Growth, reproduction and vermicompost production of the African red worm (Eudrillus eugeniae) in precomposted bovine manure

Abstract

Bovine manure is one of the main sources of pollution in agricultural systems, due to the emission of greenhouse gases, the proliferation of pathogens and the accumulation of nutrients that can affect soils and bodies of water. Its use through biotechnological processes such as vermicomposting offers a sustainable alternative to transform this waste into a resource of high agronomic value. From this perspective, the influence of bovine manure with and without pre-composting on the growth, reproduction and production of the African earthworm (Fudrillus eugeniae) was evaluated at the Guadalupe farm of the Antonio de Valdivieso International University in the department of Rivas, in southern Nicaragua, from March to June 2024, under a completely randomized design, with two treatments and four replications (eight experimental units); 100 adult earthworms were placed for the adaptation period and 85 for the study in each experimental unit and were fed every seven days according to the daily consumption of the earthworms. During the pre-composting period (7 days), the manure was turned daily, and its temperature, humidity, and pH were monitored. In each experimental unit, 10 earthworms were randomly selected for length and weight measurements. The remaining variables were evaluated in 100% of the substrate. An analysis of variance and mean separation using Fischer's least significant difference test were performed with a 5% margin of error. Pre-composting of fresh manure did not significantly affect earthworm length or vermicompost production. However, it did have a temporary effect on biological variables such as weight gain, number of cocoons, reproduction rate, and earthworm population, promoting increases in initial stages that tended to decrease in later phases of development. This process did not generate substantial variations in most of the evaluated parameters; however, an increase in phosphorus availability and, more notably, in calcium content was observed.