摘要
Excess amounts of livestock wastes are excreted in limited area and cause pollution problems in Japan.Comparative studies on livestock waste management among EU(European Union),US(the United States of America)and Asia including Japan are surveyed.In Japan,livestock wastes are mostly separated into solid and liquid matter.Solid matter is converted into organic fertilizer by means of composting.Composting should be developed into the technology that has low emission,high-quality and low cost.Various odorous compounds are emitted from the process of livestock waste management.Odor emission from livestock farms should be mitigated to protect the local community.High-quality compost can be widely distributed to cropland to decrease expenditure of chemical fertilizer.Although liquid matter,namely wastewater or slurry,could be applied to cropland of livestock farms such as EU countries,most of Japanese farms do not have enough cropland to use liquid matter.Particularly pig farms have no area to spread wastewater,which should be purified to clean water in accordance with the criteria of water quality and could be discharged into public water area.The most desirable management of livestock wastes should involve sustainable recycling as compost and environmentally friendly control of odors and wastewater.
