Soil and carbon sequestration : the start of carbon footprint assessment

For the response to global warming and related problems to be successful, it must be directed not at single issues such as poverty alleviation, reforestation or biodiversity conservation, but rather at a more systematic change in the incentive mix to encouragecapital flows to the people and businesses that live and use land that is likely to be degraded from an ecological point of view. The potential exists for the plantation companies to combat climate change by sequestering a lot of the additional carbon (C),that has accumulated in the atmosphere since 1800, into the tropical soils and vegetation, while at the same time address poverty eradication and improved biodiversity conservation. The technologies necessary for such a change in land use together with the best agricultural practices are available for financial investment into bio-sequestration to strip enough C02 out of the atmosphere, thereby helping to avoid catastrophic climate change. Bio-sequestration is associated with the cooling effect of trees; firstly, by reducingatmospheric greenhouse gases (GHG) and hence global warming; and, secondly, by increasing evapo-transpiration from a bigger leaf area, hence more cooling. Bio-sequestration as an outcome of plantation tree crops like the oil palm would require emphasis on the bio-systems that sequester C in soil and vegetation. Bio-sequestration in oil palm plantations is one of the better options to reduce atmospheric C02 due to its steady sequestration over a lifespan of 25 years as oil palm covers a large area amounting to 4.48 million ha (in 2008) in the country. The paper examines examples from some of the 14 major soil groups in Malaysia for their C stocks. As the soil C stock varies with soil depth, data at various strata of 0-15, 15-30, 30-45, 45-60,60-75, 75-90 and 90-105 cm were examined for their bulk densities (ED), total C and nitrogen (N) concentrations (%). Total soil organic C includes both organic C and inorganic C forms. Soil C is expressed as a concentration (%) or as a stock (t/ha). Total soil C stocks were determined by multiplying the C concentration (%) by the bulk density (g/cm3) for each depth down to 1 m. The measurement of tonnes of CO2 equivalent per hectare (t C02-eq/ha) was calculated by multiplying with 3. 67 to get the C stock in t C/ha. Comparisons were made of C stocks in marine alluvium, riverine alluvium and upland soils to obtain their ranges of C stock values in t C/ha. Measurements were also made of the C stock in oil palm over the 25 years of sequestration. Finally, the C stocks in the soil and vegetation were compared over three generations of palms on a selected soil type.The soil C stock was found to vary over the palm .circles, along the avenues and under the frond piles. Generally the use of oil palm as a bio-sequestration agent results in an increase in soil C stock over each cycle of25 years. Non-tillage of the soil when palms arereplanted further enhances the soil C. The agro-biodiversity in oil palm plantations in both above- and below-ground is discussed to supplement the claim that oil palm planting enhances biodiversity. It is concluded that oil palm is a good sequester of C in Malaysiansoils, and some policy recommendations are suggested.