Saturday 6 October 2012

Intensive sustainable crofting : "The Chicken Tractor"

The "Chicken Tractor" is, I think, an American idea. Its a lightweight portable poultry house without a floor.The hens inside scratch and rake the grass underneath until the vegetation is removed the soil fertilised and then the whole thing moves on a length and does the next bed. You can clear, cultivate and fertilise without any machinery and raise poultry too.

Poultry fold unit

This idea reminded me of the poultry fold units that were quite common when I was a boy. These were used on grass fields or to glean stubble after harvest. They were light, strong, vermin proof and very well made.

Units were moved daily, food and water had to be carried to them and eggs collected but labour was cheap just like here where the opportunity cost of my time is zero as a retired person.

As the poultry moved over the field they ate grass, then harrowed and fertilised the grassland with substantial amounts of poultry manure. My design is 15' x 4' roughly 9 sq yds. In theory two of these units will cover an acre in 263 days about 30 weeks.

 This is very  crude drawing but good enough for the Playboy Joiner to work from. The lighter end with the nest box has a pair of small wheels and the heavy end is capable of being lifted on to two larger wheels for transport. The design of this aspect needs more thought! and advice.

Now for the arithmetic. Hen manure is hot stuff; 4% Nitrogen, 6% Phosphorous and 4% Potassium. balanced for grass production. Fifteen hens produce about 1.8kg of fresh manure a day or 0.5kg of 4:6:4 fertiliser dry matter. OK enough of that.....its a lot of fertiliser and combined with nitrogen fixing clover should avoid the need for chemical fertlisers......we'll see. 


Jon said...

Another fascinating article, Tom, and a great idea. Look forward to seeing the first prototype. But when are you going to stop mixing your metric and imperial measurements? The new Hubble mirror was the wrong size because NASA did the same thing. Equally catastrophic mistakes might happen with your chicken runs.

Tom Bryson said...

I adopted the metric system in 1974. My measurements are mixed because 25% of the readership is in the USA where they are still in the medieval era using "Imperial". Maps in the US still use "rods" five and a half yards to measure canoe portages between lakes, farms are basically " quarter sections" or 160 acres or a quarter of a square mile. Its time they threw off the yoke of Imperialism and joined the 21st Century don't you think. I will stick to Metric from now on.

wildwritingfromtheedge.blogspot said...

Very interesting.
I believe that the concept of using hens to weed & manure ground is ancient & not necessarily an American idea. The use of arks is possibly something that happened where ever hens were kept.

Kellie Castle, when Kathy Sawyer was gardener there, she trialed an ark system using as near as possible Fife hens.

I breed & keep Scot's Greys - the original crofters hens & use them for various things about the croft. Everything does & should intereact.