Estimation of soil carbon stocks in Malaysian soils and the implication on the carbon balance in oil palm cultivation.

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1 Estimation of soil carbon stocks in Malaysian soils and the implication on the carbon balance in oil palm cultivation Yew Foong Kheong

2 Presentation Common Malaysian mineral soils cultivated with oil palm and main characteristics Their global and regional classification Amount of carbon stocks in these soils Carbon stock variation with soil depth Amount of carbon stocks in oil palms Carbon stock ratios (soil: plant) Oil palm cultivation increases soil carbon stocks Conclusions

3 Choice of soils 12 soils with at least 15 profiles each (Law and Tan: Department of Agriculture) Mean soil carbon values used in estimation of soil carbon stocks Mineral soils Common oil palm growing soils Variety of soils Coastal to interior upland soils

4 COASTAL Soil Taxonomy: Tropaquept FAO Legend: Gleysol Sabah: Metah Sarawak: Samarahan Features: flat marine alluvial plains, clay, imperfectly drained

5 Soil Taxonomy: Fluvaquent FAO Legend: Gleysol Sabah: Weston Sarawak: Punda Features: mouth of large rivers meeting sea, mixed riverine and marine alluvial clays, clay, imperfectly to poorly drained

6 RIVERINE Soil Taxonomy : Paleaquult FAO Legend: Sabah: Inanam Sarawak: Bijat Acrisol Features: low lying river terraces, clayey, deep, fluctuating high water table

7 Soil Taxonomy: Paleudult FAO Legend: Nitosol Sabah: Pegalan Sarawak: Kayan Features: flat riverine alluvium, sandy clay loam, deep, somewhat excessively drained

8 Soil Taxonomy: Paleudult FAO Legend: Nitosol Sabah: Kinabutan Sarawak: Abok Features: upland soil, granite, deep, sandy clay to clay, well drained

9 Soil Taxonomy: Hapludult FAO Legend: Acrisol Sabah: Kumansi Sarawak: Jakar Features: upland soil, sedimentary rock, clay, deep, moderately well drained

10 Soil Taxonomy: Paleudult FAO Legend: Nitosol Sabah: Tanjong Lipat Sarawak: Bekenu Features: upland soil, sandstone, sandy loam, deep, somewhat excessively drained

11 Soil Taxonomy: Haplorthox FAO Legend: Ferralsol Sabah: - Sarawak: - Features: shallow, lateritic, clay, well drained

12 Variation of Soil Carbon Content with Soil Depth Briah 150 cm SOILS Linau Chat Rengam Org C (%)

13 Range of soil carbon stock values 192 t C/ha 41 t C/ha (5 X) 192 Mg C/ha Lateritic upland Coastal

14 Carbon stocks in Malaysian soils Tonnes 140 C /ha (65) (177) Marine alluvial Riverine alluvium (60) Upland soils

15 Range of soil carbon stock values (t C per ha) (177) (65.4) (59.7) Coastal Riverine Upland

16 Carbon stocks in oil palms (tonnes C per ha) t C/ha Ex situ In situ Total th year 10th year 15th year 20th year 25th year Henson s model In situ contributes to soil C

17 Comparison of oil palm with agroforestry Crop and region Oil palm (5 th YAP) Oil palm (20 th YAP) Agroforestry (semiarid)* Agroforestry (subhumid)* Agroforestry (humid)* Agroforestry(temperate)* Plant C stock (t C per ha) *Source: Montagnini and Nair

18 Ratio of C stocks (oil palm to soil) Ratio Briah Holyrood Rengam Tavy 0 5th year 10th year 15th year 20th year 25th year

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21 Avenue 65% Palm circle 15% Frond area 20%

22 Soil C content C % years 10 years 20 years Palm circle Avenue Frond piles

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26 Increase of soil carbon stock with oil palm cultivation Years after planting Carbon stocks (t C per ha) (2 x) (3 x)

27 Oil palm cultivation enriches soil Time carbon stocks Least disturbance (No tillage or minimal tillage practices) Some erosion losses and loss of carbon stock which is richest in top soil particularly with heavy tropical rain Oil palm is perennial - land clearing and soil disturbance once every years

28 Conclusions Carbon stocks of wide range of mineral soils from the coast to interior (upland) studied Soil carbon stock varies from 41 t C per ha (lateritic soil) to 192 t C per ha for coastal marine soil Mean soil carbon stocks (t C per ha) are coastal 177, riverine 65 and upland 60 carbon stocks decrease with depth for upland but not for coastal soils

29 Conclusions Carbon stocks of oil palm increase with age due to increasing biomass and yield Peaks at 20 th YAP Most carbon stock of OP found in situ (standing biomass, pruned fronds) Therefore has great potential to increase soil C stock 23.9 t C per ha at 5 th year to 45.3t C per ha at 20 th year

30 Conclusions Ex situ OP carbon stock varies with FFB yield 6.8 to 6.0 t C per ha at 5 th and 20 th year respectively OP: soil carbon ratio increases with age Soils with high C: ratio increases from 0.1 to 0.3 during period Soils with lower C, ratio increases from Major inland soils, ratio In OP ecosystem, OP contains almost as much C stock as soil

31 Conclusions Soil carbon stock increases with time in oil palm plantation Highest soil carbon increase in frond rows Oil palm is perennial tree (25-30 years life cycle) Does not need annual land preparation and removal of top soil (highest C content) Oil palm cultivation can increase soil carbon stock

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