The Lely harrow (Fig. 2) is a lightweight tool with
very flexible tines that vibrate to rip weeds from the
soil. The implement's light weight can be a "cure or
curse" -the harrow is easily maneuvered with a
low-horsepower tractor, but its cultivation efficiency
is reduced on hard-packed or crusted soils. Tine
intensity is modified on a tine-by-tine basis.