Nitrogen input to croplands and its environmental impacts in China

Transcription

1 7th Interntionl Nitrogen Inititive Conference (INI216) Dec. 4-8, 216 Melbourne Nitrogen input to croplnds nd its environmentl impcts in Chin Xioyun Yn Institute of Soil Science Chinese Acdemy of Sciences Xuejun Liu College of Res. & Env. Sci. Chin Agriculturl University

2 Outlines Sptil nd temporl chnges in N input nd NUE Efforts in improving NUE Environmentl impcts Biodiversity loss Soil cidifiction Greenhouse gs blnce Eutrophiction Air pollution

3 Outlines Sptil nd temporl chnges in N input nd NUE Efforts in improving NUE Environmentl impcts Biodiversity loss Soil cidifiction Greenhouse gs blnce Eutrophiction Air pollution

4 Nitrogen input to croplnds

5 Sptil nd temporl vrition of N input to croplnds

6 Nitrogen use efficiency (NUE) Gseous loss N2, NH3, N2O, NOx Synthetic N Orgnic N Bio. N fixtion Soil nitrogen Crop N uptke N input Deposition Leching nd runoff =NUE

7 SOC nd soil N content chnges Ntionl soil survey Soil smpling cmpign C:+8.8% N:+5.1%

8 Chnge in NUE with time 6 5 NUE, %

9 Environmentl Kuznets Curve Zhng et l., 215, Nture 528, 51 59

10 Chnges in NUE with economy growth 6 NUE (N uptke/n input), % Purchsing power prity, USD/cpit/yr 14

11 Heilongjing nd Inner Mongoli 9 Consistent high NUE Loss of soil nitrogen 8 Heilongjing 7 Green: decrese NUE, % Inner Mongoli Red: increse Courtesy of Hung Yo Purchsing power prity USD/cpit/yr

12 Shnghi nd Beijing Urbn re, economiclly developed, consistent low NUE 8 7 NUE, % Purchsing power prity, USD/cpit/yr 3

13 Zhejing nd Gungdong Economiclly developed Soil N little chnge Low NUE Not incresing yet 6 5 Green: decrese NUE, % Red: increse Courtesy of Hung Yo Purchsing power prity USD/cpit/yr

14 Yunnn nd Guizhou Green: decrese NUE, % Economiclly undeveloped Slight decrese in soil N Low nd stble NUE Red: increse Courtesy of Hung Yo Purchsing power prity USD/cpit/yr

15 Mjor griculturl region High or middle level economy Mjor griculturl provinces Lrgely incresed soil N Incresing NUE 6 NUE, % Green: decrese 7 5 Hunn 4 Hebei 3 Shndong Jingsu 2 1 Red: increse Courtesy of Hung Yo 1 2 Purchsing power prity USD/cpit/yr

16 Outlines Sptil nd temporl chnges in N input nd NUE Efforts in improving NUE Environmentl impcts Biodiversity loss Soil cidifiction Greenhouse gs blnce Eutrophiction Air pollution

17 Knowledge-bsed N prctices Enhnced efficiency N fertilizers Controlled relese N fertilizer Nitrifiction inhibitor Urese inhibitor Optimized N ppliction Reducing bsl fertilizer N rtio Incresing N splitting frequency Deep plcement of fertilizer Fertilizer recommendtion bsed on soil test

18 Fertiliztion bsed on soil test progrm An ccumultive re of 1 million hector by 215

19 Fertilizer recommendtion systems Computer ccess Touching pnel Plm ccess

20 Effects on productivity nd N loss (59) (11) (72) -5.6% (116) (36) (43) (37) NUE +48.2% N2O emission NH3 emission (232) (b) -3.7% (44) (17) (14) (13) -31.2% (57) (12) (2) (25) -35.3% N leching +1.3% Loss indexes (42) (15) (12) (15) (123) (41) (52) -27.6% N runoff () Totl N uptke Grin yield Productivity indexes (3) -6-2 Overll Effects of N prctice (%) Rice Whet Effects of N prctice (%) Overll Rice Whet Corn Achieved on n verge N reduction of 28% -1 Corn (27) (16) (6) (5)

21 Brriers Effects of these N prctices vried mong different crop species nd soil properties. Mny frms re still smll scle, frmers knowledge, environmentl wreness still need to improve Opportunity cost (time, lbor, trining/eduction costs) for implementing Lck of mechniztion Ntionl geogrphy, 211

22 Outlines Chnges in nitrogen input nd NUE Efforts in improving NUE Environmentl impcts Biodiversity loss Soil cidifiction Eutrophiction Air pollution

23 (Gllowy et l., 23)

24 Significnt increse in lef N in nturl vegettion () nd N uptke in long-term unfertilized croplnds (b) during 198s nd 2s. 8 Woody (n=36) 7 Folir N (mg g-1) 6 (n=538) (n=232) *** *** (n=244) All Herbceous *** (n=319) 5 (n=75) W_198s 2 18 b Rice (n=47) 14 H_2s A_198s A_2s Mize * (n=45) 12 1 H_198s Whet * 16 N uptke (kg N h-1) W_2s (n=53) * (n=47) (n=43) (n=43) Folir N concentrtion 198s: mg/g 2s: mg/g Increse: 5.9 mg/g (+3%) Crop N from zero-n plots 198s: 71.1 kg N h-1 2s: 82.4 kg N h-1 Increse: 11.3 kg N h-1 (+15%) These results suggest N enrichment in Chin s terrestril ecosystems since *, *** denote significnt difference t.5,.1 level R_198s R_2s W_198s W_2s M_198s M_2s (Liu et l., 213. Nture, 494: )

25 Outlines Chnges in nitrogen input nd NUE Efforts in improving NUE Environmentl impcts Biodiversity loss Soil cidifiction Eutrophiction Air pollution

26 Impct of N ddition on grsslnd plnt community Species Richness Aboveground Biomss (g m-2) 45 1 Evenness (E) 2. Diversity (H) ShnnonWiener Index N Input Rte (kg N h yr ) Pielou Index Evenness N Input Rte (kg N h-1 yr-1) (Song et l, 212. J. Arid Lnd)

27 Elevted N deposition (e.g. 3 kg N h -1) led to significnt decline in forb species richness in temperte grsslnd (Duolun, IM) Reltionship between N ddition rte nd species richness Species Richness 4 c b bc b b b b b b b b 3 Grsses b b b b b b b b b bc b c d d cd Forbs dc bc 3 6 d N Input Rte (g N m-2 yr-1) Cesstion of N ddition (Song et l, 211, Biogeosciences)

28 Biodiversity loss nd recovery under vrious N ddition conditions 6 First five-yer results Second five-yer results Species Richness b Cesstion of N48 ddition since 29 Reltionship between N ddition rte nd species richness for grsses () nd forbs (b) from 25 to 215. (Ho et l., 216. unpublished)

29 Outlines Chnges in nitrogen input nd NUE Efforts in improving NUE Environmentl impcts Biodiversity loss Soil cidifiction Eutrophiction Air pollution

30 Averge ph decline ws.5 units during 198s nd 2s Soil ph decline: Csh crop systems > Cerel crop systems (Guo, Liu, Zhng, et l., 21. Science 327: 18-11)

31 -1-1 H production flux (kmol h yr ) H+ production budget of min fctors in four typicl Chinese cropping systems. W-M: Whet mize; R-W: Rice-whet; R-R: Rice-rice; G-V: Greenhouse vegetbles. 26 N cycling S uptke P uptke BCs uptke Net H production W -M R-W R-R G-V Cropping system 216/12/19 (Guo, Liu, Zhng et l., 21. Science, 327: 18-11) 31

32 Chnges of soil ph fter 12-yer fertiliztion in whet-mize cropping system (Annul N input 3 kg N/h, Initil ph 5.7 in 199) M ph 6.2 NPKS ph 4.6 NPKM ph 6.1 ph 4.5 NPK PK ph 5.3 NK ph 4.3 NP N Control ph 4.5 ph4.2 ph5.5 (Xu MG 21)

33 Men ph decrese:.63 units (Yng et l., 212. GCB)

34 Continuous N ddition led to significnt soil cidifiction nd chnges in microorgnism communities 8. ph(-1cm) ph(1-2cm) ph vlue 7. (Duolun, Inner Mongoli, Chin) N N6 Topsoil (-1 cm) N12 N24 Subsoil (1-2 cm) (Zeng et l., 216. SBB)

35 12 Soil ph decrese:.36 units! ph vlue Atmospheric deposition contributes to 84% of H+ production in forest soils s Number of dt s (Zhu et l AE)

36 Outlines Chnges in nitrogen input nd NUE Efforts in improving NUE Environmentl impcts Biodiversity loss Soil cidifiction Eutrophiction Air pollution

37 Chin s eutrophied lke re hs incresed from 135 (197) to 87 km2 (27). 87 Are (km2) s 197s s (Science 29, ) s 2s (the Stte Ocenic Administrtion, Annul Number of Red Tides 9 27 (Jin, 29)

38 N deposition onto costl ses of Chin Totl N deposition to Bohi Se: 22 kg N h-1 yr-1 Annul N deposition in costl zone: 34 kg N h-1 * * * * * * 38 Assuming hlf of costl N deposition rte ( 17 kg N/h) onto Bohi, Yellow, Est Chin nd South Chin Ses (3 16 km2), totl N deposition mounts to 5 Tg N yr-1 to the 4 mrine ecosystems surrounding Chin. 216/12/19 (Zhng et l., 213; Luo et l., 214)

39 Outlines Chnges in nitrogen input nd NUE Efforts in improving NUE Environmentl impcts Biodiversity loss Soil cidifiction Eutrophiction Air pollution

40 Beijing Smog 214 CAU west cmpus, Feb. 26th, µg/m3 77 µg/m3

41 198s: 13.2 kg N h-1 2s: 21.1 kg N h-1 Increse: 8 kg N h-1 or 6% B u lk N d ep o sitio n (k g N h -1 ) 7 6 y=.411x (r2=.7; n=671; p<.1) B u lk N co n cen trtio n (m g N L -1 ) 16 1b c y=.63x (r2=.12; n=866; p<.1) N H 4 -N /N O 3 -N in p recip ittio n 25 (Liu nd Zhng et l., 213. Nture 294: ) 2 y= -.144x (r2=.176; n=89; p<.1)

42 Nture Chemicl composition nd source pportionment of PM2.5 during the high pollution events of 5 25 Jnury 213 in Beijing, Shnghi, Gungzhou nd Xi An cities Sum of pnh4+ + pno3- contributed to 23% of PM2.5 (158 µg/m3) in Beijing during Jn (Hung et l., 214. Nture)

43 A successful exmple t Urumqi: Shift of col to nturl gs for heting N dry deposition decresed from 26 kg N h-1 (212) to 16 kg N h-1 (215). Gs heting re Cogenertion heting re Nturl gs consumption (million cubic meters) Col heting re 15 2 Heting re (km ) Heting period (Song et l., 215. EST 49: ) Heting period Heting period

44 Conclusions nd outlook Overll N input/output rtio is 43% currently, with n slight incresing trend in recent yers; Huge regionl differences in the trend exist due to vrious griculturl structure nd soil conditions; Enhnced N cycling hs impcted lrgely to both griculturl nd nturl ecosystems, including biodiversity loss, soil cidifiction, eutrophiction, ir pollution, etc.; Knowledge bsed prctices in improving N use re promising, lthough brriers still exist.

45 4 65 N fertilizer consumption STNR progrm initited PFP Turning point of PFP 4 15 Gr in pr oduction (Million ton) N fer tilizer consumption (Tg yr -1) PFP (kg gr in kg-1 N) 6 Grin production 35 Chin is now t historic turning point to increse NUE nd crop production menwhile reducing its N environmentl impct Yer (Liu et l., 216. EST)

46 Thnks for your ttention!

47 7 35 Vegetble 3 蔬菜产量 5 水果产量 25 Grin 谷物产量 4 氮肥总量 Fruit N fertilizer N consumption 14 ton N Crop production 14 ton 6

48 Implementtion County Level Arble Lnd Resource Mngement Informtion System Developed by Yngzhou Soil nd Fertilizer Sttion

49 Overll effects of N prctices (+) Incresed N leching 16 45% ( ) 14 37% ( ) (Rice, Whet, Corn) ( ) Decresed 6 21% (+) vs. 3% ( ) Optiml N rte N removl 5 12% (+) Optiml N rte 6% ( ) Grin 1 1% (+) N runoff Hydrosphere NEB 3 13% (+) Humn Input cost 5 4% ( ) Croplnd Fertilizer N + N prctices NI 28%(+) Industry 31 62%( ) Atmosphere N 2O NH3

50 Nitrogen input to croplnds