Customizing Provincial Sustainable Manure Management Strategies for Small‑, Medium‑, and Large-Scale Cattle Farms in China

Large-scale cattle farming currently accounts for only
30% of the
industry in China, where significant variation in farm sizes and distributions
poses challenges to sustainable manure management. Moreover, substantial
gaps exist in research on the environmental impacts of manure treatment
technologies across different farm scales. The environmental and economic
performances of eight different cattle manure management techniques,
including six aerobic, three anaerobic, and integrated methods, were
evaluated for small, medium, and large cattle farms using life cycle
assessment and life cycle cost methods. The results indicate that
the black membrane biogas pool (BMBP) offers the best environmental
and economic benefits, reducing the global warming potential (GWP)
by 101.3% and enhancing the profit by at least 148.7 CNY per ton of
dry cattle manure. Significant disparities in cattle farming scale
and manure production across provinces necessitate region-specific
policies. The GWP from national cattle manure management stands at
about 1.3 million tons of CO2 equiv, with major inputs
from Sichuan, Yunnan, and Inner Mongolia, comprising 25.2% of the
total. Increasing the utilization rate of cattle manure from 80% to
90% by 2025 could reduce the GWP by 11.0%. Advancing the BMBP and
shifting 5% of aerobic to anaerobic processes could reduce carbon
emissions by 0.2 million tons of CO2 equiv and other pollutants
by 1.1–23.4%. Therefore, enhancing anaerobic technology and
boosting utilization rates promise more efficient and synergistic
reductions in CO2 emissions and other pollutants.