Data uncertainties and limitations
It is clear that there are uncertainties related to the scoring of each crop. We score each indicator by crop based on integrated assessment of literature, expert knowledge and stakeholder engagement. However, in reality there were differences between sites, as a function of local environmental and socio-economic characteristics, which were not considered in this study. For example, profitability for smallholders was depending upon the local prices, which might vary considerably between areas (and season). In addition, our emission factors assumed a certain drainage level per crop, but in practice each crop was grown under a range of drainage conditions. Where peatlands were already drained before planting by smallholders, it was unlikely that farmers would increase the water levels to the maximum level that the crop could sustain (see also Giesen and Nirmala 2018). We had noted in several villages that many crops, for example rambutan, durian, dragon fruit, pineapple and melon, were sometimes grown at deeper water tables than assumed in our study (water spinach was an exception as it required near sub-merged condition). Furthermore, there was variation in the degree to which fertilisers and nutrients were locally used, and in this study we did not account for their effect in speeding up decomposition contributing to CO2 and N2O emissions (Leifeld and Menichetti Joosten et al. 2016; Osaki et al. 2016). Hence, our scoring should be seen as indicative yet useful in terms of assessing the barriers to the cultivation of the individual paludiculture and non-paludiculture crops in the peatlands.
Another important limitation of our study is that we assessed the crops in isolation whereas in reality the smallholder farmers often plant a combination of crops in order to spread risks, diversify income and spread food availability throughout the year. Intercropping might reduce some of the disadvantages of planting individual crops. For example, sago could be grown in combination with vegetables that could provide an income early in the cropping cycle. On the other hand, intercropping might increase CO2 emission as farmers often create ridges to accommodate crops that need dryland. We also excluded non-food crops such as jelutung resin (Dyera sp.) which could be grown as industrial plantations without draining the peatlands (Giesen and Nirmala 2018). Hence, opportunities for promoting sustainable livelihoods in peatlands are larger than what we present in this paper.
Restoring the degraded peatland for paludiculture incurs costs for hydrological restoration and revegetation, which may range from US$400/ha to US$25,000/ha depending on the level of degradation (Hansson and Dargusch 2018). As mentioned previously, these costs were not considered in our analysis. Given the national and international significance of the health and environmental impacts of peatland drainage, and given that the drainage was in most cases not started by local people, it seems reasonable to assume that local smallholders would not bear the costs of peat restoration. Indeed, at the moment, the Government of Indonesia is pursuing peatland restoration funded from the national budget. Other opportunities for funding restoration relate to (national and/or international) carbon credits. However, in many cases, peatland restoration can only be successful if followed by profitable peatland use which provides local incentives for controlling fires and abstaining from renewed drainage. These incentives will require some forms of paludiculture.
Opportunities and bottlenecks for paludiculture development on peatland areas
In Central Kalimantan, the conversion of peat to croplands and plantations is still ongoing. To illustrate this trend, in the year 2000 around 144,500 ha of peatlands was used for cropping and this increased to 241,408 ha in 2014 (an increase of 40%). In 2017, this increased to 702,408 ha, which was nearly a fivefold increase in 17 years (Uda et al. 2017; MoEFRI 2018). In 2017, the total area of protected peatland only covered about 55% of the total area of peat hydrological units (PHU or Kawasan Hidrologi Gambut/KHG) in Central Kalimantan (MoEFRI 2018). A crucial element for better managing Indonesian peatlands is to stop the ongoing conversion of peatlands. Drainage always leads to high CO2 emissions, and, once drained, the rewetting of peatland (which is done through a mix of canal blocking, fire control and rehabilitation of the vegetation) is a very difficult and expensive task (Hansson and Dargusch 2018; BRG 2019).
Whilst more regulations are in place nowadays for plantation companies, there are currently little controls and support mechanisms for smallholder farmers. Smallholders would need to be supported with the planting of crops that require no or limited drainage. In this study, we focus on food crops. Seven crops are tolerant to at least temporary inundation (e.g. sago palm, illipe nut, water spinach, kelakai edible fern, banana, snake fruit, mangosteen) while others warrant strict water management or limited drainage. Some crops are not recommended for scaling-up to plantation-based systems because there is only a limited market for them (e.g. bitter gourds, water spinach, kelakai edible fern). Therefore, in a landscape approach to peat management, it is important to separately assess the recommended species for the farmers/communities and the plantations (Giesen 2013). In our paper, we focus on the community-based farming. We find that peatland uses by indigenous farmers are mostly a long continued heritage (e.g. durian, rambutan, illipe nut, mangosteen) while other ethnic farmers (e.g. transmigrants from Java, Bali or Sumatra) tend to be somewhat more open to introduce new crops such as dragon fruit, snake fruit, sweet melon, liberica coffee, candlenut, etc. in the peatlands. Further insights into the opportunities and barriers for the cultivation of paludiculture food crops are presented in Online Appendix 4 Supplementary Material.
We found that market demand and access to market were the most important factors for farmers in choosing the crops. Currently, crops are grown, in particular, for local village markets with some crops traded on provincial markets, e.g. in Palangka Raya, the province’s capital. There are no connections to international markets yet, and there are several obstacles to scaling up production. First, villages are spread over large areas and each village only has a limited production capacity. Second, infrastructure in many parts of the province is still relatively poor. Third, technology and facilities to help local farmers maintaining, harvesting and processing their crops are still lacking. Before their export ban in 2012, illipe nuts were in high demand in international markets. The ban was meant to encourage the development of downstream industry, as also expected with the export ban of raw rattan (MOTRI 2012), but until now the development of the downstream sector has not yet occurred. Another obstacle to the export of food products is that products often do not meet the standards required for export (Moïsé et al. 2013). Thus, scaling up should involve establishing supply chains, linking traders to markets and support for farmers to enhance the quality of their produce. It may be most practical to first focus on scaling up to national markets before promoting export.
Some regencies in our study area have already developed a number of community trials for crops in the peatland restoration areas (e.g. sago in Pulang Pisau regency, dragon fruit in Palangka Raya), and have initiated some new plantation trials (e.g. philippine-tung/kemiri sunan (Reutealis trisperma), tamanu/nyamplung (Calophyllum inophyllum) plantations in Palangka Raya, Pulang Pisau regency and Katingan regency) (CIFOR 2016). These trials showed that these crops could grow well in degraded and burned peatlands, including in agroforestry systems as well (Maimunah et al. 2018).
We also note that swamp rice farming may be an alternative opportunity in the (degraded) peatlands in Indonesia (Surahman et al. 2018) as there are some recommended rice varieties which are adaptive to peatlands conditions (e.g. Inbrida Padi Rawa/Impara, IR42, IR64, IR66, Kapuas, etc.) (JICA 2017). Nevertheless, rice farming may not be practical in many peatland areas in Central Kalimantan given the specific requirements for water level control and tillage, soil amelioration and fertilisation. Furthermore, the market price of the swamp rice varieties is often lower than the market price of local rice varieties grown on mineral soil (e.g. Siam unus, Lemo, and Pandak) because local communities prefer the taste of these local rice varieties (in line with Surahman et al. 2018; Noor et al. 2014). Finally, rice cultivation still requires drainage during part of the season and is in that sense also not a true paludiculture crop (Noor et al. 2014; Giesen and Nirmala 2018). For these various reasons we hypothesise that swamp rice may have limited potential in Central Kalimantan, but we acknowledge that swamp rice may potentially be more suitable in other provinces.
We believe that sago is a particularly promising paludiculture crop. The market is potentially very large as sago can be used for local and national food production and can also be turned into starch for export, or be used to produce bioplastic and bioethanol (Nishimura 2018). In principle, Indonesia can produce the raw material for plastic bags and other packaging materials both for national use and for export from domestically grown sago in peat, thereby resolving two major challenges (peat degradation and marine and coastal plastic pollution) in one go. Sago also has other applications: different parts of sago palm can be used for food (the young stems can be cooked), construction and weaving crafts materials, food pellets ingredients for poultry and fishery farms, biomass (ethanol made from sago), growing media for Volvariella volvacea mushrooms and breeding Rhynchophorus larvae which is a good source of protein (JICA 2017). Cultivation of sago in Riau is already locally very profitable, with revenues from mature sago stands of up to 1500 euro per ha per year (Orentlicher 2019). However, a main factor that might hinder farmers to cultivate sago palm is the time to wait before the first crop can be harvested (at least 8 years but sometimes up to 12 years; TECA 2015). Once the sago is mature harvesting can take place every year and unlike oil palm there is no need to replant after 25 years or so. Sago grows well in undrained, shallow peat (up to 3 m) but is less productive in deeper peat. Hence, it is urgent that: (i) we examine how sago productivity can also be maintained in deep peat; (ii) fast growing sago varieties are developed; (iii) cropping systems are developed that combine growing sago with intercropping in the first 8 years or so; (iv) we examine if and how farmers (or plantation companies) can get financial or other support to overcome the period of 8 years with less income (e.g. in the form of carbon credits or government subsidies); and (v) there is further testing of the potential to use sago for various non-food applications in particular bioplastic and bioethanol.
The Indonesian Government has been promoting the protection and sustainable management of peatland ecosystems through a number of regulations including the 2016 National Government regulation PP No. 57 on peatland ecosystems protection and management (Indonesia Government Regulation 2016). The government has prescribed 3 m peat depth as the main criterion for distinguishing between protected and development peatland areas and a water table of deeper than 0.4 m as the criterion for damaged peatland area. Issues remain with regards to implementation and enforcement of the regulation, identifying where the boundaries between deep and shallow peat are, and dealing with the hydrological connectivity within peat domes as draining shallow peat may also affect deeper peat layers in the same peat dome. In addition the externalities from draining peat between 1 and 3 m are similar in scope and magnitude as those in deeper peat, except for the shorter time period during which they occur before the peat has disappeared.
Compared to the “traditional”-drainage-requiring crops (such as oil palm, acacia, and rubber), paludiculture crops are currently less attractive to farmers either because of lower profitability, limited market opportunities or more complex farming requirements (see also Joosten et al. 2016; Sumarga et al. 2016; Giesen and Nirmala 2018). The adoption of paludiculture will therefore depend greatly upon policies and regulations imposed by the Indonesian government. A potential way forward is to ban the planting of oil palm on all peatlands (hence including shallow peat), and to provide support for paludiculture in degraded peatlands by promoting local trials, farmer visits to these trials, farming training and making seedlings available to farmers. The barriers described in the previous section are very different for each of the paludiculture crops. The promotion of paludiculture needs to consider these barriers to fine-tuning the technical support to farmers. Options specific for different crops include providing post-harvest technology to farmers to increase product quality; training and support for establishing facilities for local processing of foods (e.g. sago noodles, banana chips, etc.) and financial support for farmers planting crops which need a long-time period before the first harvest (such as sago). We provide further details in Online Appendix 5 Supplementary Material.
We also believe the export bans on raw illipe nuts and rattan should be revoked as soon as possible. Local farmers had long been cultivating illipe nuts due to high demand in the international markets until the export ban in 2012. Rattan is a profitable crop (before the export ban) that can be grown as an understorey species in peatland forests without drainage and as an understorey crop in secondary forests (Sumarga et al. 2015). The bans on the export of illipe nuts and rattan have been in place for 8 years (MoTRI 2012) but there are still no signs of domestic illipe nuts and rattan industries emerging while the ban suppresses the illipe nuts and rattan prices and thereby the income of farmers who are protecting the peatland forest through their illipe nuts cultivation and rattan farming.
Note that, in addition to supporting farming activities, there is also a need to look at peat domes in an integrated manner, particularly in terms of maintaining high water levels across the domes. Large plantation companies operating in peatland generally manage water levels within their own plantations. However, ensuring effective water management is also a major issue for smallholder farmers as individual farmers only have limited means to control the water levels in their fields. Water management, including in peat domes, fall under the Ministry of Public Works, and their support is essential in ensuring a transition to paludiculture, particularly in relation to the rehabilitation and sustainable use of peat for smallholder cropping.
It is important that more efforts to introduce, test, develop and scale up paludiculture crops are started as soon as possible. It is a major undertaking to rehabilitate millions of hectares of degraded peatlands and, over time, to replace oil palm on peat by other profitable crops that can be grown on peat without drainage (or with low drainage). Shifting towards profitable, inclusive and sustainable peatland management involves steering the investment and land management decisions in both plantation companies and smallholders in such a way that further drainage is avoided and there is a gradual replacement of crops that require drainage with the crops that can grow in the peatland without drainage. A main bottleneck in this effort is a lack of options to replace oil palm by other profitable and sustainable crops suitable for peatland. Local contexts may provide opportunities for different paludiculture crops, depending upon for instance access and proximity to markets, seeds availability, farmers’ preferences, etc. Paludiculture crops may also generate profits through carbon trading which, in turn, will support Indonesia to achieve its national contribution to the Paris Agreement (i.e. to reduce its GHG emissions up to 29% by 2030 (INDC 2015). In this context, it is important that the communities as well as the regencies/districts that have successfully managed their peatlands are recognised and rewarded for their contributions to sustainably maintain the peatlands. A fiscal policy that integrates ecological and social aspects into the intergovernmental fiscal transfer instruments should be considered to promote and support the sustainable development in peatland areas (e.g. provide general-purpose transfer (Dana Alokasi Umum, DAU), specific-purpose fund (Dana Alokasi Khusus, DAK), and/or shared revenue fund from taxes, non-taxes and/or natural resources (Dana Bagi Hasil, DBH)) (Cadman et al. 2019). Lastly, it is crucial to keep and better enforce the existing policy of “no drainage” on the peatlands, extending this to shallow peat. It is already a major and increasing challenge to deal with the continued subsidence and fires in currently drained peatland (Hooijer and Vernimmen 2013).