Vermicomposting of wastes from hazelnut shell and diary industries with eisenia foetida: A small-scale study

In this study vermicompost was produced by Eisenia foetida using mix of certain ratios of nut shell (NS) and cow manure in lab conditions. The experiments were conducted according to randomized complete block design with three replicates in a lab in Sakarya, Turkey for 4 months. Five different treatments (NS90M10; NS75M25; NS50M50; NS25M75; NS10M90) were tried in special containers with lids together with 250 Eisenia foetida worms for each trial. Distilled water was used for humidification. pH, EC, humidity, organic matter, total humic+fulvic acid, total nitrogen, total organic carbon (TOC), total P, dissolved K, Mg, Ca Fe, Mn, Zn and Cu were analyzed for each 5 trials at the end of the experiment. Moreover, worms were counted and changes over time were determined. The highest average N, P, K, Ca, Mg, Fe, Mn, Zn and Cu percentages were obtained as 1,75; 0,38; 1,12; 1,7; 0,38; 0,12; 0,01; 0,01 an 0,004 %, respectively in the trial with the highest ratio of cow manure (NS10M90), and the lowest of these measurements were obtained in the trial with the highest ratio shell (NS90M10). The average pH, EC, and humidity were found to be 7,64; 964,51 µS/cm and 67,73%, respectively. The highest organic matter content (41,11%) and TOC content (41,23%) was obtained from NS90M10, and the highest humic+fulvic acid content (25,89%) was obtained from the trial NS10M90. The C:N ratio which is desired to be low for vermicompost was obtained as highest from NS90M10 trial, and lowest from NS10M90 as 101,67 and 19,43, respectively. The differences between each parameter were found to be statistically significant (p<0,01). The highest average earthworm count on the last day of the experiment was 258 in the NS25M75 trial and it was only 8 earthworms more than the starting count.