NITROGEN FERTILIZER USE AND GRAIN PRODUCTION IN CHINA

Transcription

1 NITROGEN FERTILIZER USE AND GRAIN PRODUCTION IN CHINA Shutian LI, Jiyun JIN IPNI China Program Dec. 5, 010, New Delhi

2 Fertilizer N consumption

3 Fertilizer N consumption from 1953 to N consumption, 10000t Source: China Agriculture Year Book

4 Relationship between N consumption and grain yield Grain Yield, kg/ha y = x x R² = ** N consumption, Mt Based on China Agriculture Year Book Total grain output, Mt y = x x R² = 0.973** N consumption, Mt

5 Chemical fertilizer consumption and distribution in China 16 kg N/ha crop area 10 kg N/ha crop area 11 kg N/ha crop area 147 kg N/ha crop area 04 kg N/ha crop area 5 kg N/ha crop area Source: China Agriculture Year Book

6 Area of cash crop increased rapidly since 1978 Area of cash crops including cotton, sugar crops, oil crops vegetables and fruits increased rapidly since Before 1978, the percentage of cash crops was 5-8% of total crop area, but increased to more than 30% now. Changes of cash crop area since 1950 Planting area of cash crops, Mha

7 Changes of planting area of grain crops in China Grain area, Mha

8 Fertilizer N rate in grain crops According to the changes of crop area, assuming fertilizer used in grain crops was 90% before1978, 80% from 1979 to 1989, 70% from 1990 to 1999, 60% since 000. The mean calculated N applied in grain crops increased and in 009 the rate was 158kg/ha of crop area. N rate in grain crops, kg/ha Source: China Agriculture Year Book

9 N use efficiency in grain crops

10 Changes of partial factor productivity of fertilizer N since 1950 Total grain production, Mt Grain production Grain yield Grain yield, kg/ha PFP N, kg grain/kg N PFP N, kg grain/kg N PFP N, kg grain/kg N Based on China Agriculture Year Book

11 The relationship between average cereal yields and average fertilizer-n use 6000 Grain yield, kg/ha N rate increased by 50%, PFP decreased 6 kg/kg N rate doubled, PFP decreased 16 kg/kg Before Fertilizer N rate, kg/ha planting area Based on China Agriculture Year Book

12 Levels of cereal production, N fertilizer use on cereals, and cereal N use efficiency by world regions Country Cereal yield, t/ha N rate, kg/ha PFP N, kg/kg 1 China North Am NE Asia W Europe E Europe, C Asia Ocean Africa W Asia NE Africa South Asia SE Asia East Asia Latin Am World Data of China was caculated based on China Agriculture Year Book. Dobermann, 006 ( invited paper)

13 Changes of agronomic efficiency of N (AE N ) in main grain crops in China Crops N rate kg/ha AE N kg grain/kg N rate kg/ha AE N kg grain/kg N rate kg/ha AE N kg grain/kg Rice Wheat Maize Lin and Li, 1989 IPNI China program unpublished data

14 Changes of yield response to N fertilizer (kg/ha) Crops Rice Wheat Maize Lin and Li, 1989 IPNI China program unpublished data

15 N recovery efficiency in main grain crops (00-007) Crops Trial No. Response kg/ha AE N kg grain/kg N RE N % Rice Wheat Maize Sources: IPNI China program unpublished data

16 N use efficiency in different regions: AE=11-4kg/kgN, RE= Dobermann, 007

17 1. Agronomic efficiency (AE) of grain crops in China is about 10kg grain/kg N. Agronomic efficiency of N (AE-N) in China is about half of the world average; 3. Crop recovery efficiency (RE) of the first crop in China is about 15-0 lower than world average; 4. The low N efficiency in China is due to high N rate for high yield production, and improper use of fertilizers; 5. It is important to further improve fertilizer use efficiency in China for sustained increase of crop production; 6. With the highly intensified cropping systems in China, further improvement of fertilizer use efficiency is a big challenge, but can be done with advances in fertilization related science and technology. 010/1/8

18 Strategy to improve N use efficiency in China

19 Technology development to improve nutrient use efficiency Soil testing and fertilizer recommendation Use of organic resources Best management practices (BMPs) Slow/controlled release fertilizers Fertigation

20 Develop different nutrient application strategies based on soil fertility If N deficient or in low organic matter, then fertilization to increase yield and build up soil fertility If adequate, then fertilization to maintain soil fertility If over fertilized and accumulated nitrate in soil profile, reduced fertilizer N and deplete nutrients in soil. Fertile, productive, healthy crop land will be developed.

21 Made full use of organic sources of N Estimated organic fertilizer sources in China Sources Amount (Mt) N (Mt) Animal waste Straw Cake manure Green manure Total (Li et al., unpublished)

22 4R Nutrient Stewardship Biodiversity Resource use efficiencies: Energy, Labor, Nutrient, Water Soil erosion CROPPING SYSTEM OBJECTIVES Healthy environment Nutrient loss Water & air quality Adoption Nutrient balance Yield Net profit Productivity Durability Soil productivity Ecosystems services Farm income Profitability Return on investment Quality Yield stability Working conditions

23 Thanks and welcome comments