Study of the earthworm population (Lumbricus terrestris) in grassland differing in management

Abstract

This study summarises the occurrence of the earthworm Lumbricus terrestris in differently managed grassland. Experiments were conducted in four sward management systems: long-term sward of seven years of use, perennial grasses in the crop rotation kept for five, three and two years. The ploughed soil layer (13.5 m-2) had the lowest number of earthworms. The number of earthworms ranged from 0 to 28.8 m-2 in the long-term sward, 5.0-20.0 m-2 in the sward used 5 years, 0-36.2 m-2 in the sward used three years and 5.0-12.5 m-2 in the sward used two years. The occurrence of earthworms was most markedly affected by the moisture content of freshly ploughed soil. A lesser effect was exerted by the soil undisturbed for three years. The effect of moisture in soil undisturbed for five years on the occurrence of earthworms was weak, and no effects were identified in the soil undisturbed for 18-24 years. Legumes had a positive effect on the occurrence of earthworms when the swards were used for three years (Trifolium pratense) and five years (Trifolium repens). It should be noted that in the sward of five years of use, Lolium perenne accounted for the largest share of grasses (34.9%).