Manure is a beneficial animal waste product to use in the produce garden, but it can also be a threat to food safety, either killing the plants or passing on some serious gastrointestinal infections to humans. It’s not exactly about nutrition, but it is about food safety.
The biggest thing to remember is to never put raw manure directly on your garden plot where it can come in contact with harvested produce or any plants in the garden. The proper protocols to take in storing manure and applying it should be carefully followed to ensure there is no risk of contamination. This is especially true if you’re selling your produce because the consequences of bacterial contamination can be costly.
Manure should be stored at least 100 yards from the produce growing area, and keep in mind, this applies to small backyard gardens, too. Care must be taken to avoid any run-off from the manure pile into the produce area. For those with truck farms, a periodic check of the manure pile is necessary, along with a written record of the date it was checked.
Mark Hutchinson is a horticulturist with the University of Maine Cooperative Extension and a faculty member at the Maine Compost School. He has some very good advice for backyard gardeners: “You’re no longer going to apply fresh manure and two days later do your planting. Rather, you should apply it in the fall, let a cover crop grow and allow the manures to mature,” Hutchinson said. “It’s a food-safety issue rather than a nutrient issue. We’ve all seen the outbreaks of E. coli over the past couple of years.”
Interestingly, not all manures have the same levels of nutrients. Chicken manure is very high in ammonia, phosphorous and nitrogen. Even after its composted, it can still burn the tender roots of young plants. Goat and sheep manure in drier and easier to apply, and it doesn’t smell as strong as other manures. Don’t use dog, cat, and pig manure because they are a disease threat and may carry harmful bacteria and parasites.
Here are some easy instructions to follow in spreading manure:
1. Spread raw manure in the fall, and never apply to a garden that has been planted. Apply at least 60 days before harvest if the vegetables or fruit is not going to be cooked before being eaten.
2. Apply manure just before a rain. The rain will help to wash in the nutrients.
3. Get your soil tested before applying manure. You might not need to add any additional nutrients to the soil.
4. Do not over-apply. Some people think that if one handful is good, then three handfuls must be better. It’s not true.
5. Wash. Wash your hands and wash all raw vegetables and fruits before eating.