Infiltration and random roughness of a tilled and untilled claypan soil

No-tillage is generally assumed to increase infiltration and reduce runoff, but runoff from a claypan soil in Central Missouri, however, was greater from no-tillage plots than from moldboard plowed plots. The effect of simulated rainfall on infiltration and random roughness of tilled and untilled soil was measured. Four different tillage systems, each with and without surface cover were studied. An exponential decay function describes the change in random roughness for tilled soil exposed to rainfall kinetic energy. Although the differences were not statistically significant, among the uncovered tilled plots those with the highest random roughness had the highest infiltration. The bare no-tillage treatment had the lowest infiltration. Plots protected with shredded foam rubber infiltrated 88–248% more rainfall than similar bare plots.