VARIABILITY OF GROUND WATER TABLE AND SOME SOIL CHEMICAL CARACHTERISTIC ON TERTIARY BLOCK OF TIDAL LOWLAND AGRICULTURE SOUTH SUMATERA INDONESIA

Agriculture and irrigation policies in the tidal wetlands are often too general, thus at the level of farm units they are often inaccurate in term of quality and quantity. The research purpose was to analyze the groundwater levels and to determine the effect of groundwater levels in relation to some soil chemical characters in tidal wetlands P17-5S Mulyasari village Delta Telang II Banyuasin.  Indicators of potential land can be analyzed from parameters of variability of soil acidity, Al and Fe content, organic matter and phosphorus and nitrogen status of the soil. Managed limited area was the smallest unit of water management (tertiary plots). The decision was taken based on the dominant values of the hydro-physical and chemical characters. Input criteria design involved the nature of the soil, land use, and hydrology. The field study and analysis showed dominance in soil physical variability. Around 50% of hydraulic conductivity was classified rapid soil with soil acidity is relatively high, moderate nitrogen, low phosphorus, and moderate potassium. Based on these conditions, cropping pattern applied was rice-corn, rice-water melon, soil fertility can be improved through fertilization of N and P; increasing water gate in the tertiary plots, and the water management aimed to controlled drainag

ANALISA KEBUTUHAN SISTEM MONITORING HIDROLOGI PADA KAWASAN DAERAH ALIRAN SUNGAI MUSI SUMATERA SELATAN

Tujuan penelitian adalah untuk melakukan rasionalisasi jaringan hidrologi pada WS Musi sehingga diperoleh sistem jaringan hidrologi yang efektif, efisien dan dapat mewakili karakteristik suatu DAS, sehingga biaya yang dibutuhkan untuk operasi dan pemeliharaan pos hidrologi dapat ditekan seminimal mungkin. Ada tiga metode analisis yang akan digunakan yaitu: Analisis survei dan pembobotan, untuk rasionalisasi jaringan pos hidrometri; Analisis dengan metode stepwise dan metode Kagan, untuk rasionalisasi jaringan pos curah hujan; dan Analisis regional, untuk rasionalisasi jaringan pos klimatologi. Rasionalisasi jaringan hidrologi dilakukan terhadap pos hujan, klimatologi, dan hidrometri. Hasil analisis terhadap kondisi stasiun curah hujan menunjukkan dari 25 stasiun curah hujan yang ada di WS Musi, hanya 19 stasiun yang memiliki data curah hujan relatif baik, sedangkan data curah hujan pada 9 stasiun yang lain tidak lengkap bahkan tidak ada database sama sekali. Selanjuntya dalam makalah ini akan dihasilkan rekomendasi kebutuhan stasiun curah hujan dan hidrometri yang diperlukan di masing-masing wilayah dan stasiun yang bisa di tutup, untuk menghemat biaya

Pengembangan Irigasi Bawah Tanah Untuk Irigasi Mikro Melalui Metoda Kapilaritas Tanah

Aplikasi irigasi bawah tanah di Indonesia belum begitu berkembangan meskipun system ini memiliki efisiensi pengairan yang tinggi. Penelitian bertujuan untuk memperkenalkan inovasi baru tentang irigasi bawah tanah yang dapat terapkan secara mikro dengan memanfaatkan limbah plastic. Irigasi bawah tanah dibuat dari botol aqua yang dihubungkan dengan sumbu kain. Air akan bergerak secara kapiler membasahi tanah. Hasil uji dirumah kaca menunjukkan bahwa pergerakan air secara kapiler memerlukan waktu 30 menit untuk membasahi tanah hingga diatas kapasitas lapang. Tinggi tanah adalah 10 cm dan diameter pot adalah 10 cm. Sementara itu penguapan air setiap hari adalah 0,4 cm  atau 4 mm. Kalau kebutuhan air tanaman setara 5 mm, maka bila pemberian air di botol setinggi 10 cm, maka interval pengairan adalah setiap 20 hari. Hasil inovasi ini berdampak postif bagi pengembangan irigasi mikro khususnya untuk skala rumah tangga dan rumah kaca. Pemanfaatan limbah plastik botol aqua membei kontribusi positif bagi lingkungan karena mampu mengurangi volume limbah. Selain itu irigasi ini hemat air karena tidak ada air hilang karena perkolasi atau limpasan permukaan.Kata kunci: irigasi bawah tanah, irigasi mikro, limbah botol aqua

Impacts of El Niño Climate Anomaly on Irrigation Scheduling of Maize Crop Using Budget Models under Tropical Climate Conditions

The research aims to calculate the water requirement and irrigation interval of maize crop as well as to design water-efficient irrigation application system. The study was conducted on dry land of Palembang city of South Sumatra. The indicator crop used in this study was maize. Daily climate data were taken from Sultan Mahmud Badarudin and Kenten station. The research applied survey method, laboratory analysis, computer simulation and irrigation design. The calculation of water crop deficiency was done using empirical approach by multiplying the potential evapotranspiration value by crop coefficient. Soil water retention characteristic was recorded based on the calculation of the length of water available to plants. Daily rainfall in the field was recorded as water input other than water from irrigation. The combination of soil, climate and plant physiological properties (Agro-pedo-climatic) will result in a water irrigation system in a region. Water balance analysis was developed by the help of computer model (BUDGET model). The result of computer model analysis shows that maize crop in rainy season does not require irrigation. While for the transition period (March-May), irrigation is required for the flowering phase with a total water requirement of 76.5 mm. During dry season (May-July), irrigation is required with water requirement of 198 mm. Irrigation scheduling is set up 9 times with intervals every 7 days at the beginning of growth and 10 days at the middle and end. While the testing under dry climate conditions (El Niño) using rainfall data in 2015 indicates irrigation should be given since March and during planting period (May-August 2015) the irrigation should be applied 12 times with intervals every 5 days at the initial stage and 10 days during vegetative stage

Changes to Some Physical Properties due to Conversion of Secondary Forest of Peat into Oil Palm Plantation

The purpose of this study was to study how the physical properties of peat change due to the conversion of secondary forest into oil palm plantations.  It was done by comparing the three conversion stages of the secondary forest into shrubs and oil palm plantations.  The study was conducted in Ogan Komering Ilir District, South Sumatera Province, about 100 km south of Palembang, Indonesia from August to December 2016.  Data collection was done randomly at all sites, each of five points for field sampling, observation of soil profile and measurement of hydraulic conductivity and water table depth.  The samples were collected at a depth of 0-30 cm, both for undisturbed cores and bulk samples.  The hydraulic conductivity was measured in the field using the auger holes method.  The peat strength was determined by using the hand operated cone penetrometer.  Data analysis was done descriptively and regression correlation test.  The results showed that conversion of secondary forests into oil palm plantations has led to the decline in the quality of some of the physical properties of peat by decreasing total porosity, water table depth, hydraulic conductivity, organic matter content, moisture content and increasing the bulk density and peat strength

Water Table Fluctuation in Tidal Lowland for Developing Agricultural Water Management Strategies

Water Table Fluctuation in Tidal Lowland for Developing Agricultural Water Management Strategies (MS Imanuddin, E Armanto, RH Susanto and SM Bernas):The research objective is to evaluate the water status in the tertiary block of tidal lowland for developing water management strategies and cropping pattern for food crop agriculture. The research was conducted in tidal lowland reclamation areas of Delta Saleh South Sumatera. The methodology used in this research was survey and monitoring. The result showed that the study area has a potential of acid sulphate soil which is indicated by phyrite layer at 60 cm below the soil surface. Variation of water table was very high in the range of 0-2 cm at rainy season and it was drop up to 90 to 100 cm below soil surface at dry season. This conditions result in the soil oxidation and the pH drop up to 2.5-3.5 (very acid). Analysis of water surplus and deficit during one year period was calculated by surplus excess water under 30 cm (SEW-30) and showed that the area study was experienced water deficit. Analysis of groundwater effect on soil moisture content showed that the critical water level was in 60 cm below soil surface. The soil moisture content at this point in the root zone was dropped into the wilting point level. It means that the water availability for crop water requirement is inadequate. For sustainable agriculture in the area study, the water table should be maintained in 50-60 cm below soil surface. Therefore, the recommendation of water management strategies in the study area is water retention in combination with control drainage system

Land Suitability and Agricultural Technology for Rice Cultivation on Tidal Lowland Reclamation in South Sumatra

Tidal lowland is one of the potential lands for agriculture that is found very widely in coastal areas of South Sumatra. There are about 400,000 hectares (ha) was reclaimed for agriculture purpose. However, in many parts, the rice production is still low (<3 ton/ha), mainly in the high part of hydrotopography class (Type C) that the tidewater could not possibly irrigate the land.  This study aimed to evaluate the level of actual and potential suitability of tidal swamps for rice plants. This research has been carried out in Bandar Jaya Village, Air Sugihan Subdistrict, Ogan Komering Ilir Regency. This research used a survey level method with very detailed (intensive) with a scale of 1:6,000 covering a research area of 16 ha. The results showed that actual suitability for rice plants in the study site is N-n with an area of 5 ha and N-f, n with an area of 11 ha with limiting factors of soil pH and P nutrient. The potential land suitability class for rice plants in the study location is S3-n with an area of 5 ha and S3-f, n with an area of 11 ha. Land quality improvement was done by using the lime application and control water table at a depth of at least 10 cm from the soil surface during rice growth.  Rainwater should be retained in the tertiary block as much as possible to fulfill crop water requirements. Setting the planting time (November-January) and balanced fertilization will be able to increase the land suitability class to S1 (highly suitable)

Conditions of total coliform in the Aur River, Palembang City, South Sumatra, Indonesia

Pathogenic microorganisms present in river water pollution are a serious health risk. Escherichia coli is a pathogen commonly found in water. Escherichia coli is an indicator of water contaminated with feces. These pathogens have an impact on human health. Aur River is one of the tidal rivers in Palembang City. From the observations, many people dispose of domestic waste into river bodies, so the river is at risk of being polluted by pathogenic microorganisms. When it recedes, the water looks pitch black, and when it is high, many people bathe, brush their teeth, and wash their clothes in this river. Thus, this study aimed to monitor water quality, including total coliform, of the Aur River Palembang City. The results of this monitoring can be used as the basis for making a policy and strategy to control the quality of this river water. This study was carried out on the Aur River, which is 2.5 km long. Measurements were made at three stations, namely at the upstream, middle, and downstream. Based on measurements of the pH, BOD, COD, DO, and total coliform concentrations, it is concluded that the Aur River has been polluted because the BOD, COD, DO, and total coliform were above the quality standards. The pH is still at the quality standard