Risk Assessment of Livestock Manure in Meizhou Area of Guangdong

The total volume of manures of all species of livestock in Meizhou was estimated using the excretion coefficient method, and the maximum animal manure loading capacity of the field was calculated, for environmental risk assessment of the industry based on pre-warning values of animal manure loading capacity of farm fields. Results show that the industry in Meizhou turned out 324.60×10⁴ t of excrement and 180.02×10⁴ t of urine, which included 19.36×10⁴ t of BOD₅，19.91×10⁴ t of COD, and 2.423×10⁴ t of NH₃-N in 2008. The average livestock manure loading capacity of the field reached 23.07 t • hm^-2 • a^-1. The averaged livestock manure loading early-warning value was 0.51, which could be sorted into Grade II of the overall early-warning, corresponding to “slight environmental pollution”. However, it varied from area to area. Fengshun County was the highest in early-warning value. Pingyuan County was much lower, thus giving the county much room for development of its livestock production.