4 PER SOILS FOR FOOD SECURITY AND CLIMATE INTERNATIONAL RESEARCH PROGRAM

Transcription

1 4 PER SOILS FOR FOOD SECURITY AND CLIMATE INTERNATIONAL RESEARCH PROGRAM Philippe MAUGUIN On behalf of the Science Leadership Team: Jean-François Soussana 1, Jean-Luc Chotte 2, Hervé Saint-Macary 3, Emmanuel Torquebiau 3, Lini Wollenberg 4, Debbie Bossio 4, Rattan Lal 5 1. INRA, 2. CIRAD, 3. IRD, 4. CGIAR, 5. Ohio State University. Scientific Officer: Suzanne Lutfalla

2 Why soil carbon? Outline The 4 per 1000 aspirational target Implications for soils and for crop management Agricultural practices and their potential Linking research and action to create solutions

3 Why soil carbon? Outline The 4 per 1000 aspirational target Implications for soils and for crop management Agricultural practices and their potential Linking research and action to create solutions

4 Without soil carbon sequestration, staying withing 2 C cannot be achieved by the agriculture sector by 2030 N 2 O and CH 4 mitigation (Wollenberg et al., 2016, GCB)

5 Soils contain two to three times more carbon than the atmosphere (Harmonized World Soil Map, UNEP, FAO, JRC 2010)

6 Even under 2 warming, land degradation lowers corn yields by end of century Losses in soil fertility in countries with low or negative nutrient surplus HIGH YIELDS LOW YIELDS (Global EPIC model, dynamic soil, RCP 2.6)

7 Why Soil Carbon? Co-benefits for adaptation, land degradation neutrality and food security 1.4 billion metric tons carbon could be stored annually in agricultural soils, equivalent to a storage rate of 0.48%/year in top soil [after IPCC, 2007, 2014]. 4 per 1000 (0.4%) a global (and local) aspiration Mostly cost competitive at 100 US$ per ton CO 2 Half of the agricultural soils are estimated to be degraded [FAO, 2006] The annual cost of fertilizer to replace nutrients lost to erosion is US $ 110 US $ 200 billion (ITPS, 2016) million metric tons additional grains per ton C stored in soils OM in developing countries [Lal, 2006] Reduced yield variability after soil restoration leading to increased soil organic matter [Pan et al., 2009]

8 Why soil carbon? Outline The 4 per 1000 aspirational target Implications for soils and for crop management Agricultural practices and their potential Linking research and action to create solutions

9 The global carbon cycle in the 2030 s based on Paris Agreement NDCs (assuming no changes in biosphere carbon sinks) Why 4/1000? Gt C (billion metric tons of carbon)

10 Combining global aspirations for soils (4/1000) and for tropical forests: potential for atmospheric CO 2 stabilization Measures: - halting deforestation & forest degradation, - reforestation & agroforestry, - Agricultural soil management - Desertified & salinized soil restoration Total soil carbon sequestration at 3.4 Gt C/yr, i.e. 0.4% of top soil C stock (860 GtC) Gt C (billion metric tons of carbon)

11 Limits of soil carbon sequestration SOC will increase only over a finite period (30-50 yrs locally), up to the point when a new SOC equilibrium is approached, The additional SOC stock will need to be monitored and improved practices will need to be maintained over several decades, Soil phosphorus (P) and nitrogen (N) should be available (root symbioses could help), Soil and water management need to be combined, especially in dry regions.

12 Why soil carbon? Outline The 4 per 1000 aspirational target Implications for soils and for crop management Agricultural practices and their potential Linking research and action to create solutions

13 (Global means, tc/ha) Marrakech 17th November - 1st FORUM of PARTNERS Mean crop carbon cycle change during 30 yrs under 4 per (Photosynthesis) 13.9 (Photosynthesis) (Grazed, burned) (Respiration) 1.5 (Harvest) (Grazed, burned) (Respiration) 2.0 (Harvest) 5.8 (NPP) 7.6 (NPP) 3.4 (residues, manures) 4.5 (residues, manures) Current 2050 (30 yrs of 4 per 1000)

14 Increase in soil organic carbon stock of croplands after 30 yrs under 4 per 1000 compared to current baseline Global annual carbon soil carbon sequestration : 0.3 Gt C/ yr

15 Additional organic carbon returns to soils with 4 per 1000 compared to current baseline Median: tc /ha/ yr, that is +2 tdm (RothC model, inverse mode, bias correction. IIASA, INRA)

16 Why soil carbon? Outline The 4 per 1000 aspirational target Implications for soils and for crop management Agricultural practices and their potential Linking research and action to create solutions

17 Agricultural practices for soil carbon storage Integrated soil fertility management Rangeland Management Conservation tillage Water management Agroecology Agroforestry Organic fertilizers

18 How far can we go and where? Between 0.90 and 1.85 PgC/yr based on % increase in soil carbon Zomer, Bossio et al TNC CIAT in prep

19 Permanence of improved practices is key to achieving soil C sequestration potential Permanent

20 Why soil carbon? Outline The 4 per 1000 aspirational target Implications for soils and for crop management Agricultural practices and their potential Linking research and action to create solutions

21 An integrated research and implementation platform (Paustian et al., 2016, Nature)

22 Thank you for your attention!