Tidal Swamp Land Research Articles

The Influence of Various Biostimulant Formulas Supplemented with Microbes and Their Application Frequency on Corn Productivity in Tidal Swamplands

Corn is the second most important food commodity in Indonesia. However, its production is lower than the demand. This problem can be overcome using suboptimal land, such as tidal swampland, with its naturally low productivity. The soil quality in such areas can be improved by applying biostimulant. Therefore, this study aims to examine various biostimulant formulas supplemented with microbes and their application frequency on corn productivity in tidal swamplands. It was conducted on a pot experiment using a completely randomized block design with three replications. The treatments were six formulas of biostimulant, each with three application frequencies. The biostimulant materials included rice husk ash, golden apple snail extract, and microbes serving as P-solubilizers, N2-fixers, and IAA phytohormone. The results revealed that biostimulant formulas can increase the production of corn. The B3 formula, followed by the B4 and B5 formula, led to superior grain yields compared to the other treatments. In comparison, the most effective application frequency was observed with four times application (D2) followed by five times application (D3) as the next best option. These biostimulant formulas need to be tested in the field to know their effectiveness in tidal swamplands. Keywords: corn productivity, biostimulant formulas, tidal swamplands, microbial supplements

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.

Assessing the productive potential of high-yielding rice varieties on acid sulfate soils in the tidal swampland of Central Kalimantan

Abstract Tidal swampland holds significant agricultural potential including cultivating rice. Farmers in these regions typically cultivate local rice varieties. Breeding rice techniques have led to the development of superior rice well-suited to thrive in tidal swamplands. This research was conducted on acid sulfate soil within a tidal swampland located in Terusan Karya Village, Kapuas Regency, Central Kalimantan, during the 2021 dry season. The study employed a completely randomized block design with two replications. The experimental treatments comprised nine high-yielding rice varieties: Inpari IR Nutri Zinc, Cakrabuana Agritan, Inpari 3, Inpari 32, Inpari 42, Inpari 47, Inpara 2, Inpara 8, and Inpara 10. The parameters were observed, including plant height, panicle number per hill, panicle length, and grain yield. The high-yielding varieties of rice planted in acid sulfate tidal swamplands exhibit varying growth and yield performances. Grain yields of rice ranged from 5.45 to 7.30 t ha−1 of dry-milled grain. The highest grain yield was shown by Inpari 3 (7.30 t ha−1) and Inpari 32 (7.04 t ha−1). High heritability values are indicated by the traits of dry harvest and milled grains, while wide variability is shown by characters such as plant height, panicle length, grain dry harvest, and dry milled.

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.

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.

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.

Kemasaman Tanah dan Sebaran Senyawa Pirit pada Berbagai Kedalaman Tanah Pasang Surut

Soil acidity (pH) is the main obstacle in tidal swampland. The high soil acidity (pH < 4.0) causes an increase in the solubility of iron (Fe). The high soil acidity affects the balance of chemical reactions in the soil and the availability of nutrients in the soil. The purpose of this study was to determine soil acidity (pH), redox potential (Eh), and soluble Fe at at varying soil depths with different pyrite locations in tidal swampland. This study used a nested design and studied the following factors: 1) Depth of pyrite 0-50 cm layer (actual acid sulfate soil) and 50-100 cm layer (potential acid sulfate soil). 2) Soil depth includes 0-25 cm, 25-50 cm, 50-75 cm, and 75-100 cm. Soil samples were taken at the depth where pyrite was detected, with 3 replicates at each soil depth. This resulted in a total of 24 experimental units. The depth of the nested soil coincided with the depth of the pyrite. The study analyzed the acidity of acid sulphate soil, redox potential, and dissolved Fe at pyrite locations within soil depths of 0-100 cm and 0-25 cm, 25-50 cm, 50-75 cm, and 75-100 cm. The results indicate that there was no significant difference in the measurements between the various soil depths of 0-50 cm and 50-100 cm.

Rapid determination of site-specific N, P, and K management for rice in a tidal swampland

Rapid determination of site-specific N, P, and K management for rice in a tidal swampland

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.

Characteristics and potential of tidal swampland to support the lowland rice development: a case study in Maliku Sub-District, Pulang Pisau Regency, Central Kalimantan Province

Tidal swampland is an agroecosystem with distinct characteristics. Studying on this land was very important to support national food security. This study aims to identify the soil characteristics and the potential of tidal rice fields in the Maliku Sub-District, Pulang Pisau Regency, Central Kalimantan Province, Indonesia. Four representative soil profiles were characterized in the field and laboratory to determine the soil’s chemical, physical, and mineralogical properties. The results showed that these soils were generally fine textured, had very acid to acid reaction (soil pH 3.2-4.7), moderate to high C-organic (2-6%), varied potential P2O5 (22-289 mg/100g), low potential K2O (11-17 mg/100g), varied available P2O5 (8.6-56.1 mg/kg), very low exchangeable Ca (<2 cmolc/kg), varied exchangeable Mg (0.6-3.0 cmolc/kg), moderate soil CEC (18-22 cmolc/kg), very low base saturation (<20%), and shallow to very deep (35 - >100 cm) of pyrite depth. The sand fraction mineral is mainly composed of quartz and rock fragments, while the clay fraction is dominated by kaolinite. The lands are marginally suitable for tidal rice fields with the limiting factor being very acid soil reaction and shallow pyrite depth. The application of balanced fertilization, liming, organic matter, minimum tillage, and micro-water control can increase land productivity.

Strategic, Economic, and Potency Assessment of Sorghum (Sorghum bicolor L. Moench) Development in the Tidal Swamplands of Central Kalimantan, Indonesia

The potency and challenges of sorghum development in tidal swamplands in Indonesia have yet to be well studied. Thus, our study is the first to evaluate the land suitability, economic performance, and strategies for developing sorghum in the tidal swamplands in Central Kalimantan. We use the land suitability evaluation method, a gross margin and profit analysis, a break-even analysis, and a competitive analysis as the methods for assessing the potency and utilization of sorghum in this study. As a tool for decision-making, SWOT was also used, followed by a quantitative strategic planning matrix (QSPM) analysis. The results show that 578,511 ha of arable land is suitable for sorghum development. Economically, sorghum farming can generate IDR 12,894,000 per ha with a revenue-cost ratio of 1.72; the break-even price would be IDR 2447 per kg, around 42% lower than the current market price. Sorghum is also more competitive than cassava (Q = 0.76), sweet potato (Q = 0.58), and soybeans (Q = 0.61) and less competitive than maize (Q = 1.33). Based on the QSPM analysis, five alternative strategies were obtained for developing sorghum in tidal swamplands: (1) optimization of productivity; (2) improvement in the quality of human resources for farmers; (3) facilitation of partnership cooperation; (4) application of site-specific technology; and (5) optimization of waste utilization. These strategies show that the expansion of sorghum planting has potential in the tidal swamplands and economic value for the community.

Adaptation and farmer’s preferences on rice and steamed rice quality of several varieties in Tidal Swampland (case study in Sei Jangkit Village, Central Kalimantan)

The tidal swampland has the potential as a production source and a rice barn, but some obstacles are high acidity and toxic elements resulting in low rice yields. To increase productivity, adaptive and tolerant superior rice varieties are needed. This study aims to obtain adaptive and tolerant rice varieties in the tidal swampland, Sei Jangkit village in Central Kalimantan. The activity was carried out from September 2021 to April 2022. The varieties planted, namely, Inpara-2, Inpari-32, Inpari Nutrizinc, and Baroma. They covered an area of 4 ha and involved eight cooperative farmers. The technology applied in farming is tidal management, which includes water management, ameliorant applicant, balanced fertilization, and control of pests and diseases. The results showed that Inpara-2 gave the highest grain yield (5.12 t/ha), Inpari-32 gave 4.48 t/ha, Inpari Nutrizinc 4.58 t/ha, and Baroma 4.98 t/ha. Farming analysis using the B/C ratio of the varieties planted ranges from 1.28 – 1.57, with Inpara-2 giving the highest B/C ratio (1.57). The Baroma and Inpari-32 varieties are preferred over other types. These two varieties are close to the rice quality of the local variety based on farmers’ preferences.

Feasibility of farming and farmer’s perceptions of introduced technology of rice cultivation on tidal swampland

Tidal swampland has great potential for increasing rice production through the application of introduced technology of rice cultivation. In 2021, research has been conducted at Terusan Karya village, Bataguh district, Kapuas regency, Central Kalimantan to obtain information on the feasibility of farming and farmer’s perceptions as well as extension workers on the introduced technology of rice cultivation on tidal swampland. The survey was conducted on 10 farmers who were purposively selected, while 11 extension workers and 10 farmers who were not implementing introduced technology were randomly selected as comparisons. The introduced technology includes water management, land preparation, amelioration and fertilization, adaptive varieties, and management of plant-disturbing organisms. Data were collected through interviews with farmers using a structured questionnaire. These data include inputs and outputs of rice farming and perceptions of farmers and extension workers on the introduced technology. The data were analyzed using the balance of costs and revenues. The results showed that the introduced technology increased rice production by 27.79% compared to farmer technology. The introduced technology is profitable and feasible to be developed on a large scale with Marginal Benefit Cost Ratio (MBCR) value >2. The perception of farmers and extension workers is positive towards the introduced technology.

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.

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.

Optimizing the use of submergence and drought tolerant rice varieties to reduce the impact of climate change on swampland

The swamplands are one among the possibe suboptimal land for agriculture. The land consists of tidal swamplands and freshwater land that are wide obstainable in Indonesia. The hydrotopography of tidal swampland is powerfully influenced by tide and neap tide of water, whereas in freshwater land it’s for the most part determined by precipitation. Drought, flooding or deep inundation, and shifts in rainfall patterns as a result of extreme temperature change have an impact on agriculture in decreasing food crop production, significantly for rice in swamplands. One strategy in anticipating the impact of climate change in agriculture, particularly food crops (rice) is to use submergence and drought tolerant varieties still as early maturing rice varieties. Rice varieties tolerant of submergence in swamplands like Inpara 3, Inpara 4, Inpara 5, Inpari 29, and Inpari 30 Ciherang sub1. Whereas drought tolerant varieties such as Inpari 18, Inpari 19, Inpari 20, Inpago 4, Inpago 5, Inpago 6, Inpago-8, and Inpago Lipigo-4. In addition to avoiding drought, early-maturing aged rice varieties such as Hipa 6 Jete, Inpari Si Denuk are often used, Inpari-34 Salin Agritan, Cakra Buana Agritan, Inpari 12 and Inpari 13. The purpose of this paper is to explain how planting submergence and drought-tolerant rice varieties can reduce the effects of climate change on swamp agriculture. It is expected to significantly reduce the effects of climate change for agriculture in swamplands by treating submergence and drought tolerance and early maturing varieties.

Financial feasibility of introduced rice cultivation technology on tidal type B (case of Belanti Siam Village, Pandih Batu District, Pulang Pisau Regency)

The Food Estate program in the tidal swampland of Central Kalimantan was implemented to anticipate the food crisis in Indonesia. To obtain information on the financial feasibility of introduced rice cultivation technology on tidal type B, dissemination was carried out in Belanti Siam Village, Pandih Batu District, Pulang Pisau Regency, Central Kalimantan Province, covering an area of 12 hectares in dry season 2021. The introduced rice cultivation technology package which called Panca Kelola consists of water management, land preparation, amelioration and fertilization, adaptive varieties, and management of plant-disturbing organisms. The results of the dissemination showed that the introduced cultivation technology increased the production of high yield inbred rice by 39.20% (1,044.3 kg ha−1) and 48.5% (1,782.6 kg ha−1) of high yield hybrid rice compared to farmer’s technology. Economically, rice cultivation technology using hybrid rice varieties with transplanting systems and inbred rice varieties with direct seed planting systems were profitable and efficient. Rice cultivation technology using hybrid rice varieties with transplanting systems can be developed on a wide scale. Farmer’s perception of introduced rice cultivation technology was positive.

Pemberdayaan Lahan dan Potensi Pertanian di Desa Batuah, Kecamatan Basarang, Kabupaten Kapuas, Kalimantan Tengah

Since 2021, the government has been developing a food estate program at the Desa Batuah, clearing many hectares of rice fields. The problems faced by the community are frequent flooding in the planting area, low pH, and attack of the plant by pests, disease, and weeds that reduce agricultural production. The purpose of community service in this activity is the Batuah Village community and Real Work Lecture-Nationality students who at that time served in Batuah Village were able to explain land empowerment and village agricultural potential and were skilled in carrying out land empowerment, overcoming the problem of nuisance organisms plants and recognize the agricultural potential in the village and then maximize its potential. Empowerment of agricultural land in Batuah Village needs to pay attention to the keys to successful management of tidal swamp land for sustainable agriculture, such as Water Management, Land arrangement, Adaptive and prospective commodity selection, and application of suitable cultivation technology. Few farmers (10%) still need to apply technology to overcome agricultural problems in Batuah Village. The community recognizes the superior potential plant of Batuah Village, such as rimbang Dayak (hairy-fruited eggplant, Solanum lasiocarpum), celery, and bamboo, but this potential has yet to be maximized. Rimbang still needs to be widely used as processed food and mostly only as vegetables for the community. The team and Real Work Lecture-Nationality students succeeded in maximizing the potential of rimbang by processing rimbang into syrup and jam to increase the economic income of the Batuah village community.

Strategy of Rice Productivity Increment Through Agronomical Treatment at Two Flooding Types of Tidal Swampland

The research objective is to increase rice productivity using a ratoon system through N fertilizer and growth regulator treatments at two flooding types of tidal swampland. It was conducted from February to August 2020. The experiment design used in this research is Split Plot Design with three replications. The main plot is N fertilizer and rice variety (NV) which consisted of N1V1= N fertilizing, 1/3 dose during planting + 1/3 dose at primordia phase + 1/3 dosis at harvest for Inpari 30 variety; N1V2= N fertilizing, 1/3 dose during planting + 1/3 dose at primordia phase + 1/3 dose at harvest for Hipa 5 Ceva variety; N2V1= N fertilizing, 1/3 dose during planting + 1/3 dose at primordia phase + 1/6 dose at harvest +1/6 dose at 21 days after harvest for Inpari 30 variety; N2V2= N fertilizing, 1/3 dose during planting + 1/3 dose at primordia phase + 1/6 dose at harvest +1/6 dose at 21 days after harvest for Hipa 5 Ceva variety. The subplot is the application of growth regulator GA3 (G) consisting of G0 = without application of GA3; G1 = application of GA3 once in 7 days; G2 = application of GA3 once in 14 days. The research results showed that N fertilizing, 1/3 dose during planting + 1/3 dose at primordia phase + 1/3 dosis at harvest and application of growth regulator GA3 60 ppm with interval of once in 7 days to ratoon rice is capable to increase rice productivity using ratoon rice system at B and C flooding types at tidal swampland. How to Cite: Gribaldi, Nurlaili, Novriani, S. Diana, N. Marlina, 2023. "Strategy of Rice Productivity Increment Through Agronomical Treatment at Two Flooding Types of Tidal Swampland." Journal of Agriculture and Crops, vol. 9, pp. 199-204.

APPLICATION OF THE PENMAN-MONTEITH METHOD TO DETERMINE THE CROP WATER REQUIREMENTS

Agricultural production is critical to meeting Indonesia's food demands. The water catchment area of Parit Keladi 1, located in Desa Parit Keladi, Kecamatan Sungai Kakap, Kabupaten Kubu Raya, Provinsi Kalimantan Barat, includes tidal swamp land that has a variety of plants. The Cropwat 8.0 Software will be used in this research to assess crop water needs. This research employs primary and secondary data, including soil samples, field cropping patterns, and plant hydration levels.The type of clay soil was silty, the field cropping pattern at the study site was paddy, and the height of the water puddle on paddy was 3 mm/day/ha, according to the findings of primary data analysis on soil sampling. The maximum water need for paddy was 5.90 mm/day/ha in March period 1, while the lowest water requirement was 0 mm/day/ha in October period 1. The maximum water need for citrus was 2.62 mm/day/ha in August for period 3, while the lowest water requirement was 0 mm/day/ha from October to December and May to June for period 1. In September Period 3, the crop water required in the Cropwat 8.0 Software was 32.2 mm/day/ha for ten days; however, the water level in the field was 3 mm/ha for one day in late September. Thus, the estimate of water demands for rice plants using the Cropwat 8.0 Program is valid.