Indirect N 2 O emissions: Model-based quantification of N leaching and NH 3 emissions in OSR fertilized with mineral and organic fertilizers

Transcription

1 Indirect N 2 O emissions: Model-based quantification of N leaching and NH 3 emissions in OSR fertilized with mineral and organic fertilizers T. Räbiger U. Böttcher H. Kage Crop Science & Plant Breeding CAU Kiel Germany

2 1 Outline Introduction Indirect N 2 O emissions from NO 3 leaching Indirect N 2 O emissions from NH 3 volatilization Total specific GHG emissions from OSR cultivation Conclusion & Outlook

3 Use of rapeseed oil within the EU 12'000 in t Food 10'000 Biofuel 8'000 6'000 4'000 2'000 '0 Source: FAPRI, AMI 2

4 Greenhouse gas emissions EU Renewable Energy Directive: GHG emission reduction goal for biofuel 3

5 Greenhouse gas emissions EU Renewable Energy Directive: GHG emission reduction goal for biofuel Nitrous oxide (N 2 O) from arable land Major contribution to global GHG balance 3

6 Greenhouse gas emissions EU Renewable Energy Directive: GHG emission reduction goal for biofuel Nitrous oxide (N 2 O) from arable land Major contribution to global GHG balance Direct N 2 O: measured at place of origin 3

7 Greenhouse gas emissions EU Renewable Energy Directive: GHG emission reduction goal for biofuel Nitrous oxide (N 2 O) from arable land Major contribution to global GHG balance Direct N 2 O: measured at place of origin Indirect N 2 O: result of displaced reactive N compounds by: Ammonia (NH 3 ) volatilization Especially after organic fertilizer usage Nitrate (NO 3 2- ) leaching 3

8 4 Specific GHG-emission fertilizer production direct N2O [gco 2 -eq./mj] indirect N2O leach 11.9 indirect N2O volat OSR production: 180 kg N (CAN) 4.3 t ha -1 (DM)

9 5 Calculation rules for biofuel GHG emissions in Europe (following IPCC) Direct N 2 O emission: 1% of N input (fertilizer + crop residues) Indirect N 2 O emisson: Ammonia volatilization Mineral: 10% of total fertilizer-n Organic: 20% of total fertilizer-n 1% of ammonia volatilization as indirect N 2 O N-leaching: 30% of N input (fertilizer + crop residues) 0.75% of N leached as indirect N 2 O

10 6 Oilseed rape: characteristics High N uptake (until flowering) High N content in plant residues Fast mineralization N leaching potential! Typical crop rotation: Winter barley - OSR - Winter wheat Low N uptake by wheat before winter N leaching potential!

11 7 Outline Introduction Indirect N 2 O emissions from NO 3 leaching Indirect N 2 O emissions from NH 3 volatilization Total specific GHG emissions from OSR cultivation Conclusion & Outlook

12 Experimental sites & treatments Hohenschulen (HS) 760 mm a -1 ; 8.8 C (longterm avarage) Pseudogleyic sandy loam (Luvisol) OSR yield: 4.1 t ha -1 Berge 500 mm a -1 ; 8.7 C (longterm avarage) Sandy loam (Cambisol) OSR yield: 3.4 t ha -1 Treatments: 0 kg N ha -1, 180 kg N ha -1 (CAN), 180 kg NH 4 -N ha -1 (org) 8

13 Quantifying N leaching Simulation model: Dynamic crop growth submodels (OSR; Wheat) specific N Uptake 9

14 Quantifying N leaching Simulation model: Dynamic crop growth submodels (OSR; Wheat) specific N Uptake 5 pool coupled C and N model Input of organic matter into DPM and RPM N mineralization 9

15 Quantifying N leaching Simulation model: Dynamic crop growth submodels (OSR; Wheat) specific N Uptake 5 pool coupled C and N model Input of organic matter into DPM and RPM N mineralization Dispersion convection model + layered soil water model Nitrate (NO 2-3 ) movement NO 2-3 transport below rooting zone of OSR N leaching 9

16 Quantifying N leaching Simulation model: Dynamic crop growth submodels (OSR; Wheat) specific N Uptake 5 pool coupled C and N model Input of organic matter into DPM and RPM N mineralization Dispersion convection model + layered soil water model Nitrate (NO 3 2- ) movement NO 3 2- transport below rooting zone of OSR N leaching Simulation run: harvest of preceding crop - end of wheat tillering 9

17 soil water content [cm³ / cm³] Soil Mineral N [kg N ha -1 ] 10 Goodness of fit SMN and WC Jul-12 Oct-12 Jan-13 Apr-13 Aug-13 Nov-13 Feb-14 period Jul-12 Oct-12 Jan-13 Apr-13 Aug-13 Nov-13 Feb-14 period

18 Model output: Hohenschulen 2013 CumNUptake CumNUptake kg N ha OSR Wheat CumNUptake = cumulated N uptake by OSR and wheat NSupplyOrg = cumulated supply of N via organic matter Sum SMN = time course of mineral N in soil profile (0-0.9 m) CumNLeach = Sum of leached NO 3 2 N 180 kg NH 4 -N ha -1 (org) 11

19 Model output: Hohenschulen 2013 CumNUptake NSupplyOrg kg N ha OSR Wheat CumNUptake = cumulated N uptake by OSR and wheat NSupplyOrg = cumulated supply of N via organic matter Sum SMN = time course of mineral N in soil profile (0-0.9 m) CumNLeach = Sum of leached NO 3 2 N 180 kg NH 4 -N ha -1 (org) 11

20 Model output: Hohenschulen 2013 CumNUptake NSupplyOrg SumSMN kg N ha OSR Wheat CumNUptake = cumulated N uptake by OSR and wheat NSupplyOrg = cumulated supply of N via organic matter Sum SMN = time course of mineral N in soil profile (0-0.9 m) CumNLeach = Sum of leached NO 3 2 N 180 kg NH 4 -N ha -1 (org) 11

21 Model output: Hohenschulen 2013 CumNUptake NSupplyOrg SumSMN CumNLeach kg N ha OSR Wheat CumNUptake = cumulated N uptake by OSR and wheat NSupplyOrg = cumulated supply of N via organic matter Sum SMN = time course of mineral N in soil profile (0-0.9 m) CumNLeach = Sum of leached NO 3 2 N 180 kg NH 4 -N ha -1 (org) 11

22 12 Scenario analysis 23 simulation periods ( ) 2 sites: HS, Berge 3 treatments: 0 kg N ha -1, 180 kg N ha -1 (CAN), 180 kg NH 4 -N ha -1 (org) Crop management as in 2013 Year specific weather data Net N flow below 90 cm N leaching

23 13 Scenario analysis HS N leaching OSR Wheat 0N 180 CAN 180 org

24 14 Scenario analysis HS & Berge N leaching 0N 180 CAN 180 org 0N 180 CAN 180 org 50.2% / 9.0% / 6.6% of total N input 9.8% / 2.0% / 1.8% of total N input

25 Cum N leaching [kg N ha -1 ] Scenario analysis HS & Berge N leaching Hohenschulen Berge Neue Werte precipitation [mm / 21 months] 15

26 Indirect N 2 O emission [kgn/ha] Indirect N 2 O emission [kgn/ha] 15 Scenario analysis HS & Berge N leaching N 180 CAN 180 org 0N 180 CAN 180 org 50.2% / 9.0% / 6.6% of total N input 9.8% / 2.0% / 1.8% of total N input

27 16 Outline Introduction Indirect N 2 O emissions from NO 3 leaching Indirect N 2 O emissions from NH 3 volatilization Total specific GHG emissions from OSR cultivation Conclusion & Outlook

28 NH 3 volatilization Main source: organic fertilizers 2 major N components: N bound in organic fraction Ammoniacal N (NH 4+ ) N loss via Ammonia volatilization Indirect N 2 O emission Influencing factors: Fertilizer properties Weather after application Application technique 17

29 18 NH 3 volatilization: Measurement Dräger-tube-method Measuring NH 3 concentration of defined air volume flowing through the chambers Calculation of NH 3 fluxes depending on actual weather data

30 NH 3 volatilization [kg N ha -1 ] Indirect N 2 O emission [kg N ha -1 ] 19 NH 3 volatilization HS Berge n/a Approx. 43 kg NH3-N-loss (relative loss: 13% total N)

31 20 N 2 O: relation of indirect emission to direct emission Organic treatment at Hohenschulen % 2013 direct N2O indirect N2O volat indirect N2O leach % % % % % N 2 O-loss 1.27 [kg N ha -1 ] Dec 2012 Mar 2014 (16 months) N 2 O-loss 1.72 [kg N ha -1 ] Sep 2013 Dec 2014 (16 months)

32 Specific GHG-emission [gco 2 -eq./mj] 21 Calculated GHG emissions for cultivation (IPCC) Hohenschulen, experimental period 2013 IPCC study IPCC study IPCC study 0 kg N 180 kg N (CAN) 180 kg NH4-N (org) direct N2O indirect N2O volat indirect N2O leach fertilizer production remaining emission

33 Specific GHG-emission [gco 2 -eq./mj] 21 Calculated GHG emissions for cultivation (IPCC) Hohenschulen, experimental period 2013 IPCC study IPCC study IPCC study 0 kg N 180 kg N (CAN) 180 kg NH4-N (org) direct N2O indirect N2O volat indirect N2O leach fertilizer production remaining emission

34 Specific GHG-emission [gco 2 -eq./mj] 21 Calculated GHG emissions for cultivation (IPCC) Hohenschulen, experimental period 2013 IPCC study IPCC study IPCC study 0 kg N 180 kg N (CAN) 180 kg NH4-N (org) direct N2O indirect N2O volat indirect N2O leach fertilizer production remaining emission

35 22 Conclusion N leaching depended on precipitation (year & site) Slightly higher in unfertilized treatment (lower N immobilization) For most years less than 30% of total N Input (for fertilized treatments) Ammonia emission 13% total N Indirect emissions one quarter to half of total N 2 O emissions NH 3 volatilization > NO 3 leaching

36 23 Outlook Project is ongoing until July 2016 Further sites and years will be analyzed Simulation model for NH 3 emissions under development Transfer of model to estimate indirect N 2 O emissions from different sites and cropping systems

37 Thank you for your attention! This work was funded by FNR (Agency of renewable resources) and UFOP (Union zur Förderung von Oel- und Proteinpflanzen). 37