EFFECTS OF EARTHWORM APORRECTODEA-CALIGINOSA ON SOME FACTORS IN DIFFERENT SOIL CULTURES

The earthworm Aporrectodea caliginosa was kept in the laboratory in Qatar in four types of soil: light loam, clay loam, sandy loam and sandy for three months. Factors including pH level, organic matter, nitrogen, microelements and microorganisms were measured before and after the introduction of the earthworm to the various soils. Considerable alteration in several of these factors was observed three months after the introduction of the earthworm. Seasonal changes in earthworm populations have been studied and the optimal environmental factors for earthworm survival is suggested.