Nitrogen is an essential nutrient for food production. Still, its excessive utilization has a significant impact on multiple environment pollution threats, including air pollution, eutrophication of lakes and enclosed seas, and groundwater pollution. Toward sustainable nitrogen management, it is important to grasp the holistic material flow of nitrogen and the balance of input and output, and then consider effective measures.
Japan imports almost all of its raw materials for major chemical fertilizers, as well as nitrogen compounds in various forms such as ammonia. Much of the nitrogen produced and imported is not used effectively and is discharged into the water and atmospheric environment for loss. Currently, we are working on the improvement of nitrogen budgets and inventory, and based on these, we would like to develop a recycling system of nitrogen resources.
Achivements and challenges of nitrogen management in Japan
In the 1950s and 60s, heavy environmental pollution caused by population growth and rapid economic growth was a severe problem in Japan. Since then, Japan has been taking various measures, including the Air Pollution Control Act and the Water Pollution Control Act, setting standards for exhaust gases such as nitrogen oxides as well as wastewater standards for nitrate and nitrite nitrogen. As a result of these efforts, we carried out significant improvements in air and water environment.
However, there are some challenges remained. In some areas, the concentration of nitrate and nitrite nitrogen in groundwater and total Nitrogen in lakes do not achieve environmental standards, yet. On the other hand, in recent years, the impact of nutrient shortages on fishery resources has become an issue in enclosed seas. In addition, as a climate change mitigation measure, the use of ammonia as fuel is expected to increase in the coming years. It is necessary to balance with reducing emissions into the atmospheric environment. Since the issues of nitrogen management vary from region to region, it is necessary to act according to the condition of the each region.
National action plan for sustainable nitrogen management
Nitrogen management is a challenge not only for the environment conservation, but also for various sectors such as agriculture, fisheries, infrastructure, and industry. Thus, interministerial coordination and cooperation are inevitable. Based on UNEA resolution on sustainable nitrogen management, Japan holds the relevant ministries liaison meeting since last year, in order to facilitate communication, information sharing and discussions among relevant ministries toward the formulation of the national action plan for sustainable nitrogen management. In addition, we also hold the advisory committee on sustainable nitrogen management to obtain scientific and technical advice and deepen the discussions.
Synergistic approach on nitrogen management
Synergistic approach is also effective for nitrogen management. For example, using livestock manure for energy contributes to water quality improvement and decarbonization. Nutrient management in enclosed seas conserves marine fishery resources and contributes to nature positive. Japan will promote the synergistic approach on nitrogen management, synergistically achieving water and atmospheric environment improvement with carbon neutral, circular economy, and nature positive.
International cooperation
In addition, toward the sustainable nitrogen management globally, international and regional cooperation is also significantly important. Japan has several programs, such as sharing knowledge and experience and promoting capacity building through the Acid Deposition Monitoring Network in East Asia (EANET) and Water Environment Partnership in Asia (WEPA) and supporting introduction of technologies by the model projects.
In particular, EANET has been monitoring wet and dry deposition, soil, vegetation, land water, and catchments for many years, accumulating a lot of data on reactive nitrogen. Japan held seminar on sustainable nitrogen management as the EANET project in just five days ago, to share international trends, knowledge and experience of EANET to raise awareness in Asia region. To take early action, it is necessary to make effective use of such existing regional organizations and programs.