A note on the reduction of runoff from crusted soils by earthworm burrows and artificial channels

Abstract

AbstractThe aim of this study was to determine the order of magnitude in which earthworm channels can contribute to the reduction of runoff during simulated rainfall. Two sets of experiments were carried out, the first using soil columns (Ap‐horizon of a Luvisol) in which endogeic earthworms had dug channels through previously produced surface seals, the second set consisting of runoff boxes, where artificial channels were made with a needle following a rainfall application that had also produced a pronounced surface seal.In all cases, the persistance of open earthworm burrows led to a considerable decrease in runoff. It was observed that channels smaller than 5 mm in diameter were resealed within the first 15 minutes of rainfall, and did not contribute to percolation in the experiment with soil columns. In the experiment with the runoff boxes, a highly significant correlation was found between number of open channels and runoff rate, the treatments with a slope of 5% and a rainfall intensity of 30 mm/h showing a greater effect when compared to the treatment with 10% slope and an intensity of 60mm/h.