Nutrient management in the food chain of China

Nutrient management in the food chain of China Fusuo Zhang Lin Ma China Agricultural University Feb. 25 , 2014, Beijing, China-UK Workshop on Nutrient Management and Water Resource Protection

Outline Ø Problems and challenges Ø Nutrient flow in the food chain Ø Strategies of nutrient management

Food security issue of China is always a global concern Lester Brown 1994 2008 2011 • Who will Feed China? • Will China Starve the World? • Can the United States Feed China?

Population (M) Grain demand production (M ton) It took several hundred years to realize the dream of food sufficiency in China Year (Data from the Statistic Bureau of China; Demand was estimated by using average grain demand of 400 kg/capita/yr)

Grain production and resources input Grain yield in China has been merely secured by much higher input of resources including fertilizer, irrigation, plastic film and pesticides. (National bureau of statistics of China, 1961 -2010; Zhang et al. , 2011)

130 500 China 110 GHGI(kg CO 2 eq Mg-1) Relative yield(%) Yield response curve 300 90 70 Developed countries 200 Africa Environment impact by N loss 50 100 0 30 0 50 100 150 200 250 300 350 N rate (kg N ha-1)

Fertilizer Overuse and Misuse

NATURE (Liu et al. , 2013) Air pollution Bulk N deposition has increased from 13 kg N ha-1 in 1980 s to 21 kg N ha-1 in 2000 s, among which agricultural Nr sources occupied ~2/3.

Soil acidification Soil p. H was decreased by 0. 5 units due to overuse of N fertilizers. -0. 5

Eutrophication China’s eutrophied lake area reached 8700 km 2 (2007) over the last 4 decades. 10000 8700 79 75 60 45 30 20 15 0. 2 0. 5 1960 s 8000 Area (km 2) Annual Number of Red Tides 90 1970 s 4 0 6000 5000 1980 s (Science 2009, 1014 -1015) 135 600 0 1970 s 1980 s 2000 s (China State Oceanic Administration, 2009） 4000 2000 1990 s 2007 (Jin, 2009)

Outline Food security and fertilizer application Ø Nutrient flow in the food chain Strategies of nutrient management

Nutrient management in the food chain Ma Lin’s thesis

(Zhang et al. , 2012)

Ø N fertilizer input is 1. 7 fold of crop uptake Ø Total N input is 2. 4 fold of crop uptake 2. 4 fold 1. 7 fold N input and crop uptake in Chinese crop land in 1961 -2009 （张卫峰等，2013 ） Calculated by using NUFE model (Ma et al. , 2010) and FAO data base www. fao. org

“Better Life” in China - rapid growth of animal food, fruits and vegetables 1961 1989 2010 The percentage of plant protein and animal protein (Ma et al. , 2013, Data source: FAO)

Poultry numbers Pig, meat cow, sheep and goat, milk cow numbers Booming development of animal husbandry in China in the past 30 years Year (the Statistic Bureau of China)

Des-coupling of crop and animal production ( Wang et al. , 2010)

Quantify nutrient flow in the food chain by a new model NUFER (NUtrient flows in Food chains, Environment and Resources use) Atmosphere N 2, NH 3, N 2 O Food security Environmental Human consumption Sustainability Exports and losses Food processing imports Resource use efficiency Animal production Crop production （soil accumulation） Erosion and runoff N Leaching Groundwater P Surface waters (Ma et al. , 2010)

High N fluxes in the food chain of China (Hou et al. , 2013) 1980 1990 Air 8. 6 House 3. 1 Hold 2. 8 0. 5 0. 8 0. 14 Animal Production 7. 4 2. 0 Crop Production 21 17. 3 House. Hold 3. 5 + 0. 7 2. 3 + 3. 6 + 11. 5 Water 3. 3 + 2. 8 Air 24. 1 +1. 7 House. Hold 4. 1 + 0. 6 House. Hold 5. 0 + 0. 9 3. 3 0. 9 Animal Production 11. 0 Crop Production 28. 9 2010 Air 22. 4 + 8. 1 2. 8 0. 17 3. 8 1. 1 2000 Air 14. 3 + 5. 7 Unit: Million tonne (Mt) + 8. 1 1. 5 0. 18 Animal Production 18. 1 5. 5 1. 3 Crop Production 40. 5 + 11. 6 Water 6. 1 3. 5 + 5. 6 + 3. 1 0. 15 Animal Production 21. 0 7. 5 1. 3 Crop Production 46. 1 + 5. 6 Water 11. 7 1. 1 +3. 5 Water 15. 2

Amounts of N losses(Mt) Total N losses to environment from 1980 to 2010 45 40 35 30 25 20 15 10 5 0 ～ 4 times N losses to water N losses to air 11. 7 15. 2 6. 1 3. 3 8. 6 1980 14. 3 1990 22. 4 24. 1 2000 2010

Contribution of N losses from different systems To water bodies To atmosphere food consumption animal production crop production 80% Percentage (%) 100% 60% 40% 5. 9% 15. 0% 33. 9% 60% 43. 3% 40% 20% 0% 0% 1980 1990 2000 Year 2009

High P fluxes in the food chain of China Unit: Million tonne (Mt) 1980 1990 House 3. 1 Hold 0. 37 0. 04 0. 06 Animal Production 1. 1 0. 4 Crop Production 21 2. 3 House. Hold 0. 46 + 0. 09 0. 33 0. 02 + 1. 0 2000 + 2. 1 Water 0. 36 0. 08 Animal Production 2. 1 0. 9 0. 14 Crop Production 4. 4 + 0. 37 House. Hold 0. 54 + 0. 08 0. 40 0. 02 + 1. 9 Water 0. 73 0. 13 0. 02 Animal Production 4. 0 1. 2 Crop Production 6. 9 +1. 25 House. Hold 0. 62 + 0. 08 0. 46 0. 02 0. 17 + 2. 5 2010 + 0. 5 0. 47 Animal Production 4. 5 0. 18 1. 6 Crop Production 8. 3 + 1. 4 Water 1. 98 0. 15 +0. 85 Water 2. 83

Total P losses to environment from 1980 to 2010 ～ 8 times Amounts of P losses(Mt) 3 P losses to water 2. 5 2 1. 5 2. 83 1 1. 98 0. 5 0 0. 36 0. 7300000001 1980 1990 2000 2010

Contribution of P losses from different systems To water bodies

N and P losses of China in 2005 and EU in 2000 (kg N ha-1) NH 3 N 2 O N 2 NOx N losses via leaching, runoff and erosion P losses via leaching, runoff and erosion (Velthof et al. , 2009; Ma et al. , 2010) * No data China EU in 2005 in 2000 118 17 4 2 68 44 15 2 137 16 22 *

NUE and PUE in China in 2005 26 16 9 Global NUEc NUEa NUEf China in 1980 32 8 15 PUEc PUEa PUEf 63 13 24 36 17 7 38 ~21 19 ~50 20 -34 14 Note: NUE= (O Main product / I Total)*100 (Smil, 2002; Howarth et al. , 2003; Van der Hoek, 1998; Galloway, 2002; Liu et al. , 2009; Schroder et al. , 2010)

Three-Step Strategy to increase crop yield and nutrient use efficiency at the same time - For ensure both food security and environment quality simultaneously Crop productivity The 3 rd step Yield increase 30%-50% The 2 nd step Yield increase 10%-20% （High-yield） Increase soil fertility （saving fertilizer） The 1 st step At present Saving N by 30% without yield penalty Water and nutrient input

2009 (First step) Cut down N fertilizer by 30 -50% reduces N loss into environment greatly without diminishing crop yield!

----Increase yield and NUE by 30 -50% (Third step) Mean maize grain yield and modeled yield potential, N balance (fertilizer inputs-harvest outputs) and N applied per unit of grain produced for different management systems: integrated crop and soil system management approach (ISSM, n=66), farmers’ practice (FP, n=4548), and high-input, high-yielding studies (HY, n=43). (Chen et al. , PNAS, 2011)

Three-Step Strategy to increase animal productivity and decrease nutrient losses at the same time

Nutrient management in food chain 2 Three-Step Strategy in crop production Decrease demand 1 Optimize diets Decrease pressure Fertilizer industry 3 Recycle wastes Decrease losses 2 Three-Step Strategy in animal production Environment

N and P cost in the food chain in China (Ma et al. , 2014)

Thanks for your attention ! Acknowledgments NSFC, Mo. A , Mo. E, MOST