China’s rapidly growing demand for food and energy puts heavy pressure on its limited natural resources and causes degradation of the local environment at unprecedented rates. To provide sufficient food, China has been following a trend of agricultural production intensification characterized by high N fertilization rates and rapid introduction of industrial livestock production units in the vicinity of urbanized areas. This trend profoundly disturbs the natural nitrogen and carbon balance, due to either leaching of excess N compounds into ground water and river systems, or volatilization into the atmosphere of greenhouse gases and other pollutants.

With regards to global climate change, agricultural land use and management for crop and livestock production cause significant emissions of CH4 and N2O gas into the atmosphere. With regards to regional human and ecosystem health, excess leaching of nitrogen into ground water and rivers as well as volatilization of NH3, N2 and NOx  contribute to regional and local air quality problems such as acidification and eutrophication of ecosystems, and cause damage to human health via the exposure to high PM2.5 concentrations. Increasing demand for bio-energy in coming decades may further exacerbate environmental pressures. At the same time, agricultural productivity is under threat from climate change in many regions, and adaptation measures will be implemented to limit production risks.

In view of this dilemma, the project explores how China could manage its nitrogen use for agricultural activities in the coming decades in such a way that demands for agricultural products are satisfied while negative impacts on the local environment are minimized.

Project integrated demand-driven agricultural modeling (CATSEI model) and simulations of the nutrients fluxes to air and water (GAINS model and MITERRA model, respectively) to explore the relationship between agricultural demand, production and impacts. The drivers and trends of agricultural intensification are used to compile indicators of leaching, nitrous oxide and ammonia release into the environment in China. This allows to assess the magnitude of environmental loads and humans exposure to health risks under alternative demographic or socio-economic scenarios. The integrated methodology permits to gain insights regarding the current and future situation of the indicators at the level of Chinese counties. Project develops a number of alternative policies to modify agricultural practices in order to mitigate nitrogen spills into the environment:

• Business-as-usual allocation scenario
• Sustainable reallocation scenario
• Optimizing fertilizer use scenario (first apply manure; only match rest of the demand with mineral fertilizer)
• Minimized ammonia scenario based on advanced technology options

The scenarios show that the underlying demand leading to nitrogen pressure on the Chinese environment will still increase, due to considerable increases in food demand (population growth is still to continue, coupled with increased meat share, which adds to the nitrogen requirement). In the baseline, increases of leaching are expected to be stronger (more than 50% increase between 2000 and 2030) than those of gaseous emissions. But options are available that are expected to considerably improve the current situation and revert the trend. Again especially leaching would be affected, about halving the current release of nitrate, while gaseous emissions would remain at a level comparable to now. Optimization needed anyway to reduce air and water pollution may at the same time cut soil emissions of the greenhouse gas N2O by 25%, clearly indicating a win-win situation as negative interactions between environmental pools can be avoided.
Comparing the resulting emissions of nitrous oxide for the historic situation with available information from much more detailed Chinese studies indicates that the estimate developed here, although somewhat higher than figures found in literature, is clearly within the margins of uncertainty. This provides further confidence in their use as indicators.

Relevant publications:

1. Fischer, G., Ermolieva, T., Ermoliev, Y., van Velthuizen, H. (2006). Livestock production planning under environmental risks and uncertainties. Journal of Systems Science and System Engineering, 15(4), 385-399.
2. Ermolieva T., G. Fischer, and H. van Velthuizen (2005). Livestock Production and Environmental Risks in China: Scenarios to 2030”, FAO/IIASA Research Report, International Institute for Applied Systems Analysis, Laxenburg, Austria.
3. Ermolieva, T., Winiwarter, W., Fischer, G., Cao, G.-Y., Klimont, Z., Schöpp, W., Li, Y., Asman, W.A.H. (2009). Integrated nitrogen management in China. IIASA Interim Report IR-09-005, International Institute for Applied Systems Analysis, Laxenburg, Austria.
4. Fischer G., Ermolieva, T., Cao, G.Y., Zheng, X.Y., Wiberg, D., Winiwarter, W., Klimont, Z., Toth, E. (2008a). Measuring and Mitigating Environmental Risks from Agriculture, submitted to the special issues of peer reviewed papers presented at IIASA-Peking University Symposium on Urbanization and Environment
5. Fischer G,  Ermolieva T,  Ermoliev Y,  Sun L  (2008b). Risk-adjusted approaches for planning sustainable agricultural development. Stochastic Environmental Research and Risk Assessment, 1-10.
6. Fischer G,  Ermolieva T,  Ermoliev Y,  Sun L  (2007). Integrated risk management approaches for planning sustainable agriculture. In C. Huang, C. Frey, J. Feng (Eds.), Advances in Studies on Risk Analysis and Crisis Response. Atlantis Press, Paris, France.
7. Fischer, G., Ermolieva, T., Ermoliev, Y., and van Velthuizen, H. (2006) Sequential downscaling methods for Estimation from Aggregate Data. In K. Marti, Y. Ermoliev, M. Makowski, G. Pflug (Eds.), Coping with Uncertainty: Modeling and Policy Issue. Springer Verlag, Berlin, New York.

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Last updated: 16 Oct 2009