You’re ready to get chickens, you’re totally pumped. And then you do some soil tests (just to be safe) and discover you have high levels of lead in your soil.
So what do you do – turn around, relinquish your hopes of having a feathered flock of your own and suppress the urge to cry? Wrong, you get informed, do a good design and work out a strategy, because there is always a way.
But first, what is lead and why all the fuss? Lead is a heavy metal which, if ingested, is poisonous to animals and humans (especially babies and small children). It damages the nervous system, can cause brain disorders and compromise brain development. The other major downer is that it does not ‘break down’ and leave your system, instead it accumulates in both soft tissues and bones. So chickens, who love to scratch, peck and eat soil, can ingest lead and pass a large portion of it straight into their eggs.
Where does lead come from?? It usually finds its way into our soils in the form of old flaky house paint. Up until the 1970s house paint consisted of 50% lead – ouch. These days house paint has around 0.1% – you can read all the facts and figures about it here.
The other common way it’ll find its way into the soil is through petrol runoff, think busy roads and inheriting homes and gardens which used to belong to mechanics or wanna-be mechanics. Car graveyards, old sheds and oily puddles are good indicators of lead being in the soil. But of course, always get it tested if you’re suspicious.
So, now to the designing bit. One option is to scrape your site of all the contaminated soil and replace the whole lot with new stuff, yes – this quickly adds up and empties your piggy bank. But it is an option.
Another approach is to work with what you have. You can literally cover your contaminated soils with geo-fabric to seal it soil off. Then, add a layer of shade cloth on top as extra reinforcement and to prevent chickens from trying to scratch through the geo-fabric. Finally, add a deep litter layer of either straw, woodchips or another type of mulch substance for the chickens to scratch, play and live in.
This low-tech system is highly effective in providing a safe, healthy and happy space for your chickens to live in. The top layer of straw/mulch provides the deep litter the chickens need to have their dust baths, soak up their poo and ultimately transform into compost. You’ll need to replace this mulch once or twice a year to keep things fresh. And of course, the stuff you scrape out of there is more valuable than gold – seriously, it has major life giving properties for your food production spaces.
Our friend Margaret has some heavy lead contamination in her soils in urban Hobart. After a good year of research, thinking and learning she now has 3 small bantams, Snowflake, Nugget and Purple (she let her grandchildren name them). Margaret is smart – really smart, and has started small, both with the size of her chickens and the house she has built for them as she wants to make sure she’s got a good system before expanding their set-up.
Despite having lead contaminated soils, Margaret has been able to apply good design to integrate chickens into her garden
After excavating the contaminated soil out of one area she lined it with weed mat and placed a deep litter layer on top. It’s totally fine that she hasn’t used geo-fabric and shade cloth as we suggest in our above diagram, the weed mat will do the same job – we just outlined a bomb proof option to be super safe.
Now Margaret’s happy with the system, she’s planning on extending the run to provide more space for her bantams to stretch their legs. FYI, each chicken likes to have a minimum of 2 square feet of floor space inside their house. Outside, give them a minimum of 10 square feet per bird. You can read lots more about chickens and their needs at Backyard Chickens.
Snowflake keeping a safe distance from me while I check out her lil’ home.
A close up of the chicken house. The black weed mat is providing a protective layer between the contaminated soil and the chicken’s mulch layer.
While Margaret’s system is quite small, this design solution can be up-scaled significantly. Depending on your capacity and budget, it could easily be applied to 1/4 acre block if required.
MORE INFORMATION & RESOURCES
- If you’d like more information about lead, visit The Lead Group, in particular check out their page on lead and gardening.
- Talk to your local Environment Protection Agency (EPA) to find out local regulations of safe levels of lead in your soils, if you’re in Tasmania you can contact them here.
- FYI the Tasmania EPA tell me that the acceptable levels of lead in ‘clean fill’ is 300ppm.
- Want to know more about all things chicken? See what our mates have to say at Very Edible Gardens.
- If you live in Tasmania and want to get your soil or water tested for lead and other heavy metals contact either of these two these labs:
Photo credit to Kirsten Bradley from Milkwood Permaculture for our cover photo, thanks for photographing our chickens :-).
*Your blogger is Hannah Moloney: Co-director of Good Life Permaculture and lover of all things fun and garden-esk