1. Trends of phosphorus use efficiency in the food chain of China Lin Ma 1, Zhaohai Bai 2, Wenqi Ma 3, Gerard Velthof 4, Oene Oenema 4, Fusuo Zhang 2 1 The Chinese Academy of Sciences, 2 China Agricultural University, 3 Agricultural University of Hebei, 4 Alterra, Wageningen University and Research Centre. E-mail: malin1979@sjziam.ac.cn 5 th Phosphorus in Soils and Plants Symposium, 29 th September, Montpellier, France

2. Outline 1.Why study phosphorus (P) use efficiency in the food chain of China? 2.Definitions of phosphorus use efficiency (PUE) 3.Changes of PUE in the food chain of China 4.Options of sustainable P use in the food chain

3. Why study PUE in the food chain of China? FAO database Question: Is it a sustainable food system?

4. Atmosphere N 2, NH 3, N 2 O Exports and losses Surface waters Groundwater Erosion and runoff Leaching N Crop production （ soil accumulation ） P Animal production imports Food processing Human consumption NUFER model (NUtrient flows in Food chains, Environment and Resources use) Regional and national scale of China 1950-2010, and 2030 18 main crops 11 animal categories Households in rural and urban (Ma et al., JEQ 2010)

5. Indicators of nutrient use efficiency P cost of food (kg/kg) PUEf - Phosphorus use efficiency in the food chain, % PUEc - Phosphorus use efficiency in crop production, % PUEa - Phosphorus use efficiency in animal production, % (Ma et al., JEQ 2010)

6. P flows in food chain in China Total P input was 5 times larger in 2005 than in 1980; P cost of food production was 4 kg/kg in1980 and 13 kg/kg in 2005. (Ma et al., 2012)

7. PUE in the food chain of Chian Note: PUE= (O Main product / I Total )*100 ， Phosphorus use efficiency. PUEc, PUEa and PUEf are the PUE in crop production, animal production and food chain. (Ma et al., Unpublished data, Smit et al., 2010 and Suh et al., 2011 ) USA and NL PUEc = ~ 60% PUEa = ~ 35% PUEf = ~ 20%

8. P flux increased dramatically in the food chain of China (Ma et al., Unpublished data)

9. P cycling rate decreased in the food chain of China (Ma et al., Unpublished data)

10. P losses in food chain in China Percentage of P losses from sub-systems P losses (10 4 ton) (Ma et al., Unpublished data)

11. Options of sustainable P use in the food chain 1.Improving PUE in crop production 2.Improving PUE in animal production 3.Recycling wastes from the whole chain 4.Lowering human consumption of animal products Ma et al., EST 2013

12. (Chen et al., PNAS, 2011) ----Increase yield and PUE by 30-50% Double High Technology: from technology to farmers’ practices Field school Training

13. Phosphorus use efficiency in dairy production in China Animal: Milking dairy; Herd, including milking dairy, calves and heifers; System, crop-dairy production chain Improving PUE in animal production Bai et al., JEQ 2013 PUE at herd level is 25-35% in EU and USA.

14. P footprint of China’s pig production in 2010 Bai et al., EST 2014 Recycling wastes from the whole chain

15. Lowering human consumption of animal products The Chinese food dietary guidelines (Ma et al., JEQ 2013)

16. P losses from crop production and animal production (Ma L. et al., STOTEN 2012) Regional variations in P management

17. Summary Food P cost increased dramatically in the past several decades in China, following with low PUE and high P losses. Optimizing diets and implementation of integrated nutrient management would decrease P losses, and would greatly increase PUE in the whole food chain. A food chain approach is really needed to improve sustainable P management in the food systems.

18. Some main publications Ma L., Wang F. H., Zhang W. F., Ma, W. Q., Velthof G.L., Qin W., Oenema O., Zhang F.S., Environmental assessment of nutrient management options for the food chain of China. Environmental Science & Technology, 2013, 47 (13), 7260-7268. Ma L., Zhang W. F., Ma W.Q., Velthof G.L., Oenema O., Zhang F.S., An analysis of developments and challenges in nutrient management in China. Journal of Environmental Quality, 2013, 42 (4): 951-961. Bai Z.H., Ma L., Oenema O., Chen Q., Zhang F.S., Nitrogen and phosphorus use efficiencies in dairy production in China. Journal of Environmental Quality, 2013, 42 (4): 990-1001. Hou Y., Ma L., Gao Z. L., Wang F. H., Sims J. T., Ma W. Q., Zhang F. S., Nitrogen and phosphorus flows and losses in the food chain in China, 1980-2010. Journal of Environmental Quality 2013, 42 (4): 962-971. Ma, L. G. L. Velthof, F. H. Wang, Z. Liu, Y. Zhang, J. Wei, J. P. Lesschen, W. Q. Ma, O. Oenema, F. S. Zhang et al.(2012) Nitrogen and phosphorus use efficiencies and losses in the food chain in China at regional scales in 1980 and 2005. Science of the Total Environment 2012, 434: 51-61. W.Q Ma, Ma L., Li J. H. et al., Phosphorus flows and use efficiencies in production and consumption of wheat, rice, and maize in China, Chemosphere, 2011, 84(6): 814-821. F. Wang, J.T. Sims, Ma L., W. Ma, Z. Dou, and F. Zhang, The Phosphorus Footprint of China’s Food Chain: Implications for Food Security, Natural Resource Management, and Environmental Quality, JEQ, 2011, 40(4): 1081-1089. Ma L., W.Q. Ma, G.L. Velthof et al,. Modeling Nutrient Flows in the Food Chain of China, Journal of Environmental Quality, 2010, 39(4): 1279-1289. Bai Z.H., Ma L., Qin W., Oenema O., Chen Q., Zhang F.S., Changes in Pig Production in China and Their Effects on Nitrogen and Phosphorus Use and Losses. Environmental Science & Technology, 2014 (Minor revision)

19. Our food pyramid in the future Thanks for your attention! 5 th Phosphorus in Soils and Plants Symposium, 29 th September, Montpellier, France