Abstract:

In order to solve the environmental sanitation and soil pollution caused by livestock manure in southern Ningxia, this study used “Daping 2” earthworm to treat cattle manure, and then explored the effect of earthworms feeding on mixture of cattle manure and corn stalk in different proportions by laboratory measurements. The results showed that vermicompost was loose, had distinct granular structure and no bad smell. The average bulk density of vermicompost was 0.39 g/cm³. The average total porosity, capillary porosity and non-capillary porosity were 85.85%, 62.86% and 22.99%, respectively. The air permeability and water permeability of vermicompost were obviously improved. Total water soluble salt and pH decreased, and their properties tended to be neutral. Compared with fresh cattle manure, contents of organic matter, total nitrogen, total potassium and C/N decreased by 62.6%-69.8%, 41.1%-49.0%, 20.7%-33.2%, 34.3%-47.8% respectively, while content of total phosphorus increased by 1.3-2.0 times. Adding appropriate amount of corn stalk helped to improve the quality of vermicompost organic fertilizer. Earthworm treatment accelerated the decomposition of cellulose, hemicellulose and acid detergent ligninin of cattle manure, their contents decreased by 74.0%-77.5%, 65.6%-83.1% and 5.2%-16.3% respectively. The removal efficiency of Cu, Zn by the treatment was better than that of Pb and Cr. The conversion efficiency of cattle manure by earthworms was 43.42%-65.15%, and the conversion efficiency could be improved by adding corn stalk. Local farmers can use earthworms to transform livestock and poultry manure such as cattle dung, improve the comprehensive utilization rate of manure and reduce environmental pollution.

Key words: earthworm, cattle manure, livestock manure, corn stalk, vermicompost