[LANDMARC] What is soil organic carbon (SOC) in Indonesia?

For EU's LANDMARC project, Indri from the su-re.co Think team has written a summary of soil organic carbon (SOC) in Indonesia which can be found here. Increasing SOC is a much more powerful way of mitigating climate change than reducing carbon dioxide emissions, as it traps carbon in the air into the soil!

＝＝＝＝

Waste management is another sector identified as a national priority related to soil carbon enhancement (SCE) activities. The government has set a target of reducing waste emissions by 94% from 2024 to 2030, which has high potential. Anaerobic digestion processes currently contribute to Indonesia's GHG emissions, but compost and other measures of integrated sustainable waste management systems have enormous potential. Furthermore, enhancing soil organic carbon (SOC) in the agricultural sector can be an effective negative emission measure. Out of the total agricultural land of around 62.3 million ha, which makes up approximately one-third of the total Indonesian land surface area, about 82% is occupied as cropland, including land for temporary crop cultivation (arable land) and permanent crops (FAOSTAT, 2020). For instance, adding only 1%-point of the SOC to the agricultural area could provide a significant storage potential.

Despite the importance of organic matters in soil, data for evaluating SOC change in Indonesia is limited due to regular monitoring for SOC stock and changes. Although SOC change data at the macro-level (nationwide) is not available, several studies report SOC depletion in Indonesian soils at the micro-level. One study suggested that SOC stock declined by around 30% when a forest is converted to agricultural production (Murty et al., 2002). A study discovered that the level of organic matter in the 0-15 cm soil of lowland rainforest in Sumatra decreased by 48.1 Mg C ha-1 when the forest downgraded to grassland (Santoso et al., 1997). Another primary source of soil carbon reduction in Indonesia is the loss of carbon from organic soil (peatland), which covers about 14.9 million ha and contains exceptionally high carbon content ranging from 420 to 820 Mg C ha-1 (FAO and ITPS, 2015).

＝＝＝＝

This is too long for one blog post, so I'll continue tomorrow.