Earthworm Population Studies : a Comparison of Sampling Methods

Abstract

SVENDSEN¹ showed that the estimate of an earthworm population obtained by hand sorting soil samples was much greater than that by the prevalent method of bringing worms to the soil surface with potassium permanganate solution, and so emphasized that, although laborious, hand sorting was more accurate for population studies. The accuracy of estimates by hand sorting has not been studied but is likely to depend on soil type and conditions, as well as on the time and care taken to examine the sample. One way to estimate accuracy is to see how many worms can be recovered when samples, already hand sorted, are examined again by a different method.