You do NOT need to buy additional tool carriers or drawbars to switch between (subsoiler, root digger, bed shaper, cultivators and ridgers. You only need 1, so if you happen to own one of those other attachments (just mentioned) you already have the drawbar and tool carrier you need for spike tooth harrow.)
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Made by Aldo Biagioli of Italy, this spike-tooth harrow is 28” wide, and tines can be removed individually if narrower tillage width is required (the frame remains the full width, however). The teeth are staggered from each other so that the 12 teeth all contact the soil in different spots to give full-width coverage. This is a great low-tech tool for roughing up the soil for light weeding, incorporating cover crops, crust-busting, etc. Tines are angled back slightly top-to-bottom so that organic material will not catch on the tines as badly. Tines are about 5 inches long.
Dailey's Farm & Walk-Behind Tractors