer leaves of leafy vegetables before washing them.
Growing your own organic food supply can be very satisfying and will supply your family with top-notch produce to enjoy. Aged manure from vegetarian animals – horses, cows, goats, sheep, and chickens – is an excellent amendment for our soils, and with the proper handling, poses little risk. This Colorado State University Extension publication is a good additional resource for using manure in the garden.
We collect shit from our cattle, mix it with a bit of water and store it in 10 litre covered buckets for a year. We also buy in sheep shit in convenient seed bags, maybe 30 kgs. It has been well aged, a few to several years, dug our under the removeable slatted floors in holdng pens in wool sheds by young lads keen to make a few bob and not afraid of a little hard yakker. tt comes in the form of loose 1 cm balls for about $5/bag.
We spread the sheep shit on the surface and rake it lightly when we sow a green manure crop. The cattle shit is poured around the base of tomato and pepper plants in the growing season.
We dig in bokashi before sowing or planting.
I’m afraid we aren’t very strict paleo in our garden. Lots of tomatoes, beans and potatoes. They go well on the plate with our beef, anyway.
would it work to keep a compost toilet for vegan guests?
So they could take their deposits home with them?
My cattle are mostly vegan but get their B12 from insects, slugs and worms that sort of geeaten with the pasture. Vegans should be OK with that. But what do I know… just a dumb farmer.
Another thing to be very careful about when getting composted manure is to be sure the animal hasn’t grazed on grass that has been sprayed with herbicides. Certain herbicides can survive even a cow’s gut (even more likely it’ll make it through a horse’s gut) and the composting process. You’ll spread it on your garden thinking you’re doing good, just to watch all your plants die. ‘Twould be sad, indeed.
That happened locally with compost from the recycling centre. A lot of gardens (solanaecea, mostly) took a hit, The herbicide in question is a commonly used broadleaf chemical used in cropping and hugely common in lawns! Lawn clippings are the big culprit in killer compost.
I can’t imagine anyone grazing after spraying with that one… might kill your animals. Fortunately, the most common chemical, glyphosate, breaks down very quickly and comes without a poison label (even though it probably causes birth defects)
I find using Cat traps and effective measure in keeping them off my garden. Off to the pound they go. Had a neighbour complain to me about it once. I told them as the law states that when the Cat enters my property i am able to deal with the situation accordingly. My advice was if you do not like it then keep the cat indoors.
Traps and the pound. That’s kind. We let the kelpie express her natural inclination with feral cats.
Leslie,
We had a cat problem in our garden as well and I found that if I sprinkle coffee grounds around it keeps the cats off. I guess they don’t like coffee.
He is really a bad gato. 😀
I always get a kick out of “Vegans”. Don’t eat meat but will use all by products such as “ANIMAL” manure. To them, its “vegan and organic” even though it is DIRECTLY from a cow. It is still a product from an animal any way you look at it. What hypocrite’s, if THEY deem it is a non animal product, its ok. But not for those that want to eat meat, its not. If you want to be a vegan, you cannot use ANY animal by-product, or product made by use of an animal by product. Forget your veggies that have been grown using ANIMAL manures!!The term “ethical vegan” is often applied to those who not only follow a vegan diet but extend the vegan philosophy into other areas of their lives and oppose the use of animals and animal products for any purpose.[4