INTRODUCING WORMS TO IMPROVE SOIL

Taupo Times, Volume V, Issue 207, 20 January 1956, Page 5

INTRODUCING WORMS TO IMPROVE SOIL

Activity of soil organisms, particularly earthworms, has always been looked on as a sign of good soil fertility, and a trial in which the Department of Agriculture introduced earthworms into South Otago pastures has confirmed this view. In the South Island experiment in the Glenledi district near Milton six colonies of 25 worms of the species Allolobophora caliginosa were placed in a field at points a chain apart in August, 1945, in an 18-month-old sward that was mainly browntop and ryegrass wiith some crested dogstail, timothy, cocksfoot, white clover and red clover. Weeds and bare ground comprised 15 per cent. of the ground cover. Little evidence of worm activity was noted until May, 1949, when the worm-implanted area was noted to be greener and fresher than the nonwormed area and worm casts could be found readily in the vicinity of the liberation points. As ihe worms spread their effect could be noted in the colour, vigour and density of the sward, and when the field was ploughed in spring, 1954, boxwood (Cassinia spp.) and manuka were invading the sward of the nonwormed area. In nine years the six colonies of earthworms had spread over an area of approximately quarter of an acre, on land which had been limed fairly heavily, though the phosphate status was low.