Influence of different mulch treatments on growth rate and activity of the earthworm Eudrilus eugeniae (Kinberg)

Growth characteristics of the earthworm Eudrilus eugeniae and the impac of its activity on soil properties were studied in soil culture. The highest growth rate, fecundity and total weight increase were recorded in cassava mulch, compared with cocoyam mulch, grass and plantain pseudo trunk mulch treatments. With animal manure treatments, growth rate was highest in poultry manure compared with cow and goat manures although total weight increases were highest in poultry and goat manures and lowest in cow manure. The worm activity expressed as percentage reduction of soil bulk density was greatest in cassava mulch followed by grass mulch, cocoyam mulch and plantain pseudo trunk mulch in that order. Various animal manures did not differ in this aspect. Total soil N and soil organic matter increased significantly in cassava and grass mulch treatmens while in plantain pseudo trunk mulch these factors decreased. Soil pH increased in cocoyam and plantain mulch treatments and decreased in cassava and grass mulch treatments.