Studies on the Relationships Between Earthworms and Soil Fertility: I. Biological Studies in the Field

Abstract

Changes in the seasonal activity of several species of earthworms have been followed in a permanent pasture field for 18 months, 1945-6. The two soil conditions which chiefly determine activity are temperature and moisture. Other factors are the occurrence of an obligatory diapause in the two species Allolobophora n o c t m and A. longa, and changes in population in A. chlorotica and Lumbricus terrestris.Soil temperature and soil moisture also determined the weight of soil thrown up in the form of wormcasts during autumn, winter and spring. It is suggested that only two species, A. nocturna and A. longa, are responsible for wormcasts and that the other four common species present play little or no part in this activity.At Rothamsted it was found that the previous agricultural history of the field is an important factor in determining the fauna. Old permanent pasture is characterized by a high percentage of A. nocturna and a rather lower percentage of A. caliginosa. Ploughing old permanent pasture and reseeding to grass after I or z years arable reduces the proportiom of A. nocturna and A. caliginosa and increases that of Eisenia rosea. 4rable fields have A. chlorotica as the dominant species and pasture fields z7years grass after many years of arable farming still show a high percentage of A. chlorotaka and a low proportion of A. nocturna.A survey of the Carse of Stirling, Scotland, showed that soil type is also an important factor in determining the earthworm fauna. A. cdgfmsa was the dominant species on the three soil types studied, but the subdominant species varied. On clay soil, A. longa was subdominant; on loam, A. longa and L. d e l l u s ; on sandy soil, A. longa, L. rubellus and A. chlorotica. The dominant species of pasture land at Rothamsted, A. nocturna, was not found at Stirling.

Pore morphology changes under tillage and no-tillage practices

“…In June, mechanical fragmentation and natural settling have already occurred (Mackie-Dawson et al, 1989). Optimal burrowing activity is most pronounced in spring and autumn when the soil water content increases (Evans and Guild, 1947) but earthworm burrowing activity displacements are facilitated by ploughing. The images obtained under conventional tillage between June and September show the obvious action of earthworms with the presence of cashes within burrows (Fig.…”

The development of sustainable earthworm populations at Calvert landfill site, UK

“…Therefore, sampling could only proceed by means of either surface-cast observation (e.g. Evans and Guild, 1947) or through digging and hand-sorting of the cap, followed by vermifuge addition (e.g. Edwards and Bohlen, 1996).…”

“…To estimate the furthest distance that this species had colonized since inoculation, a systematic visual search was employed and all castings found were used to signify the presence of A. longa (Evans and Guild, 1947). To verify the presence of A. longa, the areas directly below a proportion of the castings were excavated.…”

Action of earthworms on flint burial – A return to Darwin’s estate

“…However, results obtained do mirror those of Evans and Guild (1947) as an index of earthworm activity across the year in Southern England. Differing management of GHM compared with GPM may not be significant, given similar numbers and biomasses of casting lumbricid species in both (Butt et al 2008) but ideally data would have been collected directly from GPM.…”