A few days ago our team traveled to an oil palm plantation company for a drainability assessment. This activity was carried out because it was alleged that the company’s HGU area contained peat land areas in it. In order to be able to carry out an assessment, information on peat depth is also needed, so that in addition to the drainability assessment, we also carry out a peat inventory. We conducted a peat inventory using a 13-parameters guideline based on Minister of Environment and Forestry Regulation No. 14 of 2017 concerning Inventory and Determination of Peat Functions. One of the 13 parameters which is the presence of pyrite layers and their depth. For those of you who are curious about what “Pyrite” really is, let’s look at the article below. 

Pyrite is a mineral of the FeS2 compound which is commonly found in swamps, especially in areas affected by tidal influence, generally found in the estuaries of rivers. Pyrite itself is formed due to the interaction between seawater which contains a lot of sulphate-rich materials (SO42-) and soil or river water which carries a lot of sediment which has abundant iron (Fe)-oxide content. To speed up the pyrite formation process, sulfate reducing bacteria are needed which require organic matter as their energy source. The results of bacterial respiration produce sulfide which will then interaction with iron to produce FeS2. Therefore, pyrite will very easily form in estuarine peatlands, the three constituent components are very abundant.  

The presence of pyrite can be identified through several conditions such as the presence of purun plants, yellow spots due to oxidation of iron on lumps of soil or former trench excavations, or blackish gray in stagnant conditions and smells bad due to the smell of sulfur. To be more accurate, the soil that is thought to be pyrite is dripped with hydrogen peroxide (H2O2). Soil containing pyrite will foam explosively, the more foam produced indicates the higher pyrite content.