Chronological Changes of Soil Carbon Stock in Korea

Transcription

1 Chronological Changes of Soil Carbon Stock in Korea Yoo-Hak Kim, Seong-Soo Kang, Myung-Sook Kim Soil & Fertilizer Management Division, Department of Agricultural Environment, National Academy of Agricultural Science (NAAS)

2 1. Introduction

3 Soil Organic Carbon (SOC) Soil organic carbon (SOC) is composed of a plant debris and decomposition intermediates and microorganism. i The C occurs in four pools: Atmosphere, Terrestrial biota, Soil, and Ocean. 7 Pg C in atmosphere, about 5 Pg C in terrestrial biota, about 1,5 to, Pg C in soil, 39, Pg C in the oceans.

4 Carbon Cycle among Pools The amount in soils is at least times that in the atmosphere.

5 Carbon Cycle among Pools Climate change occurs by CO increase of atmosphere. If CO of ocean is equilibrated with atmosphere, To mitigate CO increase of atmosphere, we must reduce CO from fuel or increase C sequestration of soils. Can the soils accumulate more carbon? If yes, how much C can be sequestered in soil? To know C sequestration of soil, we must know SOC stock and C sequestration potential.

6 C Sequestration Potential of Soil C sequestration potential is different from soil site characteristics altitude and vegetation management practices Paddy soil, upland soil soil properties p parent material and soil texture, etc Monitoring SOC of the soils is prerequisite.

7 Database of C Stock in Korea Korea has established fertilizer recommending system since 19. SOC is an indicator for recommending N fertilizer. The C of the soils is determined by total organic C. Korea has performed projects on soil testing. More than 15 county laboratories have taken part in. The 5 projects 19~199: Ten years project on integrated soil improvement for paddy soils 1995~1999: Five years project on integrated soil improvement for upland soils ~: Soil testing on the fields of cultivating strategic crop 5~: Soil testing on the fields for major crop 9~ : Soil testing for farm land The data of soil testing has been input in agricultural soil information system It can be input multiplicate to recommend fertilizers for several crops.

8 Objects Introduce SOC Stock in Korea Chronological changes of SOC at different Crops Management practices Soil properties Find major indicators for C stock Relationship between SOC changes and soil factors Etblihth Establish the possible C sequestration ti By comparing SOC stock and C sequestration potential C sequestration potential according to soil properties C sequestration potential according to soil properties By adapting the management practices on C sequestration

9 . Chronological changes of SOC in Korea

10 Chronological changes of SOC Table 1. Chronological l changes for Korean arable soils Soils Paddy soils Upland soils Project period SOC (g C kg Sample sites ) Standard (Number) Mean deviation 19~19, ~ 393, ~ 93, , ~ , ~ 13, ~ 399,.5. 9,

11 What is the driving force for SOC change?

12 Chronological changes in paddy rice (gc kg -1 ) SOC 19~19 ~ 5~ 9 Rice Fig. 1. Chronological changes of SOC of paddy rice.

13 Distribution of SOC in paddy soils 5 Count Total 19~ ~1999 ~ 5~ 9 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 15 15~ ~ 5 5~ 3 3~ 35 35~ ~ 5 5~ ~1 ~ * SOM = 1.7*SOC SOM (g kg -1 ) *

14 Chronological changes in upland crops SOC (gc kg-1 1) ~1999 ~ 5~ 9 Red pepper Soy bean Chinese cabbage Ginger Corn Fig.. Chronological changes of SOC of upland soils cropping major crops.

15 Distribution of SOC in upland soils Count 15 5 Total 1995~1999 ~ 5~ 9 ~1 ~3 ~5 7.5~ ~ 15~ ~ 5~ ~3 35~ ~ 5~ ~5 55~ ~ 5~ ~7 ~ ~9 ~ 15 ~ 3 SOM (g kg -1 )

16 Could SOC be changed by management practices? Chronological changes of SOC Sustained constant level in paddy soils: 13 g C kg -1 Changed by year or by different crops: ~17 g C kg -1 SOC was changed by land use SOC of upland soils All arable upland soils in the later 199s:. g C kg -1 Beneficial crops in the s: 15.~.9 g C kg -1 SOC was changed by applying compost Management practices are the driving force for SOC change

17 3. The Effects of Soil Properties on SOC Stock

18 Is SOC of paddy soils related to soil properties?

19 The effect of topography in paddy soils SOC (gc kg-1) 1 19~19 ~ 5~ 9 Plains Vll Valley M.Footslope Terrace Alluvial fan Valley-alluvial fan Hilly Fig.. Chronological l changes of SOC of paddy soils located in different topography.

20 The effect of parent material in paddy soils SOC (gc kg-1 1) 1 19~19 ~ 5~ 9 Acid rock alluvium River alluvium Marine alluvium Acid rock colluvium Diluviumi Gray shale alluvium Porphry alluvium Fig. 3. Chronological l changes of SOC of paddy soils by parent material.

21 The effect of great group in paddy soils ) (gc kg-1 SOC 1 19~19 ~ 5~ 9 Gray soil Alluvial soil Red-yellow soil Saline soil Alluvial soil/red-yellow soil Fig.. Chronological l changes of SOC of paddy soils by great soil group.

22 Paddy SOC according to site characteristic SOC (gc kg-1) SOC (gc kg-1) ~19 ~ 5~ 9 Plains Valley M.Footslope Terrace Alluvial fan Valley-alluvial fan Hilly Acid cdrock alluvium uvu River alluvium Marine alluvium Acid rock colluvium Diluvium Gray shale alluvium Porphry alluvium SOC is differed from topography, parent material, etc. But SOC pattern showed steadystate because of removal of rice straw 19~19 ~ 5~ 9 SOC (gc kg-1) 1 Gray soil Alluvial soil Red-yellow soil Saline soil Alluvial soil/red-yellow soil 19~19 ~ 5~ 9

23 The effect of drainage in paddy soils SOC (gc kg-1) 1 19~19 ~ 5~ 9 Poorly drainage Imperfectly drainage Moderately well d. Well drainage Fig. 5. Chronological l changes of SOC by drainage condition of paddy soils.

24 The effect of gravel content in paddy soils (gc kg-1 1) SOC 1 19~19 ~ 5~ 9 <% %-35% >35% Fig.. Chronological l changes in SOC according to gravel content t of paddy soils.

25 The effect of soil texture in paddy soils gc kg-1) SOC ( 19~1919 ~ 5~ 9 Fine loamy Coarse loamy Fine silty Clayey Coarse silty Sandy Coarse loamy/sandy Fig. 7. Chronological l changes in SOC according to soil texture t of paddy soils.

26 The effect of effective soil depth in paddy soils SOC (gc kg-1) <.m.m-.5m.5m-1m >1m 19~19 ~ 5~ 9 Fig.. Chronological changes in SOC of paddy soils according to effective soil depth.

27 Paddy SOC according soil properties SOC (gc kg-1) SOC (gc kg-1) ~19 ~ 5~ 9 19~19 ~ 5~ 9 Poorly drainage Imperfectly drainage Moderately well d. Well drainage Fine loamy Coarse loamy SO OC (gc kg-1) Fine silty Clayey Coarse silty SOC (gc kg-1) 19~19 ~ 5~ 9 19~19 ~ 5~ 9 <% %-35% >35% <.m.m-.5m 5m-1m.5m SOC stock is differed from soil properties. Minimum SOC stock, SOC sequestration potential will be different from soil properties. >1m

28 SOC changes by applying compost 5 SO OC (g C kg -1 ) 15 5 NPK NPK+Compost Fig. 9. SOC changes of paddy soil by applying compost 7.5 MT ha -1 annually.

29 Could SOC of paddy soils be affected by soil properties? SOC stock of paddy soil is related to soil properties. Rice straw has been removed to utilize for cattle food. SOC was low in poor drainage and sandy soil and shallow soil depth. Minimum SOC stock of paddy soil SOC sequestration potential of paddy soils Annual application of compost made SOC of paddy soil increase: from 13 to g C kg -1 SOC sequestration potential of paddy soils will be different from soil properties. SOC sequestration potential depends on soil properties. Paddy soil could sequester the air C.

30 Is SOC of upland soils related to soil properties?

31 The effect of topography in upland soils SOC (gc kg-1) 1 Valley-alluvial fan M.Footslope Hilly Plains Vll Valley Alluvial fan Mountains 1995~1999 ~ 5~ 9 Fig.. Chronological changes of SOC of upland soils by topography.

32 The effect of parent material in upland soils SOC (gc kg-1) ~1999 ~ 5~ 9 Acid rock alluvial colluvium Acid rock colluvium Acid rock alluvium River alluvium Fig. 11. Chronological changes of SOC of upland soils by parent material.

33 The effect of great group in upland soils 1 SOC (gc kg-1) Alluvial soil Red-yellow soil Regosols Gray soil Lithosol 1995~1999 ~ 5~ 9 Fig.. Chronological changes of SOC of upland soils by great soil group.

34 Upland SOC according to site characteristic SOC (gc kg-1 ) SOC (gc kg-1 ) SOC (gc kg-1) ~1999 ~ 5~ ~1999 ~ 5~ 9 Valley-alluvial fan M.Footslope Hilly Plains Valley Alluvial fan Mountains Acid rock alluvial colluvium Acid rock colluvium Acid rock alluvium River alluvium Granite residuum Porphyry residuum Granite gneiss/residuum Alluvial soil Red-yellow soil Regosols Gray soil Lithosol ly difference is greater than that of topography, parent materials, etc. C sequestration is possible in upland soil by management practices. 1995~1999 ~ 5~ 9

35 The effect of drainage in upland soils 1 SOC (gc kg-1) Poorly drainage Imperfectly drainage Moderately well d. Well drainage Excessively well d. 1995~1999 ~ 5~ 9 Fig. 13. Chronological changes of SOC by drainage condition of upland soils.

36 The effect of gravel content in upland soils ) (gc kg-1 SOC ~1999 ~ 5~ 9 <% %-35% >35% Fig.. Chronological changes in SOC by gravel content of upland soils.

37 The effect of soil texture in upland soils 1 gc kg-1) SOC ( 1995~ ~ 5~ 9 Fine loamy Coarse loamy Clayey Fine silty Sandy Fig. 15. Chronological changes in SOC by soil texture of upland soils.

38 The effect of effective soil depth in upland soils SOC (g gc kg-1) ~ ~ 5~ 9 <.m.m-.5m.5m-1m >1m Fig.. Chronological changes in SOC of upland soils according to effective soil depth.

39 Upland SOC according soil properties SO OC (gc kg-1) SOC (gc kg-1) ~1999 ~ 5~ ~1999 ~ 5~ 9 1 Poorly drainage Imperfectly drainage Moderately well d. Well drainage Excessively well d. Fine loamy Coarse loamy Clayey Fine silty Sandy SO OC (gc kg-1) SOC (gc kg-1) ~1999 ~ 5~ 9 <% %-35% >35% <.m.m-.5m.5m-1m >1m 1995~1999 ~ 5~ 9 ly difference is greater than that of soil properties.

40 The relationships between SOC and available phosphorus OM (gc kg-1) 5 5. Total-SOC. ~5 ~ 15 ~ 5 3~ 35 ~ 5 5~ 55 ~ 5 7~ 75 ~ 5 9~ 95 ~5 1~115 ~5 13~135 ~5 15~155 ~5 17~175 1~15 19~195 ~ Av. PO5 (mg kg-1) SOC is governed by C input because SOC is related to available phosphorus.

41 Could SOC of upland soils be affected by soil properties? SOC stock of upland soil is related to soil properties. ly difference is greater than soil properties. SOC was low in poor drainage and sandy soil. SOC changes of upland soil were depended on C input. SOC sequestration potential of upland soils Application of compost for beneficial crops made SOC increase SOC sequestration potential of upland soils will be different from soil properties. C sequestration potential will be higher than SOC stock in upland soil. Upland soil could sequester the air C. How much? The answer relies on C sequestration potential and execution policy.

42 Conclusion Chronological SOC change of fields was mainly depended on how much organic matter input. Chronological SOC change of paddy soils seemed to be close to steady-state because of removing rice straw from paddy soils. Chronological SOC changes of upland soils were high in the year of cultivating beneficial crops due to applying compost. C sequestration potential for arable land is prerequisite to increase SOC and regulate C sequestration. Best management practices of increasing SOC are needed to Best management practices of increasing SOC are needed to mitigate air C and to preserve soil fertility.

43 Thank you for your attention