Chicken Tractor

A chicken tractor is a pen with a roof and no floor, light enough to be dragged onto fresh ground every day or two. The birds inside eat what they can reach, scratch the surface open and manure where they stand, and then the pen moves on. What it is really for is placement: the same birds do the same work loose in a yard, but nobody chooses where.

Two shapes are common. A low pen about 3 by 3.7 m (10 by 12 ft) and 0.6 m (2 ft) high is easy to drag; an A-frame about 1.7 by 3 m and 1.7 m tall (5.5 by 10 by 5.5 ft) holds fewer birds for its footprint but can be worked standing up. Floor space runs from 0.14 to 0.28 square metres (1.5 to 3 sq ft) a bird, so the pen built sets the flock rather than the other way round. Moving is the whole management: every two or three days is enough at first, daily within a week or two, twice a day once the birds are heavy. A pen that stops moving stops working, because the manure that feeds a bed when it is spread thin burns the ground where it piles up.

The open bottom is what makes it useful and what makes it vulnerable. Anything that can dig under a rail or reach through mesh gets in, so the answer is a ring of electrified netting round the working area rather than a heavier pen. Birds are crushed under the frame during moves often enough that a second person with a broom is standard advice. A low pen under a solid roof with no draught is a hot box on a still afternoon, and in a serious heatwave the system is withdrawn rather than adjusted. Fresh poultry manure is strong enough to burn seedlings, and being raw it sets a wait before harvest: 90 days, or 120 where the part eaten touches the soil. Ageing a pile is not composting - only heating it right through to 60 C (140 F) deals with the pathogens. Upkeep is re-tensioning the cover and the joints, keeping the bottom rail true, and moving feed and water with the pen every time.