Your search found 12 records
1 Foster, W. M.; Batchelor, C. H.; Bell, J. P.; Hodnett, M. G.; Sikurajapthy, S. 1989. Small-scale irrigation in Sri Lanka: Soil moisture status and crop response to drip irrigation. In Rydzewski, J. R.; Ward, C. F. (Eds.) Irrigation theory and practice. Proceedings of the International Conference, University of Southampton, 12-15 September. London: Pentech Press. pp.602-615.
Small scale systems ; Drip irrigation ; Furrow irrigation ; Evaluation ; Crops / Sri Lanka / Maha Illuppallama
(Location: IWMI-HQ Call no: 631.7 G000 RYD Record No: H07571)
This paper describes the evaluation of the irrigation efficiency of a low-cost, low-head drip irrigation system in the Dry Zone of Sri Lanka. The Institute of Hydrology set up field trails in which soil moisture regime and plant growth of four vegetable crops irrigated using the drip system were monitored and compared with controls irrigated by conventional furrow methods. This paper discusses the analysis for two of the crops: chilli (Capsicum annuum) and onion (Allium cepa). Although irrigation efficiencies were much greater for the drip irrigated crops, some yield reduction was noted. Recommendations are made that will lead to greater water savings and, possibly, higher yields under drip irrigation.
2 Miller, E.; Tillson, T. J. 1989. Small scale irrigation in Sri Lanka: Field trials of a low head drip system. In Rydzewski, J. R.; Ward, C. F. (Eds.), Irrigation theory and practice. Proceedings of the International Conference, University of Southampton, 12-15 September. London: Pentech Press. pp.616-629.
Small scale systems ; Drip irrigation ; Field tests / Sri Lanka / Korakehawewa / Anuradhapura / Maha Illuppallama
(Location: IWMI-HQ Call no: 631.7 G000 RYD Record No: H07547)
3 Tase, N.; Shimada, J.; Tanaka, T. (Eds.) 1995. Hydrological study data in Sri Lanka: Data book of "hydrological cycle in humid tropical ecosystems." Part II. Special Research Project on Global Environmental Change, University of Tsukuba, Japan. iii, 110p.
Soil properties ; Water quality ; Precipitation ; Rivers ; Groundwater ; Catchment areas ; Soil water / Sri Lanka / Peradeniya / Batalagoda / Puttalam / Maha Illuppallama
(Location: IWMI-HQ Call no: 551.48 G744 TAS Record No: H018476)
4 Batchelor, C.; Lovell, C.; Murata, M. 1996. Simple microirrigation techniques for improving irrigation efficiency on vegetable gardens. Agricultural Water Management, 32(1):37-48.
Irrigation efficiency ; Small scale systems ; Vegetables ; Drip irrigation ; Subsurface irrigation ; Pitcher irrigation ; Pipes / Zimbabwe / Sri Lanka / Maha Illuppallama
(Location: IWMI-HQ Call no: PER Record No: H019752)
5 Somasiri, S. 1981. Land, water and crop management under irrigation in the dry zone of Sri Lanka: Agrotechnical information. Unpublished research report prepared for the Mahaweli Research Committee. 62p.
Climate ; Geology ; Geomorphology ; Soils ; Crops ; Evapotranspiration ; Irrigation water ; Water use ; Land management ; Water management ; Sprinkler irrigation ; Efficiency ; Surface irrigation ; Furrow irrigation ; Irrigated farming ; Basin irrigation ; Irrigation practices ; Water balance ; Catchment areas ; Water table ; Groundwater ; Drainage ; Sugarcane ; Land development ; Costs ; Crop production ; Settlement / Sri Lanka / Mahaweli Project / Kalankuttiya / Kantalai / Maha Illuppallama / Pelwehera
(Location: IWMI-HQ Call no: P 4897 Record No: H022661)
6 Shunmugathasan, K. N.; De Costa, W. A. J. M.; Joseph, K. D. S. M. 1996. Effects of irrigation at different growth stages on yield components and yield of soybean (Glycine max (L.) Merr.) grown in the low country dry zone of Sri Lanka. In Peiris, C. N. (Ed.), Tropical agricultural research. Vol.8, 1996: Proceedings of the 8th Annual Congress of the Postgraduate Institute of Agriculture, Peradeniya, Sri Lanka, 21-22 Nov. 1996. Peradeniya, Sri Lanka: PGIA. pp.1-10.
(Location: IWMI-HQ Call no: 630.72 G744 PEI Record No: H023274)
7 CH2M Hill, Inc. 1979. Proposed Water Management Program for Major Irrigation Schemes in Sri Lanka. Report prepared for USAID. v.p.
Water resource management ; Irrigation programs ; Development projects ; Development aid ; Land use ; Settlement ; Drainage ; Water reuse ; Water delivery ; Water loss ; Water use efficiency ; Rice ; Paddy fields ; Tillage ; Water supply ; Institutions ; Farmers' associations ; Social organization ; Farmer-agency interactions ; Training ; Agricultural extension ; Higher education ; Operations ; Maintenance ; Rehabilitation ; Project planning ; Costs ; Organizational change ; Irrigation canals ; Economic evaluation ; Benefits ; Crop production ; Crop yield ; Environmental effects ; Water budget / Sri Lanka / Uda Walawe Project / Gal Oya Project / Maha Illuppallama / Kaudulla / Uda Walawe / Rajangane / Galgamuwa / Senanayake Samudra
(Location: IWMI-HQ Call no: P 5303 Record No: H024910)
8 Anputhas, M.; Samita, S.; S. De Z. Abeysiriwardena. 2003. Multivariate approach in varietal recommendations. Tropical Agricultural Research, 15:207-216.
(Location: IWMI-HQ Call no: P 6632 Record No: H033445)
9 Kumari, M. K. N.; Navaratne, C. M. 2006. Improving water security for crop production through agro-climatic approach: a case study in Anuradhapura. In Dayawansa, N. D. K. (Ed.). Water resources research in Sri Lanka: symposium proceedings of the Water Professional’s Day 2006, Postgraduate Institute of Agriculture, University of Peradeniya, Sri Lanka, 1 October 2006. Peradeniya, Sri Lanka: University of Peradeniya. Postgraduate Institute of Agriculture (PGIA). pp.135-143.
Crop production ; Irrigation requirements ; Rice ; Rain ; Evapotranspiration ; Tanks ; Reservoirs / Sri Lanka / Maha Illuppallama
(Location: IWMI HQ Call no: 631.7 G744 DAY Record No: H040730)
10 Amarasingha, R. P. R. K.; Suriyagoda, L. D. B.; Marambe, B.; Gaydon, D. S.; Galagedara, L. W.; Punyawardena, R.; Silva, G. L. L. P.; Nidumolu, U.; Howden, M. 2015. Simulation of crop and water productivity for rice (Oryza sativa L.) using APSIM under diverse agro-climatic conditions and water management techniques in Sri Lanka. Agricultural Water Management, 160:132-143. [doi: https://doi.org/10.1016/j.agwat.2015.07.001]
Water productivity ; Water management ; Rice ; Crop management ; Agroclimatic zones ; Irrigation water ; Rain ; Water requirements ; Plant establishment ; Farmers / Sri Lanka / Maha-Illuppallama / Bathalagoda / Bombuwela / Dambadeniya / Maradankalla / Thabbowa
(Location: IWMI HQ Call no: e-copy only Record No: H047402)
(0.93 MB)
The APSIM–Oryza model has been used worldwide to evaluate the impact of diverse management practices on the growth of rice (Oryza sativa L.). Despite its importance, the crop productivity (kg ha-1) and water productivity (kg ha-1mm-1) of rice under moisture-limited (i.e. rainfed or rainfed with supplementary alternate wetting-and-drying (AWD) irrigation) farmer-field conditions in tropical South-Asia has received little attention in modelling exercises. Benefits of aligning crop establishment with the onset of rainfall to reduce dependency on supplementary irrigation and improve crop and water productivities have not yet been quantified in Sri Lanka. Therefore, we parameterised and evaluated the APSIM–Oryza model for two widely grown Sri Lankan short- and medium-duration rice varieties. The model estimated the grain yield of rice under moisture-limited farmer-field conditions with a strong fit (n = 24, R2 > 0.97, RMSE= 484 kg ha-1), across cultivation year, season, time of establishment (i.e. with rainfall onset or date-specific planting), variety and/or water management practice (i.e. totally rainfed or rainfed with supplementary irrigation). A climatic analysis indicated that the farmers regularly establish rice crops 2–4 weeks after the rainfall onset. This is a consequence of the current practice of setting the date for crop establishment at pre-season cultivation meetings without a scientifically-validated rainfall forecast. The same analysis revealed that an early onset to the rainy season resulted in longer seasons with more rain than late onset. When the onset of rainfall is delayed, crop modelling scenarios using the validated APSIM model showed an increased dependence on supplementary irrigation for rice cultivation. Alternatively, in years when an early onset was observed, late planting in the season reduced the use of rain water by 95% while increasing the irrigation water requirement by 11% compared with planting at rainfall onset. Access to supplementary with AWD irrigation increased the stability of grain yield, and crop and water productivity, irrespective of the onset of rainfall or time of crop establishment.
11 Amarasingha, R. P. R. K.; Suriyagoda, L. D. B.; Marambe, B.; Rathnayake, W. M. U. K.; Gaydon, D. S.; Galagedara, L. W.; Punyawardena, R.; Silva, G. L. L. P.; Nidumolu, U.; Howden, M. 2017. Improving water productivity in moisture-limited rice-based cropping systems through incorporation of maize and mungbean: a modelling approach. Agricultural Water Management, 189:111-122. [doi: https://doi.org/10.1016/j.agwat.2017.05.002]
Water productivity ; Cropping systems ; Intercropping ; Rice ; Maize ; Mung beans ; Water requirements ; Irrigation water ; Supplemental irrigation ; Simulation models ; Performance evaluation ; Crop yield ; Soil moisture ; Risk assessment ; Agroclimatic zones / Sri Lanka / Aralaganwila / Bathalagoda / Bombuwela / Maha-Illuppallama / Maradankalla / Vanathawilluwa / Weerawila
(Location: IWMI HQ Call no: e-copy only Record No: H048189)
(1.01 MB)
Crop and water productivities of rice-based cropping systems and cropping patterns in the irrigated lowlands of Sri Lanka have not been researched to the degree warranted given their significance as critical food sources. In order to reduce this knowledge gap, we simulated the water requirement for rice, maize, and mungbean under rice-based cropping systems in the Dry Zone of Sri Lanka. We evaluated the best combinations of crops for minimum water usage while reaching higher crop and water productivities. We also assessed the risk of cultivating mungbean as the third season/sandwich crop (i.e. rice-mungbean-rice) in different regions in Sri Lanka. In the simulation modelling exercise, APSIM-Oryza (rice), APSIM-maize and APSIM-mungbean modules were parameterised and validated for varieties grown widely in Sri Lanka. Moreover, crop productivities and supplementary irrigation requirement were tested under two management scenarios i.e. Scenario 1: irrigate when plant available water content in soil fell below 25% of maximum, and Scenario 2: irrigate at 7-day intervals (current farmer practice). The parameterised, calibrated and validated model estimated the irrigation water requirement (number of pairs of observations (n) = 14, R2 > 0.9, RMSE = 66 mm season-1 ha-1), and grain yield of maize (n = 37, R2 > 0.95, RMSE = 353 kg ha-1) and mungbean (n = 26, R2 > 0.98, RMSE = 75 kg ha-1) with a strong fit in comparison with observed data, across years, cultivating seasons, regions, management conditions and varieties. Simulated water requirement during the cropping season reduced in the order of rice (1180–1520 mm) > maize and mungbean intercrop = maize sole crop (637–672 mm) > mungbean sole crop (345 mm). The water productivity of the system (crop yield per unit water) could be increased by over 65% when maize or mungbean extent was increased. The most efficient crop combinations to maximise net return were diversification of the land extent as (i) 50% to rice and 50% to mungbean sole crops, or (ii) 25%, 25% and 50% to rice, maize and mungbean sole crops, respectively. Under situations where water availability is inadequate for rice, land extent could be cultivated to 50% maize and 50% mungbean as sole crops to ensure the maximum net return per unit irrigation water (115 Sri Lankan Rupees ha-1 mm-1). Regions with high rainfall during the preceding rice cultivating season are expected to have minimum risk when incorporating a third season mungbean crop. Moisture loss through evapotranspiration from the third season mungbean crop was similar to that of a fallowed site with weeds.
12 Wickramasinghe, M. R. C. P.; Dayawansa, N. D. K.; Jayasiri, M. M. J. G. C. N.; De Silva, R. P. 2023. A study on external pressures of an ancient irrigation cascade system in Sri Lanka. Agricultural Systems, 205:103593. [doi: https://doi.org/10.1016/j.agsy.2022.103593]
Irrigation ; History ; Villages ; Tanks ; Systems ; Water quality ; Agrochemicals ; Runoff ; Land use change ; Climate variability ; Population growth ; Intensification ; Farming systems ; Water management ; Arid zones ; Agroclimatic zones ; Precipitation ; Water availability ; Sustainability ; Fertilizers ; Salinity ; Soil erosion ; Forest cover ; Water management / Sri Lanka / Anuradhapura / Maha Illuppallama / Mahakanumulla
(Location: IWMI HQ Call no: e-copy only Record No: H051615)
(3.87 MB)
CONTEXT: Village Tank Cascade Systems (VTCSs), which are ancient irrigation systems in Sri Lanka have undergone various pressures over time including climate variability, population growth, land use changes and agricultural intensification. VTCSs have provided irrigation and vital ecosystem services for generations, while facing these pressures. As external pressures have increased drastically over the last century, it is worthwhile to investigate VTCS's current capacity to tolerate pressures exerted on them while sustaining their functions.
OBJECTIVE: The objectives of this study were to (i) assess the pressures exerted on Mahakanumulla VTCS due to climate change, population growth, land use changes and agricultural practices, (ii) evaluate the impacts of the pressures on the system in terms of water quality and quantity.
METHODS: Rainfall data from 1906 to 2020 were analyzed to identify the rainfall trends over the last century. Land use maps were developed for 1910, 1979, 2002 and 2018. To identify current farming practices, a questionnaire survey was carried out targeting 357 respondents followed by field investigations. Environmental impacts due to pressures on the system were evaluated using water quantity estimations and quality tests.
RESULTS AND CONCLUSIONS: Paddy extent has increased from 6.3% to 20.2% while the homestead extent has increased from 1.6% to 11.5% during the last century. The lands used for sustainable shifting cultivation have encroached with permanent agricultural lands and human settlements. The runoff coefficient rose from 0.29 to 0.45, indicating a high outflow of water during rains and limiting water retention within the system. This is an indication of increasing water scarcity in dry periods due to limited recharge capacity. Although the system continues to function without significant water quality deterioration, agricultural activities can cause threats in the future. Hence, the system needs immediate attention in the context of proper land use planning, farmer awareness and integrated nutrient management at the cascade level to minimize these pressures exerted upon the system.
SIGNIFICANCE: Identifying and quantifying various pressures exerted on VTCSs is the fundamental step in setting management and mitigation plans. Project planners and policymakers need evidence-based information in this regard. Therefore, this study's findings and the research framework that may be extended to other VTCSs and similar systems are significant in creating a favorable policy environment and implementation programmes to reduce the risks the VTCSs are exposed to.
OBJECTIVE: The objectives of this study were to (i) assess the pressures exerted on Mahakanumulla VTCS due to climate change, population growth, land use changes and agricultural practices, (ii) evaluate the impacts of the pressures on the system in terms of water quality and quantity.
METHODS: Rainfall data from 1906 to 2020 were analyzed to identify the rainfall trends over the last century. Land use maps were developed for 1910, 1979, 2002 and 2018. To identify current farming practices, a questionnaire survey was carried out targeting 357 respondents followed by field investigations. Environmental impacts due to pressures on the system were evaluated using water quantity estimations and quality tests.
RESULTS AND CONCLUSIONS: Paddy extent has increased from 6.3% to 20.2% while the homestead extent has increased from 1.6% to 11.5% during the last century. The lands used for sustainable shifting cultivation have encroached with permanent agricultural lands and human settlements. The runoff coefficient rose from 0.29 to 0.45, indicating a high outflow of water during rains and limiting water retention within the system. This is an indication of increasing water scarcity in dry periods due to limited recharge capacity. Although the system continues to function without significant water quality deterioration, agricultural activities can cause threats in the future. Hence, the system needs immediate attention in the context of proper land use planning, farmer awareness and integrated nutrient management at the cascade level to minimize these pressures exerted upon the system.
SIGNIFICANCE: Identifying and quantifying various pressures exerted on VTCSs is the fundamental step in setting management and mitigation plans. Project planners and policymakers need evidence-based information in this regard. Therefore, this study's findings and the research framework that may be extended to other VTCSs and similar systems are significant in creating a favorable policy environment and implementation programmes to reduce the risks the VTCSs are exposed to.
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