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چکیده
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Earthworms, known as soil engineers, improve soil quality and fertility by affecting the physical (porosity, density and soil texture), chemical (heavy metal adsorption, cation exchange capacity, acidity, soil organic matter and nitrogen concentration) and biological (effect on microbial biota, algal growth and fungal activity) properties of soils. In this study, the effect of urea fertilizer was studied on Eisenia andrei. To evaluate the effect of urea fertilizer on this earthworm, two groups of control and treatment were considered. For each group, a culture medium of 10 liters of washed cow manure was prepared and 20 adult earthworms were placed in each medium. The media were watered daily to maintain moisture. A solution of 0.5% urea fertilizer, in the form of 5 g of urea fertilizer per 1 liter of water, was added to the medium of the treatment group, three times at intervals of 10 days. After 25 days, the condition of earthworms and cocoon production were evaluated. No earthworms or cocoons were observed in the medium treated with 0.5% urea fertilizer solution. In the control group, all adult worms were alive and 4.15 cocoons were produced per adult earthworm. The results showed that the use of urea fertilizer has a severe negative effect on the presence and reproductive activity of the earthworm.
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