Tidal Swamp Research Articles

Determinan Keputusan Petani Mengelola Usahatani Padi Di Lahan Suboptimal

The conversion of paddy fields seriously impacts rice availability for national food reserves, so the government is implementing a sub-optimal land extension program. Indonesia has suboptimal land that has the potential to become a national rice barn if appropriately managed. The types of suboptimal land most widely used in rice cultivation are lowland and tidal swamps, where the community can work. This research analyzes the determinants of rice farmers' decisions in managing suboptimal land. This research was conducted in West Tanjung Jabung Regency, Jambi Province, with a sample of 90 rice farmers. Data were analyzed using the multinomial logistic regression method. The determining factors are seen from the demographic and economic aspects. The research results show that factors that significantly influence farmers' decisions to choose tidal land from the demographic aspect are age and farming experience; from the economic element are the number of family dependents, land ownership status, and non-farming income. The significant determining factors in farmers' decisions to manage lowland swamp land from the demographic aspect are age and farming experience, and from the economic element are the number of family dependents and non-farming income. From the research, recommendations that can maximize the use of suboptimal land are increasing promotion and education to the community about rice cultivation on suboptimal land, providing easy access for farmers to rent land, and it is hoped that farmers will continue to have non-farming income to balance household needs and procurement of capital and farming input.

Analisis Sistem Jaringan Tata Air Pada Lahan Rawa Pasang Surut, Desa Telang Karya, P87S, Banyuasin, Sumatera Selatan

The world's growing population is increasing the need for land, prompting the conversion of productive agricultural land into non-agricultural purposes. This has led to a shift in agricultural development to sub-optimal lands, such as tidal swamplands. However, several problems arise along the way, including water management. A good water management network is necessary for supporting efficient water use. This study aims to analyze the water system network on tidal swamps to support agricultural activities. The survey and field observation methods were used to collect data. The results showed that the water system in Telang Karya Village, P87S, Banyuasin, South Sumatra, experienced sedimentation in the tertiary channel. In channel 3, the thickness of sediment reached 72 cm, resulting in silting, which reduces water discharge. Field observations revealed that sedimentation occurs due to the channels being overgrown by wild plants. This hampers the water flow, causing it to slow down or even stop. In some tertiary channels, the watergate operation needs to be carried out optimally. Maintaining the ideal conditions of tertiary channels is crucial, and watergate operations should be performed based on the needs of the plants.

Performance test and economic analysis of paddy direct seed planter modified pulled by tractor (amator) in tidal swamp, South Sumatra

Abstract Lack of labor is another obstacle to the characteristics of the tidal swamp land itself so that the use of agricultural equipment and machinery such as Amator can be used as solution. This paper aims to analyze the use of the amator in terms of technical and economic aspects of the equipment so that it is known whether it is efficient and profitable for farmers. Data collection was carried out through observation of equipment performance tests in the field and key informant interviews. This research was carried out in Sri Katon Village, Air Salek District, Banyuasin Regency. The data observed are technical performance including work capacity and work efficiency, as well as economic analysis in the form of basic costs and break-even point of using equipment. The results of the performance test show that the amator has a high efficiency (87.52%) with an effective working capacity value of 0.6244 ha hr−1 (1.6012 hr ha−1). The basic cost incurred for the use of the amator is IDR 193.145 ha−1 with a BEP of 16,8 ha yr−1. The use of amator with seeds only 35 kg ha−1 can save planting costs of IDR 200,000 ha−1 compared to the farmer practice.

Genetic variability and relationship of agronomic characters of soybean lines in tidal swamp land

Abstract Genetic variability and the relationship between agronomic characters have an important role in the development of high-yielding soybean varieties. The aim of the research was to study the genetic diversity and the closeness of the relationship among the agronomic characters of soybean lines in tidal swamp land. The results showed that broad genetic variability was found in the number of branches and seed yield, while the other characters had narrow genetic variability. Individuals in the family are relatively evenly distributed. Based on the PCA biplot, the contribution of agronomic characters was in the similar direction as seed yield, except for maturity. However, there were no characters that are significantly correlated with seed yield. Significant phenotypic correlations were obtained among the number of filled pods, plant height, the number of branches, and the number of reproductive nodes. Almost all of the high agronomic characters belong to the Dh/Arg progenies. The highest seed yields were obtained by Dw/Arg-7 and Dw/Arg-12, namely 2.49 and 2.41 t/ha, respectively. The lines with high seed yield potential were also shown by the Gjs/Arg and Sh/Arg progenies. Dw/Arg-7 and Dw/Arg-12 can be assessed in plant breeding process to obtain high yielding soybean varieties adaptive to tidal swamp areas.

Characteristics and potential of tidal swamplands for sorghum (Sorghum bicolor (L.) Moench) cultivation

Abstract The characterization and potential of tidal swamps as a source of sorghum crop production (Sorghum Bicolor L. Moech), is the first research conducted in tidal lands, considering that so far sorghum has been widely planted in dry land. Aims to identify the biophysical character of the land, and multiply the potential, and technology of sorghum cultivation in tidal lands. Conducted in Kapuas Regency, Central Kalimantan, from August 2022 - April 2023. Land suitability analysis refers to 1:250,000 scale maps, 1:50,000 scale soil type maps, and soil analysis as the basis for determining technological inputs for successful site-specific sorghum cultivation. The results showed the biophysical character of tidal land with pH <5, has low nutrient content, imperfect water management, and proven to have good potential for sorghum growth. The application of dolomite as much as 1000 kg/ha and manure 5000 kg/ha and 200 kg/ha urea, 100 kg/ha SP-36, and 50 kg/ha KCL according to the results of soil analysis, proved that sorghum can produce 3.07 t/ha in tidal land, and almost the same as production in a dry land.

Enhancing Rice Productivity and Ensuring Food Security in Indonesia Through The Adoption of Innovative Technologies in Tidal Swamp Rice Farming

The expansion of rice cultivation areas in tidal swamp lands is crucial for Indonesia to increase rice production in order to meet the rising food demand in line with population growth. The purpose of this study is to comprehensively explore and assess innovative technologies that can be developed for rice cultivation in tidal swamp lands. The research was conducted using ScienceDirect (Core Collection) with keywords "Tidal Rice Farming," "Rice Productivity," "Technology," and "Food Security in Indonesia," and Google Scholar with keywords "Rice Production," "Tidal Swamp Rice," and "Indonesia," following the guidelines from PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The research includes peer-reviewed studies published between 2014 and 2024, focusing on the recent technology of rice farming in tidal swamp fields. The research result show Tidal swamp land in Indonesia, covering 8.92 million ha with mineral soil 7.56 million ha and peat soil 1.36 million ha, mainly used for rice farming 2.8 million ha. The current rice productivity ranges between 4-5 million tons of unhulled rice per year. This finding concludes that the adoption of innovative technologies can be applied to increase rice productivity in tidal swamps, which holds great potential for enhancing food security in Indonesia. The study also highlights the importance of additional research to address challenges such as soil salinity, water availability, accessibility, and the adoption of these technologies across different tidal swamp land conditions.

Responses of shallot to ameliorant and actinobacteria applications in water-saturated system on tidal land

Tidal areas are believed as future land for many commodities in Indonesia. Here, shallot growing was evaluated on tidal land supplemented with soil conditioners. The research aimed to evaluate the adaptive response of shallot varieties for growing on tidal land with a water-saturated system indicating Fe and Al stress by applying soil ameliorant and actinobacterial. The study used a completely randomized factorial design with three replications. The first factor was shallot variety (Bima Brebes, Batu Ijo, and SS Sakato) and the second factor was soil conditioners (no ameliorant, actinobacteria, ameliorant+actinobacteria, and actinobacteria+ameliorant+dolomite). Bima Brebes and Batu Ijo cultivars had the highest growth percentage, age at shoot emergence, plant height, and number of leaves, while the SS Sakato variety had the slowest growth. Shallot production variable had a significant interaction with soil conditioners. Bima Brebes variety demonstrated high suitability for a water-saturated system in tidal land, and actinobacteria+ameliorant+dolomite was a more promising conditioner than other treatments. Keywords: pyrite, saturated soil culture, tidal swamps, growth, yield, marginal land.

Enhancing Seedling Performance Direct Seeded Rice Under Anaerobic Germination Condition by Seed Invigoration

In an effort to address labor scarcity and enhance the cropping index in tidal swamp areas, farmers utilize direct seeding techniques. However, flooded conditions due to tides and ebb can hinder seed germination. This study aimed to obtain the best invigoration treatment for improving seedling establishment and growth in South Sumatra's tidal swamp hotspots. In the first part of the study, 19 different seed treatments were tested on the swamp rice variety, Inpara 9, in a greenhouse. These treatments included hardening, priming, thermal treatment, and controls. Soluble sugar content and α-amylase activities of treated seeds were analyzed in the lab. The results showed that the invigorated seeds outperformed the control group in terms of seedling growth and development when they were planted directly in the ground under both anaerobic germination (AG) and anaerobic germination with extra FeSO4 added to the soil (AG+Fe) conditions. All treated seeds also exhibited higher soluble sugar and α-amylase activities. A follow-up experiment in a hotspot area assessed the effectiveness of the top nine seed treatments from the first experiment under AG conditions. The flooded level was managed at around 10 cm during the experiment and Inpara-9 was the variety planted. All invigorated seeds exhibited superior seedling establishment and growth compared to the control on in-situ swampy land. Hardening using Trichoderma yielded the highest seedling establishment and performance, indicated by greater root and shoot dry weight than other treatments, followed by hardening with Methylobacterium td-J7 and Methylobacterium td-tpb3.

KARAKTERISASI SELULASE TERMOSTABIL ASAL ISOLAT BAKTERI TANAH PERTANIAN PASANG SURUT

Cellulase is an enzyme that can break up β - (1→4) glycosidic bonds of cellulose. Generally, cellulases are classified into three major groups, i.e., endoglucanase (EC 3.2.1.4), exoglucanase (EC 3.2.1 .91), and β glucosidase (EC 3.2.1.21). Meanwhile, five isolates of tidal swamp soil have been isolated; thus, in this research step, we are acquainted with cellulase activity and the characterization of cellulase enzymes on various temperatures, pH, and specific substrates. The activity of an enzyme was measured using the modified Miller and Bradford methods to detect the specific characteristics of the isolate. The results showed that five isolates namely ATP-1 BKP-5, HAMML-2, PKL-2, and SPBKK-3 have activities 0.025 nKat.ml-1, 0.032 nKat.ml-1, 0.296 nKat.ml-1, 0.114 nKat.ml-1, and 0.087 nKat.ml-1, respectively. Furthermore, cellulase from isolates ATP 1, BKP-5, and PKL 2 have an optimum activity at pH 7,0; 50 oC. The isolate HAMML-2 has an optimum activity at pH 5,0; 60 oC. SPBK 3 has an optimum activity at pH 5,0; 50 oC. All of those isolates can degrade CMC, Avicell, and Whatman paper No.1 and retain the activity relative to the temperatures 50 and 60 0C as the characteristics of the thermostable enzyme.

Utilizing Rice Hull Ash and Biomass as Ameliorants Enhanced Soybean Yield and Nutrient Uptake in Tidal Swamps Under Saturated Soil Culture

Saturated soil culture (SSC) is a promising technology for cultivating soybeans in acidic soil in tidal swamps. The objectives of this study were to measure nutrient uptake in the soybean plant using a saturated soil culture technique and to assess the impact of ameliorant addition in the form of rice biomass and rice hull on soybean yield. Two factors, rice biomass, and rice hull ash, were used in a split plot factorial design to set up the experiment. Four levels in the main factor included without biomass immersion, one immersion of short (3 cm above the root) rice stubble, one immersion of regular (panicle harvested only) rice straw, and two immersions of regular rice straw cut in the soil. The four levels in the subfactor were 0 t ha-1, 0.25 t ha-1, 0.50 t ha-1, and 0.75 t ha-1 of rice hull ash doses. Ameliorant in the form of biomass and rice husk increases soil quality in tidal swamps by enhancing pH, soil nutrients (N, P, K, S), CEC, cations, and base saturation, also reducing toxic compounds and improving soil texture. Application of ameliorant also increases soybean nutrient uptake and eventually increases the productivity of soybeans in tidal swamp acid soil. The best treatment of the first and second factors was one immersion of biomass with a regular cut of rice straw and 0.5 t ha-1 ash rice hull ash addition to the tidal swamp soil, respectively.

Evaluasi Kinerja Saluran Irigasi Daerah Irigasi Rawa Kumpeh Desa Maju Jaya Kabupaten Muaro Jambi

The Rawa Kumpeh Irrigation Area is one of the swamp irrigation areas that is still actively operating in Muaro Jambi Regency. In the management of swamp irrigation areas in this area, namely the performance of the swamp irrigation area itself, which includes the availability of water obtained from the tides of the Kumpeh River as well as the need for irrigation water for food crops, namely rice and secondary crops developed in the swamp area. Apart from that, the main thing about Tidal Swamp Irrigation is water management with a Water Gate Operation System. The aim of this research is to determine the performance conditions of Swamp Irrigation Areas, especially DIR. Kumpeh Swamp which can provide input in managing the swamp irrigation network. The data collection methodology was carried out by means of interviews, literature studies and field surveys. The results of this research can be concluded that the network performance value at the research location is 70.00% - 90.00% for performance. Condition is in the good category (functions well, no significant damage was found). Includes Primary, Secondary SK 1, Channel Types. SK.2, SK.3, SK.4, and SK.5 Block E, the network performance value at the research location is 55.00 % - 69.00 % for performance Condition in the Medium Category (functional, found there is damage but can resolved and put into operation) Includes Secondary Block E SK.4, while for the buildings at the research location, there are 3 (three) sluice gates with sliding doors in fairly good condition with the building performance assessment results averaging 82.81 % where the results of the performance value are included in good performance (70 - 90%). The performance value of the canals and buildings at the research location can also be concluded as the magnitude of the benefit value of the canals and buildings, in relation to the area of agricultural services that utilize these canals and buildings to irrigate agricultural land.

Pengaruh pemupukan P dan populasi jagung dengan tumpang sari kedelai pada budidaya jenuh air di lahan pasang surut

Soybean and corn are the main food crops in Indonesia after rice. Currently to fill the needs of national soybeans and corn obtained through imports. That was due to the low productivity of soybeasn and corn in Indonesia compared to other countries like as the United States and China. Iimproving the productivity of corn and soybean is by regulating plant population and fertilizing. The purpose of this research was to determine the effect of P fertilizing and corn population on soybean and corn intercropping in tidal swamps. This research was in March to August 2019 in Karyabakti, Rantau Rasau District, Tanjung Jabung Timur Regency, Jambi Province. The tidal swamps type used was type B. The study was conducted using two factors i.e P fertilization (0 kg P2O5 ha-1, 46 kg P2O5 ha-1, 92 kg P2O5 ha-1, 138 kg P2O5 ha-1) and population maize (50,000, 63,000 and 73,000 plants ha-1). The intercropping system showed the highest results in a population of 63,000 maize ha-1 plants with a fertilizer dosage of P 46 kg P2O5 ha-1. Land equality ratio highest 2.3 showed that intercropping systems were 130% more effective than monoculture planting.

Properties of soils on fluvio-marin landform and their land management strategy for paddy field in Bataguh swampy area, Kapuas Regency, Central Kalimantan Province, Indonesia

Tidal swamp land has strategic and prospective value in sustaining national food resiliency and reserves. This land has the potential for the development of commodity paddy fields. However, this type of tidal swamp has a unique character and influences land management. This research aims to determine soil properties on landform fluvio-marine and its potential for developing lowland rice in Bataguh District, Kapuas Regency, Central Kalimantan. A total of 4 representative soil profiles were identified and characterized in the field and laboratory. Research results show that the lands under study have fine texture. Soils in the surface layer are classified as very acidic to acidic (soil pH 3.3-4.7), has very high organic C levels (5.46-9.37%), potential P moderate (21-40 mg.100g-1), K potential low until moderate (16-21 mg.100g-1), exchangeable Ca low (2.24-3.17 cmolckg-1), exchangeable Mg medium (5.11-8.30 cmolckg-1), soil CEC medium until high (19.63-38.09 cmolckg-1), and base saturation low until high (37-63%). The depth of sulfidic materials or pyrite layer is shallow until deep within 50-85 cm. The sand mineral fraction is dominated by quartz, while the mineral fraction of clay is dominated by kaolinite, followed by vermiculite and illite. The land studied is classified as marginally suitable (S3) for the development of tidal rice fields with a limiting factor for acid to very acid soil reactions (soil pH <5). Balanced fertilization, liming, and micro water management can be done to increase the productivity of this land.

Assessment of some heavy metal content in sediments of a mangrove swamp, niger delta, nigeria using applicable ecological risk indices

Sediments can act as pollutant sinks and a source of pollution in aquatic environments. The surface sediments of the Isaka–Bundu tidal swamp, Niger Delta was assessed for heavy metal content using standard methods and assessment indices. The study was carried out in three stations between January and June 2022. Five heavy metals (lead, copper, cadmium, nickel and zinc) were evaluated while eight assessment indices (Contamination Factor - CF, degree of contamination - DC, Ecological Risk - Er, Potential Ecological Risk - PERI, Pollution Load Index - PLI, Enrichment Factor - EF, Geo-accumulation Index - Igeo and Quantification of Contamination -QoC) were applied. Results showed that cadmium and copper exceeded permissible limits while lead, zinc and nickel were within limits. Stations 1 and 3 recorded significantly higher values indicating anthropogenic influence. The dominant anthropogenic activities observed in the area include maritime and dockyard activities and artisanal crude oil refinery. The assessment indices showed that the sediments were at various levels of heavy metal pollution mainly influenced by copper and cadmium viz: CF: Cu (considerable degree) and Cd (very high degree), DC (very high degree), Er: Cd (high ecological risk) and Cu (very high ecological risk), PERI (significant high ecological risk), PLI (very high level pollution), EF: Pb, Zn, Cu (Station 1) and all Cd (extremely high enrichment), Igeo: Cd (extremely polluted) and QoC: Cu and Cd (anthropogenic source). The sediments were highly polluted with toxic metals, which is detrimental to humans and aquatic biota.Keywords: Heavy metal; Indices; Mangrove; Niger Delta; Sediment.

The Adaptation of Ciherang Rice Variety Roots to Various Levels of Low Nutrient Stress in Tidal Swamp Soils

Rice cultivation in tidal land has many abiotic stresses. One of them is low nutrient stress. This research aims to determine and study the adaptation of rice roots to various levels of low nutrient stress in tidal swamp soil. These research was carried out from September 2016 to May 2017 at the Experimental Garden, Laboratory of Botany and Plant Physiology of Faculty of Agriculture of IBA University in Palembang, South Sumatra Province. These experiment used a Randomized Block Design with three replications and four low nutrient levels. The treatments are: N1 = 40% Fertilization dose (FD, N2 = 50% FD, N3 = 60% FD and N4 = 100% FD. The 100% FD is 300 kg urea. ha-1, 100 kg SP-36.ha-1 and 150 kg KCl.ha-1. These research used Ciherang rice varieties that planted in pots containing 12 kg of tidal swamp soil type B from Bunga Karang Village, Tanjung Lago District, Banyuasin Regency, South Sumatra Province, Indonesia. The results showed that low nutrient stress increased root length, root weight, root length density, root weight density, root weight ratio and number of tillers, but reduced crown weight and panicle weight per clump

Logging Identification and Distribution of Bauxite in the Southwest Ordos Basin

In recent years, with the discovery of oil and gas in the Carboniferous bauxite reservoir in the Ordos basin, the formation and distribution of bauxite and bauxite reservoirs have attracted the attention of oil and gas explorers. Based on the slightly equidistant core testing of minerals and the porosity on the formation and calibration on the logging curves, we established a logging identification method for bauxite in the study area and fitted the formula for calculating the diaspore content and porosity using logging data. By applying this formula and a large amount of logging data, thickness and porosity maps of the Taiyuan formation of bauxite in the southeastern part of the basin were produced. Then, according to the thickness of the earliest deposited Taiyuan formation on the unconformity surface, we analyzed the paleogeomorphology of the bauxite deposition. Finally, a sedimentary facies map of the Taiyuan formation was developed based on the content of sandstone, coal seams, and carbonate rocks contained there. The results show that the diaspore content of bauxite is positively correlated with the natural gamma logging (GR) values. According to the diaspore contents and the GR values, the aluminiferous rocks in the Taiyuan formation can be divided into three categories: ① Bauxite for GR values > 450 API and diaspore content >70%; ② Argillaceous bauxite for GR values = 300–450 API and diaspore content = 25%–70%; and ③ Bauxitic mudstone for GR values = 220–300 API and diaspore content = 0%–25%. Bauxite mainly occurred in the middle and deep lagoon environments in the lower part of the Taiyuan formation. The lagoon is distributed along the paleokarst groove in the NW strike, with a width of approximately 30–40 km and a length of approximately 150–200 km, among which the thickness of pure bauxite is 9 m, argillaceous bauxite 26 m and alumina mudstone 6 m. Bauxite with a high porosity mainly existed in pure bauxite. The lagoon bauxite in the lower part of the Taiyuan formation gradually changes upward into a tidal flat swamp and carbonate platform environment.

The Potential and Prospect of Tidal Swamp Lands for Sustainable Soybean Production

The demand for food, particularly as a source of protein for the majority of Indonesia’s population, has not yet been satisfied by the country’s soybean production. For these reasons, the government works nonstop to intensify and extend soybean production in order to enhance productivity. Indonesia has a sizable amount of tidal marsh area (more than 700 000 ha) that is spread out throughout a number of islands, including Sumatera, Kalimantan, and Papua. The physical and chemical characteristics of the soil, such as water saturation in the root zones, a low pH, and a high Al concentration for soybean growth, are the main limitations of this land. However, the area may produce high soybean productivity (2.0 - 2.5 t/ha) with excellent management techniques. It is already possible to grow soybeans on tidal marsh lands using land and plant management techniques like fertilization, water management, amelioration, and tolerance varieties. In order to ensure sustained national soybean production in Indonesia and achieve self-sufficiency, tidal swamp areas have tremendous potential and chances for development.

Thin layer drying model of local rice grain Siam mutiara variety from tidal swamp land in South Kalimantan

As staple food in many countries, rice is one of the most important cultivated plant. Indonesia is the third largest rice producer in the world with annual production of 54,65 million tons. South Kalimantan province has 191,740 ha of tidal swamp land, which equivalent to 30% of its total area. Paddy rice variety planted in this region is dominated by local varieties, such as Siam Mutiara. Local farmers prefer this variety due to its high demand and high selling price than other local rice varieties. This variety produces soft textured rice which is preferred by the people of South Kalimantan. In addition to the taste and texture, physical aspects such as wholeness of the grain is also important for consumers, and this aspect is affected by post-harvest processed such as drying. In this study, drying characteristics of Siam Mutiara variety was studied. Samples of Siam Mutiara from Jelapat 1 village, Barito Kuala district were dried using a Fixed Bed Dryer at three temperatures (40, 50, and 60°C) and an airflow rate of 1 m/s. The samples were dried in five trays made of PVC pipes (5” diameter and 1” length) which arranged vertically. The first four trays were used to dry paddy rice sample with a layer of 1 cm thick, and the lowest tray were used to dry the sample in a single layer grain (with average thickness of grain width 1,66 mm). The temperature and humidity at each tray monitored continuously, and the weight of the sample in each tray was measured every 30 minutes. The results of this study indicate that the temperature and humidity varied among the trays, where the lowest tray had the highest temperature and the lowest air humidity. However, moisture content of the samples in all of the trays are relatively similar for both the top four trays (with total of 4 cm) and the lowest tray (single layer). This result indicates that for Siam Mutiara variety, a total of 4 cm thick layer can still be considered as a thin layer drying. It also found that the effect of drying temperature on drying rate is significant. In addition, the drying characteristic of this rice variety can be best modelled using Page Model.

GRAIN YIELD STABILITY OF SWAMP RICE LINES ACROSS SWAMPLAND AGROECOSYSTEMS IN BENGKULU PROVINCE OF INDONESIA

Multi-environment experiment undertakings in 2020 recognized the stability and adaptability of promising swamp rice genotypes on five types of swampland agroecosystems. Grain yield data recording occurred on 10 swamp rice favorable lines and two check cultivars, transplanted on swamps consisting of alluvial mud, lowland peaty, lowland peat, middle estuarine tidal, and lower estuarine tidal swamp, then subjected to a combined analysis of variance. The AMMI model employed illuminated the effects of environments on a genotype’s grain yield stability across the surroundings. Among the tested conditions, alluvial mud and lowland peat swamps showed as the most predictable environments for rice grain yield evaluation, with the former also representing a rich surrounding, whereas the latter a poor one, despite their provided weak genotype discrimination. Lowland peaty swamp was also a productive environment and conferred strong genotypic discrimination. Both middle and lower estuarine tidal swamps were less fruitful and had rationally durable genotype discrimination. Rice lines UBPR 1, UBPR 8, UPBR 2, and UBPR 4 indicated more desirable than the check cultivars (Inpara 6 and Inpara 4) for grain yield and stability across the test environments. The lines UBPR 3 and UBPR 10 enunciated desirable adaptive performance at the lowland peaty swamp.

Availability and potential for expansion of agricultural land in Indonesia

Land is a critical factor in agriculture, especially in soil-based cultivation. The prevailing problem in agricultural land use that is yet to be solved is the rapid conversion to non-agricultural use, which raised concern for agriculture’s existence in the future. Moreover, the population continues to grow despite the receding agricultural land to produce food. Therefore, research and policies are starting to lean towards optimization of marginal land for agricultural activities. Indonesia still has potential marginal land for agricultural expansion. This paper uses secondary data and former studies to summarize the potential and availability of marginal land for agricultural expansion based on the land categories: forest land, dryland, and wetland (tidal swamp and peat). This paper also discusses the government's extensification program and the results of its implementation. We found that various reports about marginal lands utilization emphasized optimizing the target land with appropriate agricultural technology. The presentation of data obtained through literature studies can strengthen the opinion that the potential availability and potential for expansion of agricultural land in Indonesia is real. This paper is expected to provide a comprehensive reference for all Indonesian regional governments, so stakeholders continue optimizing the potential of existing natural resources.