CO 2 Measurement in Palm Oil Plant in Peatland

Peatlands are one of the contributors to greenhouse gas emissions because it is estimated that the carbon stock stored in them is around 528 Giga tons (Gt) or equivalent to 75% of the total carbon (C) in the atmosphere, so that if peat is oxidized it will cause carbon to be released into the air. The conversion of forest land to agricultural land can be one of the causes, including the activity of making drainage channels. The construction of drainage channels causes a decrease in the water table so that the volume of peat under aerobic conditions increases while increasing the activity of microorganisms in decomposing peat. Peat decomposition and root respiration contribute to carbon emissions. This study aims to determine the CO 2 concentration in several conditions of oil palm roots. CO 2 measurement by survey method on oil palm plantations, using the IRGA (Infra Red Gas Analyzer). Measurements are carried out once per month from January to May 2020 for 3 minutes. The point of observation was determined by 2 factors with 3 treatments and 3 replications. Factor 1 is the observation point in the area of accumulation of midrib pieces and other litter (B1) and factor 2 is the observation point in the road area around the tree (B2). While the treatments were (A1) natural roots, (A2) roots were cut when the measurements were going to be taken and (A3) roots were cut and permanently restricted. The results of the measurement of the highest average concentration of CO 2 changes from 0 minutes to 3 minutes in January were in treatment B1A3 (140.4 ppm), February in treatment B2A3 (103.9 ppm), March B1A3 (124.6 ppm) ppm), April B1A3 (143.8 ppm) and May B1A3 (110.7 ppm). Meanwhile, the lowest concentration of CO 2 changes from 0 minutes to 3 minutes in January was in treatment B1A1 (71.5 ppm), February in treatment B1A1 (25.7 ppm), March B2A3 (40.2 ppm), and March B2A3 (40.2 ppm). April B2A1 (30.6 ppm) and May B1A1 (43.2 ppm). From the measurement results, it can be concluded that the highest concentration of CO 2 and its changes was in treatment B1A3, namely in the treatment of cutting roots with permanent blocks, while the concentration of CO 2 and its reduced changes was in the treatment of natural roots (A1) both in Blocks B1 and B2.


INTRODUCTION
Climate change is a global phenomenon caused by human activities such as the use of fossil fuels and land use change, the process produces gases such as CO2, CH4 and N2O.These gases are increasing in number in the atmosphere and have the ability to absorb and reflect long-wave radiation emitted by the earth, resulting in an increase in the earth's temperature by 0.6oC during the 20th century (IPCC, 2007).The gases that play a role in global warming are known as greenhouse gases.One of the contributors to greenhouse gas emissions is peatland and it is estimated that the total world carbon content stored in the soil is 550 Giga tons or equivalent to 75% of all carbon in the atmosphere (Joosten, 2009;Ansari, 2011).This is because peat soil is formed from the accumulation of organic matter with a slow rate of decomposition so that the entire peat is a stored carbon source that plays a significant role in the global carbon cycle.When peat soil is oxidized, it will release carbon into the air not only in the form of CO2 but also CH4 which is produced from anaerobic breakdown of organic matter.Peatlands require good water management for several reasons.First, for nature conservation and restoring hydrological conditions, such as reducing the vulnerability of peatlands to fire.Second, water management is needed so that peatlands can be used for agriculture such as rice, oil palm, vegetables, pineapple, and others.Annual crops (food and vegetables) generally require shallow drainage ranging from 20-30 cm.For oil palm plantations the ideal drainage depth is around 50-70 cm (Melling et al., 2005) and for rubber plants around 20-40 cm (Agus and Subiksa, 2008).
Maintaining a water level of no more than 40 cm from the soil surface will result in a balance between reducing CO2 emissions and water for plant growth (Sabiham et al., 2012).The purpose of this study was to determine the concentration of CO2 in oil palm plantations on peatlands.

MATERIAL AND METHOD
The measurement location is in Teluk Panji Village, Kampung Rakyat District, South Labuhanbatu Regency.Implementation time starts from January -May 2020.The observation point was determined by 2 factors with 3 treatments and 3 replications.Factor 1 is the observation point in the area of accumulation of midrib pieces and other litter (B1) and factor 2 is the observation point in the road area around the tree (B2).While the treatments were (A1) natural roots, (A2) the cut roots are 50 tertiary roots and 50 quaternary roots when measurements were going to be taken and (A3) roots were cut and permanently restricted (Figure 1).CO2 measurements were carried out using a survey method on oil palm plantations, using an IRGA (Infra Red Gas Analyzer) for 3 minutes.Determination of the measurement location area is carried out using the purposive sampling method, namely the determination of the location intentionally which is considered representative.

RESULTS AND DISCUSSION
The data on the average CO2 concentration measured in January, February, March, April and May are shown in Fig. 1 -5.

Figure 5 .
Figure 5. CO2 concentration in May 2019.Information: B1A1 : Litter area with natural roots B1A2 : Litter area with roots cut during measurement B1A3 : Litter area with cut roots permanently restricted B2A1 : Ordinary Road Area with natural roots B2A2 : Road area with root cut off during measurement