Preliminary study on C-organic and C-microbial biomass of peatland in Toba highlands

Abstract

Toba highlands is unique and covers a large area. Peat plays an important role as a carbon sink, and is currently utilized for agricultural purposes, use as firewood, and left to degrade. The use of peatlands will impact the maturity of peat, and the emission of carbon dioxides and other gases caused by the decomposition process of microbes. A brief transformation of organic carbon from peat into carbon dioxide negatively impacts the environment, especially in increasing the greenhouse gas emissions. C-organic and C-microbial biomass was observed in peatlands of the Toba Highlands in Humbang Hasundutan, employing the Walkey and Black method, and fumigation and extraction methods to calculate the microbial population involved in the decomposition process or called C-microbial biomass. Moreover, descriptive method were used to map their distribution in the peat areas. The results showed that the highest C-organic was found in barren land at 22.05% and soil C-microbial biomass population was 3.24 µg g−1 soil, whereas the least C-Organic was found in peatland transferred to coffee fields, at 5.23% while the least C-microbial biomass was in peatland transferred to onion fields at 0.28 µg g−1 soil. There was a relatively small amount of organic matter and C-microbial biomass in paddy field, shallots, and grasses. Therefore, the results indicated that converting peatland into agricultural land would likely change the value of organic matter and C-biomass population.

The Unique Toba Highland Peatlands

“…A more recent study by Munawaroh et al (2022) show that the C content of peatlands in Pllung and Dolok Sanngul has declined, with a maximum of 22% on an open peatland (with no vegetation) and 5% on coffee fields.…”

“…Soil properties of peatland in Pollung and Dolok Sanggul with different land uses( Munawaroh et al, 2022) …”