Ini Penampakan Lahan Rawa untuk Pertanian di Kalsel/Foto: Istimewa/Kementan

The Potential of Swamplands in Improving Indonesia’s Food

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Topik Pembahasan

Food estate or food barn project by utilizing swamplands being developed by the government has been one of the efforts to anticipate the threat of food crisis. The optimization of swamplands is considered a breakthrough to secure domestic food supply so that the people’s needs can be fulfilled independently. 

Swampland is a land that exists along watersheds, beaches, and inlands. It is found in the hinterland up to 100 kilometers and is influenced by tides or rivers. There are two types of swampland in Indonesia; tidal swamp and non-tidal or inland swamp. Tidal swamp is a land that is directly or indirectly influenced by tides. The latter is a land that is inundated by water for more than three months with the lowest height between 25-50 centimeters. 

Swampland is a marginal land that has enormous potential to be utilized for agriculture including food crop farming. Its land area reaches around 34.12 million hectares (ha), spread in Kalimantan, Sumatra and Papua. However, the area that has been opened by the government integrated with the transmigration program is only about 2.27 million ha, while that has been opened by local communities independently is 3 million ha. 

Swampland clearing is generally used for rice cultivation. According to the Indonesian Center for Agricultural Land Resources Research and Development (BBSDLP, 2015) the potential swampland area for food crops (rice paddy) reaches 14.18 million ha. It is estimated that only about 6 – 6.5 million ha of the area has been utilized and only about 3 – 3.5 million ha has been converted into rice fields. The rest are still in the form of shrubs, secondary forests or monotonous swamps that are always inundated throughout the year. 

Judging from the physical aspect of the environment, swamp areas are generally a specific and fragile ecosystem with distinctive land and hydrological characteristics. Therefore, it requires careful handling in their development. Most swamp areas have barriers for agricultural development, in the form of peat layers with varied thickness, sulfuric acid, saline intrusion, and flooding risk. 

During a webinar discussion of the Agricultural Journalists Forum (Forwatan) with the theme “Food Estate Supports Food Security” in Jakarta, Thursday, March 18, 2021, the Director General of Agricultural Infrastructure and Facilities (PSP) of the Ministry of Agriculture (Kementan), Sarwo Edhy, said the government is encouraging land intensification on land swamps through technological approach, socialization to farmers to use certified quality rice. 

How to Manage Soil Fertility in Swamplands with the Help of Biofertilizer

The productivity of swamplands is very diverse and highly dependent on soil conditions, water management and the application of technology, especially land management and plant varieties. Based on land typology, the productivity of existing rice paddy ranges from 3.2 – 4 tons GKG/ha in potential acid sulphate lands, 2.6 – 3.5 tons GKG/ha in actual acid sulphate land, 2,7 – 3 tons GKG/ha in peatlands, and 2.6 – 3.9 tons GKG/ha in saline land. 

Behind the potential, swamplands have many obstacles. Their main obstacle is the high acidity of the soil, especially in acid sulphate swamplands. Consequently, the average productivity of rice in swamplands is low, only 2 – 3 tons/ha. The productivity is half or less than the average national rice yield of 6 tons/ha. As a result, many swamplands are left abandoned as idle lands. 

According to Mukhlis, a researcher from the Research Institute for Swampland Agriculture, as quoted from technology-indonesia.com, the important strategy in swamplands is to provide organic materials as soil enhancer. Organic materials become a biological buffer that plays a role in improving the physical, chemical, and biological characters of the soil so that it can provide nutrients in balanced quantities. 

In order to achieve this goal, the organic materials must have decomposed or have a low C/N ratio. Fresh organic matter that is directly applied to the soil can be detrimental to crop growth because of the immobilization of nitrogen and the release of toxic compounds that interfere with plants. 

Mukhlis further explained that farmers in swamplands generally use straw or weed residues as organic materials. However, they contain high cellulose with high C/N ratio that would result in a long decomposition process. 

To date, farmers have been using straw as organic fertilizer in two ways. First, by spreading it to the rice field directly when harvesting, continue with spraying water until the field is flooded. Second, the straw should be composted first before spreading it to the land. 

The direct utilization could be very profitable to save costs and labor, but the straw is decomposed for more than one month. 

The Agricultural Research and Development Agency (Balitbangtan) has succeeded in searching for innovations and technology for Biotara biofertilizer which contains Trichoderma Sp. as a decomposer. After the straw is distributed to the plots, Biotara is spread out so that the remodel could run faster. Biotara also remains effective in acidic and inundated swamps because it is selected from superior microbes in swamplands. 

Farmers can get other benefits because Trichoderma in Biotara can control soil borne diseases. Biotara is also enriched with P-solvent microbes Bacillus sp, and N-tether Azospirillium sp that live in swamplands. Like other biofertilizers, Biotara can increase soil fertility, save fertilizers, increase yields, and reduce environmental pollution. 

Based on a research by Balitbangtan, the three microbes in Biotara can increase the efficiency of nitrogen and phosphorus fertilization by up to 30% and increase rice yields in swamps by 20%. So, with Biotara biofertilizer technology, it is not impossible to turn swamplands into productive rice fields with a yield of 6-7 tons/ha. 

This possibility is acknowledged by Ubed, a tidal swamp farmer in Sido Mulyo Village, Anggana district, Kutai Kertanegara, East Kalimantan (Kaltim), who obtained 6.8 tons of GKG/ha by using Biotara. Before that, the average yield only reached 5 – 6 tons of GKG/ha. In addition, Biotara can save the use of chemical fertilizers, only 2/3 of the recommended dose. 

Swamp Farming Uses Adaptive Rice Varieties 

In addition to the application of appropriate and integrated land management technology, it requires adaptive rice varieties in optimizing swamplands. Until 2017, the Balitbangtan has prepared various innovations, including by producing a number of high-yielding rice varieties that are adaptive in tidal swamps and inland swamps. There are a total of 35 varieties of superior rice adapted for tidal and inland areas with various superior characters. 

As an example, Balitbangtan of the Ministry of Agriculture has held demonstration farms in Pulang Pisau and Kapuas Regencies, Central Kalimantan (Kalteng) on an area of 1,000 ha each. Head of Balitbangtan Fadjry Djufry explained that this demonstration is called the Food Estate Central of Excellence or the center of excellence of the introduced technology. 

This demonstration is expected to be a model and study for broad and integrated development, especially in the food estate area of Central Kalimantan. According to him, the technology for rice, especially, has been prepared starting from adaptive varieties of swamplands, supporting technology, infrastructure for rice production, and production management. 

The adaptive varieties used include Inpari 30, Inpari 32 HDB, Inpari 42 GSR and rice hybrids, while the supporting technology is the Integrated Plant Management (PTT) technology for swamp rice called RAISA (Super Actual Intensive Swamp) technology. 

Head of the Center for Food Crops Research and Development, Dr. Priatna Sasmita, added that the varieties used were varieties that had been studied for their adaptability in swamps. Furthermore, Sasmita also stated that the demonstration farm uses SS (Stock Seed = Principal Seed) class seed. It aims to harvest the best varieties and use them as seeds for extensive development in food estate areas. 

According to Sasmita, RAISA is an integrated crop management (PTT) of swamp rice which the technological components were assembled by Balitbangtan and includes adaptive varieties, the use of ameliorase (soil improvement) in the form of 1-2 tons/ha of dolomite, application of biofertilizers in the form of Agrimeth which is given as seed treatment and application of Biotara on land, planting methods according to the recommendations (Tabela or Legowo 2:1), regulating micro water systems, fertilizing according to recommendations based on PUTR (Swamp Soil Test Equipment), integrated pest control, and the use of agricultural machinery. 

The Demfarm Food Estate Central of Excellence in Pulang Pisau, located in Blantisiam Village, Pandih Batu District, shows the success of the introduced technology. Plant Destruction Organism Observer Officer (POPT) in Blantisiam Village, Pandih Batu District, Edi Subaedi said that the average harvest of cooperating farmers in Blantisiam was very satisfactory at 5.5-5.6 tons GKG/ha, higher than the yield of previous season. 

The Potential of Swamplands as Productive Rice Fields 

Swamplands have the potential to be used as productive rice fields because they contain more water and last longer than other types of land. So, if the dry season comes, when other lands are dry, the rice fields in the swamplands are still watered for crop development. 

To achieve food self-sufficiency and Indonesia’s target as the world’s food barn by 2045, swamplands can be optimally utilized as an asset to reach the target. For this reason, in 2020 BBSDLP has carried out research on the identification and characterization of swamplands which will produce a map of the distribution of swamps with a scale of 1:50,000 throughout Indonesia. 

The map is needed to support the development areas for agricultural commodities so that the direction of the development and management can be carried out in a precise and directed way. 

The framing of the map is carried out on a scale of 1: 50.000 with landform and hydrological approach to distinguish the tidal swamp and inland swamp as well as the types of overflow with its inundation. The data used are maps which were compiled by BBSLDP, such as the Soil Map with 1: 50,000 scale, Peatland Map with 1: 50,000 scale, spatial data, such as National DEM (DEMNAS) data from BIG, medium resolution images (Landsat), high resolution (SPOT), and other supporting data. 

Swamplands are very potential for food crop farming. With the map, hopefully the utilization of swamplands will be more optimal so that the agricultural sector in the future will be more advanced.