Nitrous oxide mitigation in UK agriculture

Transcription

1 Nitrous oxide mitigation in UK agriculture Robert Rees, John Baddeley, Anne Bhogal, Bruce Ball, David Chadwick, Michael MacLeod, Allan Lilly, Valentini Pappa, Rachel Thorman, Christine Watson, and John Williams MARCO Workshop on Technology Development for Mitigating Greenhouse Gas Emissions from Agriculture th November 2011

2 Global N 2 O emissions Global N 2 O emissions in the 1990's (Tg N 2 O-N/y) 62% natural 38% anthropogenic Total emissions 17.7 ( ) Tg N/y Denman et al 2007, IPCC

3 Growth in emissions 05/12/2011 Edgar database 3

4 Regional projections Population Current N 2 O emission (Gg) Current per capita emission of N 2 O (g) Projected population growth Projected N 2 O emission 2050 (Gg) Africa Asia Europe Latin America & Caribbean N America /12/2011 4

5 Government targets for greenhouse gas mitigation 679 Mt CO 2 e International aviation & international shipping* UK non-co 2 GHGs Other CO 2 Industrial CO 2 (heat & industrial processes) Residential, public & commercial heat % cut (= 80% vs. 1990) Domestic transport Mt CO 2 e Electricity generation 178 * bunker fuels basis 2007 emissions 2050 objective DEFRA 2009

6 Driving factors of N 2 O production ph mineral N N 2 O production anaerobicity (moisture) available C Factor

7 UK N 2 O emission inventory U. Dragosits, CEH

8 Annual N 2 O emission Management Site Climate 05/12/2011 8

9 Variability in N 2 O emissions between arable sites Ln N 2 O (kg N ha -1 y -1 ) Ht07 Ht08 Nt07 Nt08 Rt07 Rt08-1 Bea El Fou Log Mau Pau Tul Zim 9

10 Management options Ado nt on inputs Imp Us A F Nitri Fertilisation red Precision farming Land use change Regionally optimised plant and animal production Improved timing of mineral fertiliser N application Land drainage Loosen compacted soils / Prevent soil compaction In Burying biochar e feed protein quality f wetlands g cultivars N try manure Peat and Org tion of soil forming conditions Re-locate high N input cropping to drier, cooler areas 10

11 Marginal Abatement Cost Curves Expensive options, small emission savings Financial savings Cheap option, big emission savings Moran et al, Journal of Agricultural Economics, 62, MacLeod et al, Agricultural Systems 103,

12 Management as a mitigation tool Nitrogen input Form/rate Biological inputs Timing Inhibitors Slurries and manures Soil and water management Tillage Irrigation/drainage Crop rotation/agronomy System changes 12

13 NITROGEN INPUT 13

14 Reducing N applications N 2 O ( g N ha -1 d -1 ) g N/ha /04 21/04 05/05 19/05 02/06 16/06 30/06 14/07 28/07 11/08 25/08 08/ IPCC kg N 2 O-N ha Measured DEFRA project Min-No Pappa & Rees, SAC kg N ha -1

15 3.0 N 2 O per unit grain Spring barley Economic Optimum kg N 2 O-N ha kg N ha -1 Cumulative values of N 2 O per fertiliser treatment kg N ha kg N ha -1 Economic Optimum Cumulative values of N 2 O (g) per grain yield of production (t) per fertiliser treatment DEFRA project Min-No Pappa & Rees, SAC kg N ha -1 15

16 Biological N fixation Direct emission factor for N 2 O release from legumes reduced from 1.25% to 0 in 2006 Emissions now restricted to residue inputs Rochette and Janzen 2005, Nutrient Cycling in Agroecosystems, 73,

17 Legumes and nitrous oxide emissions Two mechanisms: Rhizobium sp can produce N 2 O directly Decomposition of plant residues can increase N 2 O emissions N 2 O emission Root and nodule turnover

18 A 4 year FP7 progamme 18 partners, 18 experimental sites (~ 4M) Assess the wider role of legumes in farming systems -Agronomic & environmental criteria -Use of experimental and modelling approaches Design novel legume-based cropping systems for Europe Deliver productive, environmentally-friendly legume-based farming Use a carefully selected network of research staff and experiments

19 Nitrification inhibitors Nitrification inhibitors demonstrate significant mitigation potential DCD treatments of urea plus urine patches Spring Can contribute to lower overall loss, therefore reducing fertiliser input Costs remain high, which limit wider current use Autumn Di and Cameron Soil Use and Management, 19,

20 Cumulative fluxes (gn ha -1 ) Controlled release fertilisers Liquid Sludge Cattle Slurry Compost Sludge Slow Release Zero N Control Julian days from first application Reduce release of available N Can contribute to significant mitigation High costs Ball et al, Soil Use and Management, 20,

21 Manure management and storage Housing Storage Treatment Spreading Chadwick et at, Animal Feed Science and Technology, 166,

22 Slurry and Manure management 6 5 mg N 2 O-N m 2 h control shallow injection surface broadcasting Jul 30-Jul 02-Aug 05-Aug 08-Aug 11-Aug 14-Aug 17-Aug 20-Aug Manure management has a major impact on emissions Method of application can significantly reduce NH 3 emissions but increase N 2 O emissions Chadwick et at, Animal Feed Science and Technology, 166,

23 Fertilised grasslands receiving organic manures Organic N application g N 2 O-N ha -1 d g N 2 O-N ha -1 d Jan 20-Mar 09-May 28-Jun 17-Aug 06-Oct -5 NPK cattle poultry sewage 0-Jan 29-Apr 27-Aug 25-Dec 24-Apr 22-Aug 20-Dec 19-Apr 17-Aug 15-Dec Jones et al Agriculture Ecosystems and Environment,

24 Timing Fertiliser application Jones et al Agriculture Ecosystems and Environment,

25 SOIL AND WATER MANAGEMENT 25

26 Drainage Impeded drainage increases the water filled pore space and denitrification Regional assessments of drainage efficiency are difficult Dobbie and Smith Soil Use and Management, 22,

27 Cumulative N 2 O flux (g N 2 O-N ha -1 ) Reduced tillage No-till No-till Min-till 700 Min-till 700 Normal plough 600 Normal plough 600 Deep plough 500 Deep plough 500 Normal plough compacted /4/08 1/5/08 1/6/08 1/7/08 1/8/08 1/9/ /3/09 20/4/09 21/5/09 21/6/09 Rainfall: May-August 321 mm James Hutton Institute

28 CROP ROTATION A D AGRONOMY 28

29 Low input systems kg N ha -1 y N2O Inputs 300 Leaching Livestock Off-take Seed N BNF 0 Fertilizer N Manure total N Outputs Organic Conventional Organic + CC 3 yr grass 4 yr grass Arable Organic Conventional Atm. deposition -300 Denmark Scotland Sweden 05/12/ Ngoni et al, In preparation

30 Cumulative N2O-N (kg/ha) Cumulative N2O-N (kg/ha) Improved plant varieties Crackerjac k Nitouche Prophet Ragtime Peas Ben Beans Betty Fuego Tattoo 0 28/03/ /05/ /07/ /08/ /10/ /02/200928/03/200917/05/200906/07/200925/08/200914/10/200903/12/2009

31 g N2O-N ha -1 day -1 Species introduction Apr M ay June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May J une July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June Clover/Barley Pea O4/ Barley Pea Nit/barley Barley /05/06 03/07/06 01/09/06 31/10/06 30/12/06 28/02/07 29/04/07 28/06/07 27/08/07 26/10/07 25/12/07 23/02/08 23/04/08 22/06/08-50 Pappa et al Agriculture Ecosystems and the Environment 141,

32 Changing behaviour Rational analysis of mitigation potential does not necessarily lead to change in behaviour Barriers Economic Cultural Educational 32

33 Improving national inventory reporting of emissions 33

34 Conclusions Technologies are available that can contribute significantly to lowering emissions of N 2 O In the UK this could result in GHG savings of between Mt CO 2e y -1 by 2022 Much of this is achieved by increased efficiency We need to understand more about farmer behaviour We urgently need better reporting systems that reflect actual emissions and are sensitive to changes in management 05/12/

35 Acknowledgements UK Government s Department for Environment and Rural Affairs DEFRA-LINK Scottish Government European Union (NitroEurope, Legume Futures) 35