Wj. Meyer et Gc. Loots, The influence of anisopary on a population of Eisenia fetida in a bed and flow-through system, PEDOBIOLOG, 43(6), 1999, pp. 760-765
Many commercial practices for vermiculture have been developed. The convers
ion rate of organic material through the worms is directly inline with the
number of worms in the system. Beds and continuous flow systems are widely
used commercially in many countries. In South Africa both systems are used
with varying results and for different applications. A difference in the po
pulation reproductive capacity of beds and containers (flow-through) have b
een noticed and were studied. In this study both systems were fed with the
same organic material before the experimental period and during the experim
ental period. Eighty-four clitellate individuals from each system (bed - an
d a container systems) were used in the study. The hatchlings were counted
and removed over a 90 day period. The experiment was conducted outdoors in
commercial conditions. The earthworms from the bed system reproduced at nor
mal levels, Anisopary was observed as follows: 38 % hypoparous and 62 % hyp
erparous.
The earthworms from the containers hardly kept the population number stable
. Anisopary was observed as follows; 91 % hypoparous and 9 hyperparous. Hyp
opary worms (male functioning) were dominant in the container population. T
his was probably due to population stress in the containers. This factor ma
y influence the life span of container populations and vermicompost product
ion in the long run. The conversion rate of organic material was not affect
ed during the study period. The question arises whether such populations ca
n be sustainable for long periods or should be supplemented to keep up conv
ersion rates in commercial projects.