EVALUATION OF VERMICOMPOSTED CATTLE MANURE

Vermicompost (lumbripost, biohumus) is organic fertilizer or potting medium produced by microbial decomposition of cattle manure using Californian earthworm (Eisenia foetida). Analysing physical, chemical and biological properties confirmed that the vermicompost was stable with significant level of plant nutrients and the concentration of analysed heavy metals below threshold values. The results of vermicompost analyses were 17.85% ash, neutral pH reaction, EC 1.07 dS m-1, 24.6% total C, 2.32% total N and C:N ratio 10.6 indicating vermicompost maturity. Analyses showed significant concentrations (in g kg-1) of total P (11.25), K (6.13), Ca (10) and Mg (8.55) and microelements (in mg kg-1) Fe (9464), Mn (354), Zn (272) and Cu (46). Also, the total concentration of Zn, Cu, Pb (16 mg kg-1) and Cr (42 mg kg-1) was below permitted threshold values indicating that the use of vermicompost as fertilizer or as potting medium would be unrestricted. Biological tests show that (i) the vermicompost was stable because measured respiration rate was 1.2 mg CO2-C g-1compost-C day-1, and (ii) the vermicompost did not show any phytotoxic effects because the 14-day growth of lettuce in containers resulted in higher aboveground fresh matter production using vermicompost as a potting medium compared with commercial medium, although the differences were not statistically significant.