MAGGE-PH

Mitigating Agricultural Greenhouse Gas Emissions by improved pH management of soils

Climate forcing by crop production is dominated by N2O emissions. Although emissions can be marginally reduced by “good agronomic practice”, we need more targeted approaches to make progress. For that, MAGGE-pH concentrates on the microbial processes responsible for production and consumption of N2O in soils. Our point of departure is the emerging understanding of how soil pH perversively controls the N2O/(N2O+N2) product ratio of denitrification. Since denitrification is the dominant source of N2O, this indicates that N2O emissions from cultivated soils can be reduced substantially by increasing the pH of moderately acidic soils beyond that needed to secure adequate crop growth. This necessitates policy instruments to secure effective implementation, and MAGGE-pH will deliver socio-economic analyses to identify such instruments.

The evidence for the pH effect on N2O emissions stems almost exclusively from laboratory experiments. Now we need stringent testing of different liming strategies under realistic field conditions. This will be the core activity in MAGGE-pH and generate emission factors for a range of N fertilizers / manure / urine / biochar applications explicit for soil pH. We will also explore the use of non-calcareous rock powders as a replacement for traditional limes (carbonates). This is highly relevant, because CO2 emissions from carbonates can negate their potential GHG reducing effect. MAGGE-pH will also explore novel approaches to manage soil pH via fertilizers and manure, in order to reduce both N2O emission and NH3 volatilization. Thus, the project adds some "blue sky” research to the core objectives and puts it to the critically evaluation by a broad European consortium consisting of researchers, fertilizer companies and practitioners.


Coordinator

Norwegian University of Life Sciences, Norway

Dr. Peter Dörsch
Email: peter.doersch[at]nmbu.no


Project partners

National University of Ireland, Galway, Ireland

Teagasc, Ireland

Aarhus University, Denmark

Thuenen Institute, Germany

Swedish University of Agricultural Sciences, Sweden

University of Helsinki, Finland

Institut National de Recherche en Agronomie (INRA), France

University of Otago, New Zealand

Natural Environment Research Council, United Kingdom


Total requested funding

2.269.000 €


Project duration

36 months