Agroforestry system on peatlands in Pulau Hanaut, Kotawaringin Timur: A win-win solution to preserve peatland functions

Agroforestry on peatlands in Pulau Hanaut sub-district of Kotawaringin Timur is an approach that combines agricultural crops with trees on peatlands. The location of this project is in Serambut and Babaung villages, Pulau Hanaut sub-district. Primary data were collected through Focus Group Discussions (FGD), interviews, and direct observation in the field, and secondary data were collected by studying the related documents that existed. All the data then were analyzed by qualitative descriptive analysis. This site has a peat depth of less than 50 cm and a maximum water table between -10 to -15 cm. Peatland is a unique ecosystem that requires specific considerations for agroforestry practices. Implementing proper water management techniques, such as controlled water levels and irrigation, can help maintain the hydrological balance. Tree species selection that are suitable for peatland conditions were chosen by the communities, such as fruit tree species, cashew nuts, and enrichment planting on the current coconut farm. In addition, fire prevention is also an important part of peatland management. Therefore, zero-burning and organic farming practices should be implemented. Implementing agroforestry on peatlands requires careful planning, considering the unique characteristics of peatland ecosystems, and the ecological, social, and economic aspects of the local community. Local stakeholders’ involvement in decision-making processes is highly recommended to ensure the success of agroforestry initiatives on peatlands in the sub-district, which is part of the Mentaya-Katingan Peat Hydrological Unit, Central Kalimantan.


Introduction
Tropical peatland is one of the most efficient carbon deposits in the world because occupies only 16-17 % of the global peatland area but keeps up to 105 Pg of carbon (C) [1].Indonesia has the largest area of peatlands amongst the countries in Southeast Asia (SEA), up to 13.4 Mha, with 34% of them located in Kalimantan [2].Thus, Indonesia's tropical peatlands play a significant role in maintaining the world's ecosystem C balance [3,4].Also, they have a great potential to be cultivated in providing social and economic benefits to the community [1,3,[5][6][7].
Since a long time ago, peatlands in Indonesia have been utilized for agricultural food crops and plantations by the community.However, the productivity of agricultural plantations growing on peatland 1315 (2024) 012005 IOP Publishing doi:10.1088/1755-1315/1315/1/012005 2 is categorized as low [8].This is due to various natural barriers such as water inundation lasting throughout the year, high acidity, and land variability.Peatlands have also been classified as marginal and vulnerable land that is easily degraded [9].Therefore, only certain commodities, both flora and fauna would be able to grow and live properly on it [10,11].
Peatland cultivation has various adverse risks when it is carried out without taking its nature and characteristics into account [12,13].The conversion of peatlands into agricultural land might disrupt the function of peatland ecosystems as carbon and water stores [14,15].Peatland cultivation still had high conservation, economic, and environmental values when native species (flora and fauna) were introduced into the site [16,17].
One of the forms of cultivating the peatlands sustainably carried out by the community members is the implementation of an agroforestry system [18,19].In short, agroforestry is defined as a form of resource management combining forests or trees with the cultivation of short-term commodities, such as agricultural crops [20,21].Agroforestry is defined as a combination of land-use systems that combines trees and shrubs to enhance productivity, profitability, diversity, and ecosystem sustainability [22].In addition, in the national strategy research of agroforestry in Indonesia, it is stated that agroforestry covers upstream and downstream.
Areas and connect to the industrial and trade sectors.An agroforestry system assists in biodiversity preservation, preserve soil fertility, safeguard water catchment areas, sequesteres carbon, and aids in landscape restoration program [23].Agroforestry has also been defined as a planting pattern where woody plants (trees) are planted on farmers' lands to create ecological interactions between agricultural crops and trees.In this concept, the social as well as the economic aspect play a role in maintaining the farmers' income [24,25].
Paludiculture-based agroforestry might be a sustainable peatland management solution [21,26,27].Peat utilization through the form of an agroforestry model could be carried out without land burning and draining.Small-scale agroforestry practices with limited modifications to drainage patterns have long been able to simply address environmental challenges in meeting livelihood and environmental needs [28,29].One of the promising agroforestry on peatlands conducted by the community or farmers was found at Serambut and Babaung Village, Pulau Hanaut Sub-district, the Province of Central Kalimantan.However, the ecological and socio-economic aspects of agroforestry remain unknown.Therefore, here we studied ecological, social, and economic aspects of agroforestry management applied by the local community on peatland.The objective of this study was to determine the effectiveness of peatland management by the local community through applying agroforestry systems on peatland in Hanaut Island considering the ecological and socio-economic aspects.

2.1.
Research location The research was conducted in Serambut and Babaung Village, Pulau Hanaut, Kotawaringin Timur, Central Kalimantan, Indonesia in February 2023.The research location is shown in Figure 1.

Data collection and analysis
Primary data was collected through triangulation techniques namely Focus Group Discussions (FGD), interviews, and direct observation in the field.The FGD was conducted at village levels, continued by in-depth interviews using questionnaires with key informants to clarify the results of FGD.The FGD and interviews were conducted to gather information about agroforestry practices on peatlands including the commodities that are planted in agroforestry systems.Moreover, biophysical information such as peat depth, groundwater level (instant measurement), and agroforestry system were also directly measured in the field.Secondary data such as Village Potency and statistic data were obtained from literature or any documents related to the research.All the collected data were analyzed by quantitative descriptive analysis.

Description of the research area
Pulau Hanaut is a sub-district in East Kotawaringin Regency, Central Kalimantan, Indonesia.Pulau Hanaut sub-district is one of the 17 sub-districts in East Kotawaringin Regency.Based on its geographical position, Pulau Hanaut District has the following boundaries: in the north -Seranau; in the south -Java Sea; in the west -Mentaya Hilir Selatan Regency; in the east -Katingan sub-district.Pulau Hanaut sub-district is located at Bapinang Hulu village.The village with the closest distance to the sub-district's capital is Bamadu village.Pulau Hanaut sub-district consists of 14 villages.Pulau Hanaut sub-district has an area of 630 km 2 .The capital of Pulau Hanaut sub-district is located at Bapinang Hulu village.Serambut and Babaung villages are among the 14 villages in Pulau Hanaut subdistrict.The peatland area within the villages is classified as shallow to medium categories, with a thickness of between 0.5 to 2 meters.Through simple measurements using peat auger Eijelkamp, it is known that the area has a water level ranging from -10 to -15 cm.
The Babaung village area is a lowland with an altitude between 5-10 meters above sea level (m asl).Serambut village is the second location where data collection and observation of this study were taken.Geographically, Serambut village is located between coordinates of 113 0 3' 1.66" -113 0 5' 56.47"East Longitude and 20 0 6' 56.24" -30 0 0' 51.8"South Latitude.Topographically, Serambut village is in a lowland area.This village is located between a mangrove forested coastal area and a watershed, with an altitude of ± 1 -2.5 m asl.Most of the village area is agricultural land which is rice fields, shrubs, and agricultural commodities with a 100% flat land surface.The average daily temperature in Serambut Village reaches 26 0 -29 0 C and the average rainfall is 1,934 mm year -1 [30].
The land area of Babaung village is mostly forest areas with the status of Production Forest (HP) and Conversion Production Forest (HPK), the rest are Other Use Areas (APL).The peat area in Babaung village is 3,273.13ha or 86.53% of the area of Babaung village, while the mineral area is 367.30ha or 9.71% of the area of Babaung village and the rest is a body of water amounting to 142.06 ha or 3.76% of village area.The peat areas in Babaung village are based on the Decree (SK) of the Minister of Environment and Forestry (MenLHK) No. SK.130/ MENLHK/ SETJEN/ PKL.0/2/2017 concerning the Determination of the National Peatland Ecosystem Function Map, is included in the Peat Hydrological Unit (KHG) area of the Katingan River -Mentaya River which is located at the Katingan Regency and Kotawaringin Timur Regency, Central Kalimantan Province

Socio-economic characteristics of the community
The total population of the Pulau Hanaut sub-district is 17386, consisting of 9020 males and 8,366 females, [31] as shown in Figure 2. The citizens of Serambut Village and Babaung Village consist of a Banjar Dayak ethnic background of 90%, Dayak Ngaju 7%, and 3% other tribes such as Javanese, Madurese, Bugis, and Flores.The livelihood of the community in the area is currently classified into the formal and the non-formal sector.The job occupied by most of the community members is still dominated by the non-formal sectors, such as farmers, fishermen, ranchers, self-employed, and other jobs such as agricultural laborers, construction workers, builders, etc.The livelihood of the population in more detail is in the following Table 1.
In terms of land use, it is mostly used for agricultural land.Due to the reality that most of the existing land type is categorized as peatland, people had to make irrigation canals and ditches to regulate the abundance of water in agricultural land, especially in the rainy season, and as transportation routes, especially to get to the location of the farm and transport all agricultural commodities from the farm to the market.In general, ditches (or the local term is 'handil') and irrigation canals were built leading to natural rivers in Babaung village such as Mentaya river, Babaung Besar River, Babaung Kecil River, and Babirah River.Source: [31,32] Agricultural commodities planted and cultivated in this area are coconut, field rice (rainfed rice), pineapple, vegetables, spices, herbs and medicinal plants (galangal, turmeric, lemongrass) fruit crops such as petai (Parkia speciosa) oranges, durian, rubber and palm oil (Figure 3).Coconut and rubber are the most prevalent crops grown on land owned by a community.Farmers on Pulau Hanaut derive income from the sale of coconuts and rubber.In 2022, coconut and rubber production will reach 2,675,14 and 988,22 tons, respectively [31].The district of Hanaut has been a producer of coconuts for a long time because the quantity is abundant, and they have been sent to the island of Java until the present day.Farmers consider the sale of round coconut to be more profitable because the price is higher than that of copra and its derivatives.After numerous employment opportunities in the plantation sector as daily laborers (workers), a large number of workers are quickly absorbed and paid.The coconut farm is shown in Figure 4.

A.
B.
Area (Ha) Percentage (%) Area (Ha) Percentage (%)  This agroforestry practice usually uses fruit trees and local plants to identify a place with a unique name [33,34].Agroforestry is a tactic that can be used to enhance both the environment and human well-being [21].According to Applegate et al. [35] The approach to restoring, conserving, and developing the hydrology of all peatlands should include the proper combination of commodities and a tree-based system, as demonstrated by the agroforestry model on peatland.
As the population increases, efforts to maintain life while preserving forests, especially peatlands, are obligations that continue to be carried out.At the research site, it can be seen the application of agroforestry elements.Where it is seen that there are land use or land use systems by humans.They use technology in their land exploitation.In this case, the method of land preparation and land processing is carried out in a planned manner by considering seasonal factors and community needs.There is a combination of components of annuals, both woody or annual plants such as Jelutung (Dyera polyphylla), by combining annuals (chilies, cassava, corn, and others).In addition, there is also the keeping of animals or livestock such as chickens [17].
Most of the types of land in the Pulau Hanaut area are peatland, both shallow and medium categories, with a peat thickness of 0.5 meters to 2 meters.In the way to enable the cultivation and utilization of the peatlands for agricultural activities, people of the area then built 'handil' or ditches in their various areas.The activities are carried out to drain peatlands so that they can be planted with agricultural commodities such as corn, cassava, rice, pineapple, etc.In addition, 'handil' making is also intended as access for the community to get to their land as well as bringing agricultural products to the market.
To conduct agricultural cultivation activities on peatlands, people on Pulau Hanaut initially cleared land by burning their land.This is one of the triggering factors of forest and land fires and reported by BPD Damkar Central Kalimantan about the high risk of peatland fire in this region.Fires usually occur in the dry season, where dry peat with low moisture content will sustain fires and result in high emissions [1].By the time they then began to leave slash and burning practice.This is due to the regulations issued by the government that prohibit agricultural land-clearing activities by burning.In addition, there is also a change in the agricultural pattern of the community where they grow many types of perennial trees, such as rubber, fruit trees like durians, stinky bean (petai), palm trees, and coconut trees that do not have to clear their land by burning.
However, rubber and coconut plantations are commodities that cannot provide quick yields for the community.This is because the harvest age of the plants is quite long, which is about 4-6 years.This will certainly make it difficult for the community to meet the needs of their families.Therefore, people then enrich the variety of plants on their land by planting various types of short-lived plants on the sidelines of the perennials they plant on their land.Thus, the community can meet their needs by harvesting and selling the results of the annual crops.
Another challenge faced by the community in agricultural cultivation activities on peatlands is the low level of soil fertility.Peat is formed from organic matter that slowly decays due to continuous waterlogging.This condition results in the acidity level of peat media generally being at a level below neutral or in acidic conditions.Not all types of plants are able to live normally in acidic conditions on peat soils [23].This causes the community to spend greater effort and capital so that the plants they grow can thrive.For example, farmers should add dolomite fertilizer to raise the pH level of their soil so that it is not too acidic.
The various efforts carried out by the community such as combining various types of woody plants with annual plants in the form of agroforestry at Pulau Hanaut are some kind of adaptation to various existing conditions and limitations.As stated by [36] agroforestry techniques arise as farmers' response to limited land owned to obtain periodic and sustainable results.This concept has long been practiced by farmers because it has many advantages.In addition to benefiting the economy of farmers, agroforestry also has important environmental benefits and a broader impact.There have been some challenges in understanding how peatland management and cultivation activities can provide ecological and economic benefits.The management of peatlands by communities on a smaller scale needs to adopt cultivation patterns of natural peat resources that are more environmentally friendly, such as by adapting to existing peat conditions or replacing extractive use patterns [2].

Farmers's preference for plant species
Farmers' current agricultural cultivation practices are an adaptation to limited resources and information.They rely solely on inherited local knowledge from previous generations.To better their standard of living, they require assistance in adopting profitable and sustainable practices [37], [38], seed availability support [39], access to credit, asset ownership, and participation in cooperatives [40].
In general, the respondents within the research area choose plant commodities to be planted both as staple crops and as short-lived crops for several reasons, including to meet household needs.At this point, the reason they choose plant species that they will cultivate is to meet their family needs such as bananas, oranges, mangoes, etc.As for if the results have already been sufficient for the needs of their family, then the farmers also intend to sell them to others.The other factor that many farmers choose in planting certain species is fast yield or harvest.Thus, they will quickly benefit from the yields of the crops so that the capital can be used again for other farming activities.The other reason driving them to plant certain plant/tree species is high selling price factors, such as examples of palm oil and durian types.These two species are well known as they have a very good selling price.
People frequently base their decisions on factors including easy access to marketplaces, consistent prices, simplicity of obtaining seeds, and quick harvests.For a variety of reasons, including to satisfy family, requirements, respondents in the research region selected plant commodities to be planted as staple crops or as transient seasonal crops.In this instance, they chose the kind of plant they would grow based on what their family would require, such as eggplants, chilies, bananas, oranges, mangoes, etc.If the yield is enough to meet the requirements of his family, the farmer also plans to sell it to others.The quantity or speed of the harvest is another element that many farmers consider when planting particular types.As a result, they will obtain the rewards of fast harvesting, generating financial funds for use in future farming endeavors.The high selling price of certain plants and trees, such as durian and oil palm varieties, is another element that motivates people to plant certain types of plants and trees.The selling price of both species is well known.
Fruit trees, such as durian, papaken, and cempedak, are frequently seen on communal properties because, in addition to being used for personal purposes, they can generate cash for the community.The community is especially interested in timber-producing trees since the longer it takes to harvest wood, the more challenging it is.In the area, there are many houses for people and swallow houses; the need for wood is reportedly quite great at the research location.
The productivity and simplicity of plant maintenance are additional factors that motivate farmers in Pulau Hanaut to select crops.Farmers in the research areas confront limitations due to the abundance of pests and diseases, high production input costs, and their limited availability.The reason why people used to prefer coconut and rubber trees was not only because they suited the local soil's requirements, but also because they were simple to care for and had few pests and diseases.Cleaning up weeds is all that is necessary to maintain coconut plants; these plants can still produce effectively even without fertilizer.Every two to three months, there is a harvest season.It is possible to gather coconuts all year long, thus planting coconuts does not depend on the excellent season.Copra is made from coconut after it has been processed, in addition to being marketed as round coconuts.One of the most processed forms of coconut is copra, and its production is conducted using a smoking process rather than sunlight.The same is true for rubber plants; they only need weeds removed to provide good results rather than fertilizing.It is possible to sell rubber plants unprocessed and directly, although the current price of rubber latex is very low, however, the community still earns money for their daily life.Support from the District government of Kotawaringin Timur to improve the economic development of the district is through the issuance of The General Investment Plan of Kotawaringin Timur district year 2019-2025.There are large investment opportunities for rubber, coconut, rattan, and oil palm, where the local communities can take part in the product and value chain [41].

Conclusion
Peatlands have a great deal of potential for agroforestry development because they can reconcile ecological and economic interests, particularly for the people who live near peatlands.The development of agroforestry on peatlands, on the other hand, faces significant obstacles.Community-applicable technologies are selected based on biophysical conditions, market availability, access to high-quality seedlings, and technological simplicity.Agroforestry on peatlands necessitates increased production inputs and peatland-adaptive annual and seasonal plant species.To increase the adoption of agroforestry on peatlands, incentives such as easy access to community seeds for plants adapted to peatlands, expanding the network of products produced from land to a wider market to increase income for the community, and expanding the role of extension workers to provide information and knowledge to the community regarding cultivation techniques on peatlands are required.

Table 1 .
Community livelihoods in the two research locations

Table 2 .
Land use in Serambut village and Babaung village