Emission Rate of Greenhouse Gases from Bedding Materials of Cowshed Floor: Lab-scale simulation study

摘要

To know the emission amount of greenhouse gases from bedding materials of cowshed floor, the emission rates of methane (CH4) and nitrous oxide (N2O) gases from a simulated cowshed floor (SCF) with sawdust that manure loading rate into the bedding material could be accurately controlled were assessed in this study. The manure loading rates of Korean beef and Holstein dairy cattle into the SCF of 0.258 m~2 surface area with 10 to 15 cm height sawdust were 1.586 kg/m~2/d and 3.588 kg/m2/d, respectively,and those were calculated on the basis of “Standard model for sustainable livestock” and “Data for excretion amount of manure from livestock”. All experiments were done in triplicates in three different seasons (May to July, Sep. to Nov., and Feb. to Apr.) using 12 SCFs. The effects of bedding material thickness on CH4 and N_20 emission from SCFs for both Korean beef cattle and Holstein dairy cattle were not statistically significant (p<0.05). Emission amount of CH4 and N2O per square meter of SCFfor Holstein dairy cattle was 7.5 and 1.2 times higher than that of Korean beef cattle, respectively. The yearly CH4 amount per head was 17.7 times higher in Holstein dairy cattle, obtaining 130.4 g/head/year from SCF for Holstein dairy cattle and 7.4 g/head/year from SCF for Korean beef cattle, and N2O was also 3.8 times higher in Holstein dairy cattle (3,267 g/head/year in Korean beef cattle and 14,719 g/head/year in Holstein dairy cattle). However, the N_20-N per loaded nitrogen into SCF was higher in Korean beef cattle, having 0.2148 and 0.1632 kg N_20-N/kg N in Korean beef cattle and Holstein dairy cattle, respectively, and those values were 3.07 and 2.33 times higher than that of Intergovernmental Panel on Climate Change (IPCC) 2006 guideline (GL) (0.07 kg N_20-N/kg N).