Evaluation of irrigation water requirements and crop yields with different irrigation schedules for paddy fields in ChiaNan irrigated area, Taiwan

2013 ◽  
Vol 12 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Sheng-Feng Kuo
2021 ◽  
Author(s):  
Romeu G. Jorge ◽  
Isabel P. de Lima ◽  
João L.M.P. de Lima

<p>In irrigated agricultural areas, where the availability of water for irrigation does not rely on any water storage, water management requires special attention, in particular under large annual and inter-annual variability in the hydrological regime and the uncertainty of climate change. The inherent increased vulnerability of the agro-ecosystem, makes the monitoring of crop conditions and water requirements a valuable tool for improving water use efficiency and, therefore, crop yields.</p><p>This presentation focus on one such agricultural area, located in the Lis Valley (Centre of Portugal), which is a rather vulnerable area also facing drainage and salinity problems. The study aims at contributing to better characterizing the temporal and spatial distribution of rice water requirements during the growing season. Irrigation water sources are the Lis River and its tributaries, which discharges depend directly from precipitation. The most important problems of water distribution in the Lis Valley irrigation district are water shortage and poor water quality in the dry summer period, aggravated by limitations of the irrigation and drainage systems that date back to the end of the 1950’s.</p><p>We report preliminary results on using remote sensing data to better understand rice cropping local conditions, obtained within project GO Lis (PDR2020-101-030913) and project MEDWATERICE (PRIMA/0006/2018). Rice irrigation is traditionally conducted applying continuous flooding, which requires much more irrigation water than non-ponded crops, and therefore needs special attention. In particular, data obtained from satellite Sentinel-2A land surface imagery are compared with data obtained using an unmanned aerial vehicle (UAV). Data for rice cultivated areas during the 2020 cultivation season, together with weather and crop parameters, are used to calculate biophysical indicators and indices of water stress in the vegetation. Actual crop evapotranspiration was appraised with remote sensing based estimates of the crop coefficient (Kc) and used to assess rice water requirements. Procedures and methodologies to estimate Kc were tested, namely those based on vegetation indices such as the Normalized Difference Vegetation Index (NDVI). Results are discussed bearing in mind the usefulness of the diverse tools, based on different resolution data (Sentinel-2A and UAV), for improving the understanding of the impacts of irrigation practices on crop yield and main challenges of rice production and water management in the Lis Valley irrigation district.</p>


EXTRAPOLASI ◽  
2021 ◽  
Vol 18 (1) ◽  
pp. 25-32
Author(s):  
Hudhiyantoro Hudhiyantoro ◽  
Bayu Aji Dwi Saputro

AbstractBendung Cawak is located in the district of Kepohbaru, Bojonegoro. Bendung Cawak is used for irrigation and water supplies of Kepohbaru, water availability is insufficient, while the amount of land and also residents who need water, so optimization Bendung Cawak is necessary for the water pitcher bendung can be optimized according to the needs.In this study, to maximize the area of land irrigated area to be optimized. In the optimization model used is the optimization of the monthly for 1 year by calculating the area of irrigated land available, land irrigation is met, the greater availability of water and irrigation needs are met. Optimization method used in this calculation is Program Solver.The results obtained by the reliable discharge available in the Cawak dam reservoir are 2.547 m3 / second. The need for irrigation water with the cropping pattern of Palawija-Padi-Padi at the beginning of planting in August I is 0.579 l / sec / ha as a planting plan with the minimum water requirements. As well as optimization, the optimum cropping pattern and initial planting are August I with the Palawija-Padi-Padi planting intensity 291% and with irrigation area MT I 675 ha, MT II 742 ha, MT III 742 ha. AbstrakBendung Cawak terletak di Kecamatan Kepohbaru, Kabupaten Bojonegoro. Layanan Bendung Cawak dipergunakan untuk keperluan irigasi di Daerah Irigasi Cawak Kecamatan Kepohbaru, ketersediaan air yang tidak mencukupi sedangkan banyaknya lahan yang membutuhkan air , sehingga Optimasi Bendung Cawak sangat diperlukan agar air tampungan Bendung dapat dioptimalkan sesuaidengan kebutuhan.Pada studi ini, untuk memaksimalkan luas lahan irigasi dilakukan optimasi luas lahan irigasi . Dalam model optimasi yang digunakan adalah optimasi satu bulanan selama 1 tahun dengan memperhitungkan luas lahan irigasi yang tersedia, luas lahan irigasi yang terpenuhi, besarnya ketersediaan debit air maksimal, dan kebutuhan air irigasi yang dipenuhi. Metode optimasi yang digunakan dalam perhitungan ini yaitu Program Solver.Hasil yang diperoleh debit andalan yang tersedia di tampungan bendung cawak adalah 2,547 m3/detik. kebutuhan air irigasi dengan pola tanam Palawija-Padi-Padi awal tanam Agustus I itu sebesar 0,579 lt/dtk/ha sebagai rencana tanam dengan kebutuhan air paling minimum.Serta optimasi didapatkan pola tanam dan awal tanam yang paling optimum adalah Agustus I dengan pola tanam Palawija-Padi-Padi intensitas tanam 291% dan dengan luas areal irigasi MT I 675 ha, MT II 742 ha, MT III 742 ha.


2015 ◽  
Vol 72 (4) ◽  
pp. 579-584 ◽  
Author(s):  
A. Muramatsu ◽  
H. Ito ◽  
A. Sasaki ◽  
A. Kajihara ◽  
T. Watanabe

To achieve enhanced nitrogen removal, we modified a cultivation system with circulated irrigation of treated municipal wastewater by using rice for animal feed instead of human consumption. The performance of this modified system was evaluated through a bench-scale experiment by comparing the direction of circulated irrigation (i.e. passing through paddy soil upward and downward). The modified system achieved more than three times higher nitrogen removal (3.2 g) than the system in which rice for human consumption was cultivated. The removal efficiency was higher than 99.5%, regardless of the direction of circulated irrigation. Nitrogen in the treated municipal wastewater was adsorbed by the rice plant in this cultivation system as effectively as chemical fertilizer used in normal paddy fields. Circulated irrigation increased the nitrogen released to the atmosphere, probably due to enhanced denitrification. Neither the circulation of irrigation water nor its direction affected the growth of the rice plant and the yield and quality of harvested rice. The yield of rice harvested in this system did not reach the target value in normal paddy fields. To increase this yield, a larger amount of treated wastewater should be applied to the system, considering the significant amount of nitrogen released to the atmosphere.


2015 ◽  
Vol 7 (1) ◽  
pp. 39-51 ◽  
Author(s):  
Ali Fares ◽  
Ripendra Awal ◽  
Samira Fares ◽  
Alton B. Johnson ◽  
Hector Valenzuela

The impact of potential future climate change scenarios on the irrigation water requirements (IRRs) of two major agricultural crops (coffee and seed corn) in Hawai'i was studied using the Irrigation Management System (IManSys) model. In addition to IRRs calculations, IManSys calculates runoff, deep percolation, canopy interception, and effective rainfall based on plant growth parameters, site specific soil hydrological properties, irrigation system efficiency, and long-term daily weather data. Irrigation water requirements of two crops were simulated using historical climate data and different levels of atmospheric CO2 (330, 550, 710 and 970 ppm), temperature (+1.1 and +6.4 °C) and precipitation (±5, ±10 and ±20%) chosen based on the Intergovernmental Panel on Climate Change (IPCC) AR4 projections under reference, B1, A1B1 and A1F1 emission scenarios. IRRs decreased as CO2 emission increased. The average percentage decrease in IRRs for seed corn is higher than that of coffee. However, runoff, rain canopy interception, and deep percolation below the root zone increased as precipitation increased. Canopy interception and drainage increased with increased CO2 emission. Evapotranspiration responded positively to air temperature rise, and as a result, IRRs increased as well. Further studies using crop models will predict crop yield responses to these different irrigation scenarios.


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