EFFECT OF AMPLITUDE AND FREQUENCY ON SOIL BREAK-UP BY AN OSCILLATING TILLAGE TOOL IN A SOIL BIN EXPERIMENT

Experiments were conducted in a soil bin to study the effect of amplitude and frequency of an oscillating tillage tool on fragmentation of Kharagpur sandy clay loam soil. It was observed that the maximum utilization of energy occurs at an oscillation frequency close to the natural frequency of the soil. Therefore, optimum values of frequency and amplitude of oscillation were determined on the basis of maximum clod surface produced per unit of energy input. The oscillating tillage tool produced smaller soil aggregates than a non-oscillating one. At a given amplitude of oscillations. increase in frequency above the natural frequency of soil did not increase soil break-up further. At any frequency, soil break-up increased with increase in amplitude. At a tool oscillation frequency equal to the natural frequency of soil the equation MWD=A0exp(-K0r), where MWD is the mean weight diameter of soil aggregates, r is the amplitude of the oscillations, A0 is MWD of soil aggregates produced by an identical rigid tool and K0 is a constant, described the data on soil break up adequately.