The influence of earthworms on nutrient dynamics during the process of vermicomposting

Abstract

In the present study the potential of the earthworm Eisenia andrei to modify chemical and microbiological properties, with a special focus on the nutrient content of fresh organic matter, was evaluated during 16 weeks of vermicomposting of cattle manure and sewage sludge. Samples were periodically collected in order to determine the changes in inorganic nitrogen (N), in total microbial biomass and activity, as well as in the total and available content of macro- and micronutrients. An optimal moisture level, ranging from 75% to 88%, was maintained throughout the process. The content of organic matter decreased over time, but no changes were found in this parameter as a result of earthworm activity. The carbon/N ratio rapidly decreased, but only in the manure, reflecting rapid decomposition and mineralisation of the organic matter by the earthworms. An increase in N mineralisation was also attributable to the presence of earthworms, although in the manure this effect was hardly detectable before the eighth week of vermicomposting. Earthworm activity also enhanced the total content of potassium, calcium and iron together with an increase in the availability of phosphorus and zinc. We did not detect a significant earthworm effect on microbial respiration, but their activity increased greatly microbial biomass nitrogen in sewage sludge.

A potential bioconversion of empty fruit bunches into organic fertilizer using Eudrilus eugeniae

“…It is hypothesized that fungal and microalgal hyphae, which easily colonize on freshly deposited worm casts, are contributing to trace level of magnesium in the final vermicompost (Suthar 2010b;Lim et al 2012). Domínguez and Gómez-Brandón (2013) found that the presence of earthworms increased total magnesium content in the solid wastes over time but this effect was more obvious in the manure rather than sewage sludge. Also, Lim et al (2014) found that the final vermicomposts which were derived from palm oil mill effluent after 6 weeks of vermicomposting had higher total magnesium contents when rice straw (rather than soil) was used as an amendment.…”

“…Figure 7 shows that the maximum increases in total magnesium content in the final vermicomposts were obtained from the treatments of E2:D1 (?370.93 %), followed by E3:D1 (?245.36 %), E1:D2 (?206.10 %), E1:D3 (?163.60 %), E1:D1 (?83.58 %) and E (?55.86 %). Some recent studies also indicated that the final vermicomposts contained higher total magnesium content after the earthworms were incorporated into biodegradation process of solid wastes (Domínguez and Gómez-Brandón 2013;Lim et al 2014). Until now, the direct contribution of earthworm in magnesium metabolism is still unclear.…”

Toprak Solucanları ile Kompostlaştırılmış Tütün Atıklarının Vermikompost Olarak Değerinin Belirlenmesi

“…Ortalama değerler dikkate alındığında ise vermikompostlamanın tütün atığının CO 2 -oluşumunu arttırdığı, TA+AG vermikompostu üzerine ise herhangi bir etkisinin olmadığı anlaşılmaktadır. Dominguez and Gomez-Brandon (2013) yaptıkları çalışmada arıtma çamuru ve ahır gübresinde ortaya çıkan CO 2 -oluşumu üzerine vermikompostlamanın bir etkisinin olmadığını saptarlarken, Pramanik et al, (2009) sığır gübresi ve çim atıklarından yapılan vermikompostalama sonucu mikrobiyal solunumun arttığını belirlemişlerdir.…”

Earthworms and Vermicomposting

“…Vermicomposting, the transformation of organic waste into vermicompost, is a biooxidative mesophilic process in which detritivorous earthworm species interact with microorganisms, strongly affecting decomposition processes, accelerating the stabilization of organic matter, and greatly modifying its physical, chemical, and biological properties [1][2][3][4]. Vermicomposting and vermiculture are well established worldwide and are important for economic and environmental reasons [5].…”