Relative Irrigation Supply Research Articles

Overall performance assessment of selected small-scale irrigation schemes using internal and external performance indicators in West Hararghe Zone, Eastern Ethiopia

This study was conducted to evaluate the overall performance of selected small-scale irrigation schemes using internal and external performance indicators. The performance of the irrigation schemes in relation to water balance was evaluated using three indicators. The results indicated that the relative water supply (RWS), relative irrigation supply (RIS), and field application ratio (FAR) of Midagdu irrigation scheme were 0.9, 1.3, and 0.75 respectively. This indicates that the water supply is not closely related to the water demand. However, for the Wadeti Irrigation scheme, the RWS, RIS, and FAR are 0.48, 0.35, and 2.83, respectively, indicating water stress. The Midagdu irrigation scheme shows 7496.75 birr/ha for both output per unit command area and output per unit cropped area. Output per unit irrigation water supply was 12.5 birr/m3, while output per unit water consumed was 4.4 birr/m3. For the Wadeti irrigation scheme, the values were 11,276.12 birr/ha, 11,276.12 birr/ha, 8.7 birr/m3, and 1.6 birr/m3, respectively. This study results showed that the Wadeti irrigation scheme is more land-efficient, while the Midagdu scheme is more water-efficient. The values of the hydraulic performance indicators Conveyance Efficiency (Ec), Water delivery capacity (WDC), and Delivery Performance Ratio (DPR), for the Midagdu irrigation scheme were 75 %, 0.45, and 0.8, respectively, while for the Wadeti irrigation scheme, the values were 42 %, 0.11, and 0.4, respectively. These results indicate that the water delivery performance of the two schemes was poor. Therefore, improving the hydraulic performance of the scheme requires minimizing water conveyance losses.

Performance evaluation of the Bilate and Furfuro irrigation schemes in Silti Zone, southern Ethiopia

Many irrigation schemes are performing poorly for a number of reasons, and this should be improved to increase the efficiency and productivity of the schemes. This study attempted to determine the performance of the Bilate and Furfuro irrigation schemes in Silti Zone, southern Ethiopia. For field data measurements, three farmers’ fields were selected at the head, middle, and tail end of each scheme. Average conveyance efficiencies were 53% and 56.1%, average field application efficiencies were 55.9% and 58.0%, average water storage efficiencies were 53% and 46.5%, irrigation uniformity was 91.03% and 92.9%, and overall irrigation efficiency was 28% and 32% for Bilate and Furfuro schemes respectively. This implied that the two schemes were performing inefficiently and inadequately, but water was distributed uniformly. The reason might be most canal sections had unreasonable losses of water in two schemes. Additionally, relative water supply was 0.68 and 0.79, relative irrigation supply was 0.61 and 0.77, output per unit irrigated area was 4140.4 and 1781.5 ($/ha), output per unit command area was 4510.3 and 1968.5 ($/ha), output per unit irrigation supply was 0.94 and 0.28 ($/m3), output per unit water consumed was 0.99 and 0.39 ($/m3), sustainability of irrigation area was 1.05 and 1.02, and irritation ratio was 1.11 and 1.09 for Bilate and Furfuro schemes respectively. This revealed that the applied water was not satisfied the crop water demand, but their irrigated lands were expanded for two irrigation schemes. Furfuro scheme was better than Bilate in terms of relative water supply and relative irrigation supply, but their results obtained were below acceptable values. However, Bilate scheme had significantly better land and water productivity than Furfuro scheme. This may be use high value crops, better agricultural inputs, and removal of grass cover and sedimentation from canal systems. Hence, Bilate irrigation scheme was better performing than Furfuro scheme. Therefore, adopt the best practices learned from Bilate irrigation scheme for the Furfuro scheme.

Hydro-economic basin impacts of extensive adoption of deficit irrigation by farmers: Are we overestimating water resources?

Deficit irrigation (DI) is an agronomic practice in which the volume of irrigation water applied is below maximum yield requirements, usually during drought-sensitive growth stages. DI is often used when water is scarce, and farmers need to either reduce the irrigated area or reduce the water supply to the existing irrigated area. This research presents an agroeconomic model of field efficiencies and related losses to study the relationship between DI adoption and return flows (RF). Results show that RF are significantly overestimated when DI is widely adopted as there are no losses when relative irrigation supply (ν) is low. The hydrological impact at basin level has been illustrated for the Guadalquivir River Basin, showing that RF and water resources are substantially overestimated when constant efficiency values (an assumption common to many hydrological models) are used without including the impact of DI on RF.

Assessment of irrigation water allocation, Koftu, Ethiopia

Abstract This research investigates the fair and efficient distribution of water among irrigators, focusing on the timely and uniform delivery of water. To achieve this, the study utilized various methods such as group discussions, critical informant and expert interviews, and field flow measurements. The degree of fairness in the distribution of irrigation water was determined by analyzing the shift in the relative water supply to end users. The effectiveness of irrigation is inversely proportional to the relative irrigation supply, which can be observed in the scheme's water delivery indicators. The study found that while the estimated delivered flow of water in the head, middle, and tail reaches of the canal was 1.21, 0.58, and 0.23 m3/s respectively, the required quantity of discharge was only 0.81, 0.31, and 0.15 m3/s. This discrepancy resulted in the inadequate, unreliable, and unequal water supply to irrigators. The research revealed that canal operation and maintenance were the main factors limiting the system's capacity. The findings showed that the adequacy, dependability, equality, and efficiency values were 0.8, 0.14, 0.40, and 0.71, respectively, suggesting that improvements are needed to ensure the timely and equitable distribution of water to irrigators.

Benchmarking of Irrigation Performance in Karataş and Karaçal Irrigation Associations

This study was carried out to evaluate the system performances of Karataş and Karaçal irrigation associations located in Burdur province. Karataş irrigation association was put into operation in 1982 and Karaçal irrigation association in 2015 with irrigation areas are 5476 and 4975 ha, respectively. The same public personnel were appointed to both irrigation associations as the Head of the Association in 2018, and as of 2019, both irrigation Associations were gathered under the management of Karataş irrigation association. In this study, the performances of Karataş irrigation, which has an old and predominantly open canal system, and Karaçal irrigation systems, which are relatively new and have a pressurized irrigation system, between the years 2015-2019 have been evaluated. In the performance evaluation, a set of indicators under two main headings as water use efficiency, and financial efficiency recommended by the International Technology and Research Program in Irrigation and Drainage (IPTRID) was used. According to the results of the research, when the water use efficiency is examined, especially Annual relative irrigation supply (0.53-0.73 for Karataş; 0.47-0.96 for Karaçal) and irrigation ratio (20-72% for Karataş; 36% for Karaçal) 55) values were not at the desired levels. In terms of Financial Efficiency, cost recovery ratio (119-401% for Karataş; 144-311 for Karaçal) and revenue collection performance (78-442% for Karataş; 10-130 for Karaçal) were found to be high. Although this is a new irrigation, Karaçal irrigation shows that relatively high maintenance costs are incurred. Total operating maintenance and management (MOM) cost per unit area is US$ 9.60-14.98/ha for Karataş and as 1.32-22.92 US$/ha for Karaçal. These values showed that, in general, both irrigations have sufficient financial strength.

Analysis of water–energy–crop nexus indicators in irrigated sugarcane of Awash Basin, Ethiopia

Pressures on limited resources of water and energy in agriculture forced researchers to look for alternative approaches towards the solutions integrating the resources. Since the development of the water–energy–food (WEF) nexus concept, several methods including indicator approaches have been developed and are in use to analyze their linkages. The aims of the study have been to determine and compare the performances of sugarcane producing irrigation schemes and technologies in Awash Basin of Ethiopia. Water applied, input energy used and productivity of eleven irrigation schemes found in Wonji, Metehara and Kessem sugar factories have been used and the performances of each scheme were evaluated. Based on statistical analyses, irrigation schemes were grouped into gravity surface, pump surface and pump sprinklers. After normalizing the original data through min–max, performance scores were determined based on equal weight and entropy methods. Categorical assessments revealed that gravity surface schemes had the highest total input energy use and energy productivity scores while pump sprinkler schemes were better on the water applied, relative irrigation supply and water productivity indicators. However, regarding composite performance indicators or WEF nexus indices, pump surface schemes scored the highest followed by gravity surface schemes while sprinklers were the least. The study proved the emphasis of the sugar factories of the basin for crop productivity with the expenses of energy and water utilizations. Hence, improvements in water management of gravity surface schemes and energy utilization of sprinkler schemes were recommended as key solutions for balanced resource use as well as the overall sustainability of the sector.

Evaluation of water delivery performance of right main canal of Bhimsagar medium irrigation scheme, Rajasthan

ABSTRACT This research investigation aims to evaluate the performance of the Right Main Canal (RMC) of the Bhimsagar medium irrigation scheme in Rajasthan, India, employing water delivery and water use indicators, such as adequacy, equity, dependability, relative water supply, and relative irrigation supply. The three minors chosen were Ratanpura at the head, Chaplada at the middle, and Maraita II at the tail reach on RMC. The volume of water diverted into the selected minors from the right main canal was measured during crop season, and crop water demand in the command area of each minor was computed using the CROPWAT 8.0 software. Overall, RMC adequacy was adequate at the head, and middle reach minors but inadequate for the tail reach minor. The water distribution system was determined to be unreliable regarding water supply concerning time, with a dependability value of 0.49. Overall equity was determined to be good to fair for the head and middle reach minors but poor for tail reach minor due to disparity in water distribution. In 2013–14, RWS and RIS showed insufficiency in the command system. The average values of RWS and RIS were found to be 1.00 and 1.43, respectively.

Orchard Level Assessment of Irrigation Performance and Water Productivity of an Irrigation Community in Eastern Spain

Over the last three decades, a great investment effort has been made in the modernization of irrigation in the Valencian Community (Spain). The initial change from distribution networks to pressurized ones and the shift towards drip irrigation systems was followed by improvements in irrigation scheduling, based on agrometeorological data, soil water content sensors, and remote sensing. These improvements are considered adequate for increasing irrigation water use efficiency, but it is difficult to find systematic measurements to assess its impacts on irrigation adequacy along with irrigation productivity in fruit orchards. This work presents the results of a four year assessment of irrigation water and energy use efficiency along with water productivity of a recently established irrigation community in the province of Valencia (Spain). The study was carried out at the orchard level and focused on two fruit crops: persimmon and peach trees. Six irrigation performance indicators, relative water supply (RWS), relative irrigation supply (RIS), yield performance (Yp), global water productivity (WPoverall), output per unit irrigation water (OUI), and the percent of nitrogen fertilization obtained by irrigation water, were defined and calculated for years 2017 to 2020 in 104 persimmon and peach orchards. The results showed that most of the farmers irrigated below the crop water requirements, showing RWS and RIS values less than 1, and there was great variability among farmers, especially in WPoverall and OUI indicators.

Evaluating irrigation scheme performance in a tropical environment: The Guanacaste scheme, Costa Rica*

AbstractIrrigation is expanding in the tropics and could make an important contribution to the intensification of production in those tropical areas where a dry season limits productivity. A study was carried out to characterize irrigation performance and the yield gaps of a tropical irrigation scheme that covers more than 41 000 ha in northern Costa Rica. The study covered a 5‐year period, from 2014 to 2018. The performance indicator relative irrigation supply (RIS) ranged between 2.48 and 3.78, values higher than those typically observed in schemes of temperate areas, but in the low range of those documented in the tropics. Despite the excess of water usage, it was found that there were farms with water shortages, especially in the canal tails during the dry season, but there was also damage caused by excess of water in the rainy season. The potential yield of the two main crops (rice and sugar cane) was determined with the AquaCrop simulation model. Actual yields were determined via a farmers' survey that also inquired about irrigation management issues. Yield gaps were determined for each of the two sectors that make up the irrigation scheme (South and West canals). The mean yield gap of rice in the South Canal sector (3.34 t ha−1) was smaller than that of the West Canal sector (4.84 t ha−1). The highest yield gap of rice occurred in the rainy season in the West canal sector. The yield gap of sugar cane in the West canal sector was significantly larger than that in the South canal sector (170 and 148 t ha−1, respectively). A farmers' survey, combined with an examination of soil maps, revealed that poor drainage through the heavy soils that predominate in the West canal sector is one of the main causes of the large yield gap, in both rice and sugar cane. While users are relatively satisfied with the provision of irrigation water and its cost, several opportunities (e.g. water delivery, amount of fertilizer in sugar cane, water supply and irrigation system on farms) for improving scheme performance and for closing the yield gaps are discussed.

Evaluation of irrigation adequacy in sugarcane systems in Eswatini

The adoption of objective irrigation scheduling approaches in the sugarcane industry has been very slow leading to over-irrigation, low water use efficiency, and consequently, low returns. With the widespread use of subjective scheduling, there is also a perception that there are no significant benefits derived from objective scheduling. A study was, therefore, conducted in Eswatini to determine the performance of irrigation systems that were using subjective irrigation scheduling. More specifically, the objective of the study was to determine the irrigation adequacy fora sugarcane crop that was under two overhead systems viz. centre pivot and sprinkler irrigation. Adequacy was determined in terms of relative irrigation supply (RIS) for the 2015/16 season. The CROPWAT 8.0 model was used to estimate crop demand in terms of net irrigation requirement, whilst the amount of water applied during the period was the supply. Seasonal RIS results indicated that the area under the centre pivot was slightly over-irrigated (RIS= 1.13), whilst irrigation in the area under the sprinkler system was found to be adequate (RIS= 0.94). MonthlyRIS values, however, revealed that the crop was over-irrigated most of the time. The crop under the centre pivot was over-irrigated for the months of January, June, July, September, November, and December as indicated by the RIS values of 1.17, 1.33, 1.20, 1.77, 3.35, and 15.09, respectively. Over-irrigation under the sprinkler system was observed in June, July, September, October, and November where the RIS was 1.36, 2.19, 2.91, 1.77, and 1.67, respectively. In both irrigation systems, over-irrigation was experienced at the germination and establishment phases of development. In contrast, all of the months with acceptable RIS values were found to be within the grand growth phase. It was, therefore, concluded that the scheduling approach used in the area was biased towards the grand growth phase. Hence, it was recommended that the irrigation schedule be modified to accommodate each of the different phases of sugarcane development.

Spatial and temporal variability analysis of green and blue evapotranspiration of wheat in the Egyptian Nile Delta from 1997 to 2017

Assessing green and blue water evapotranspiration (GWET and BWET) is the key to water resources management and improving water productivity. This study focuses on assessing, evaluating and managing evapotranspiration in Egyptian Nile Delta over 1997–2017 for thirteen regions. The monthly data of minimum and maximum temperatures, precipitation and solar radiation from November to May were derived from open access data for calculation of reference evapotranspiration and rainfall accounts. Wheat crop coefficient (Kc) values were estimated using the air temperature and base temperature of crop. GWET and BWET were calculated and mapped for each region in the ArcGIS environment. Land use land cover (LULC) was analyzed during 1997, 2005, 2011, and 2017 using Landsat images. The main findings of the research are as follows: (1) average values of crop coefficients Kc-init, Kc-mid and Kc-end were 0.72, 1.13, and 0.41 through initial, middle, and end growing seasons, respectively; (2) the best regions for saving green and blue water were Sidi-Salim, Bilqas, Ar-Riyad, Al-Hamul, and Biyala; (3) the total water saved was 4.80% and 53.12% of blue and green water accounts; (4) high coefficients of determination between precipitation, GWET, and BWET proportions were 0.99 for both. Furthermore, relative irrigation supply is a good indicator for predicting GWET and BWET with determination coefficients of 0.99 and 0.76, respectively. It can be concluded that the data integration of geographic information and LULC changes is the best way for water management and sustainable agro system development under limited water resources.

A global analysis of irrigation scheme water supplies in relation to requirements

The performance of irrigation schemes around the world has been below expectations. The assessment of irrigation performance is an essential step towards improving agricultural water use. One of the primary performance indicators is the relative irrigation supply (RIS, the ratio between the amount of water delivered and the crop net irrigation requirements). This study presents a worldwide analysis of irrigation scheme performance by evaluating key attributes that influence the RIS. The analysis was based on a review of reports and scientific papers that yielded 264 cases belonging to 25 countries in six world regions. The database was subjected to two types of statistical analysis: k-means clustering and analysis of covariance (ANCOVA). The cluster grouped irrigation schemes which were characterized by low RIS and advanced irrigation technology. The ANCOVA showed that the RIS co-varied significantly with the variation in precipitation, delivery schedule, on-farm irrigation systems, distribution network, and region, but not with the crop. The ANCOVA also showed that modern pressurized on-farm irrigation systems and on-demand distribution systems significantly improve RIS. The ANCOVA general linear model had a good capacity to predict RIS with a coefficient of determination of R2 = 0.83.

Performance Evaluation of Sanko Small Scale Irrigation Scheme at Basketo Special Woreda in SNNPR, Ethiopia

This study conducted to evaluate the performance of Sanko small-scale irrigation scheme at Basketo Special Woreda, South Nation Nationalities Peoples Regional states. The irrigation scheme includes command area of 120 ha and 600 beneficiaries. The scheme was evaluated using internal and productivity performance indicators. From the analyses of the internal performance indicators, the conveyance efficiency of the main canal was found to be 69.3% and application efficiencies at head (61.6%), middle (63.4%) and tail (46.5%) with average application efficiency of 57.2%. A light soil with high infiltration rates favors deep percolation losses at the top of the fields, resulting in low field application efficiency in tail end part of the scheme. A deep percolation ratio and storage efficiency of the scheme was found to be 42.8% and of 78.5% respectively. Generally overall scheme efficiency of scheme was 39.6%. From the evaluation of productivity indicators, the outputs per cropped area found as at head (84,706 Birr ha-1), middle (220,690 Birr ha-1) and tail (69,686.4 Birr ha-1) and the value of the outputs per command area of scheme was 15,003,276 Birr per command area. The output per unit irrigation supply of irrigation scheme was at head (13.5 Birr m-3), middle (33.95 Birr m-3) and tail (22.12 Birr m-3). Relative water supply and relative irrigation supply; found to be 1.28, which was the same for both since there was no rainfall during study period. From the analysis result, there was lower water use efficiency (WUE) at upper head (23.37 ton/m3) as compared to middle (48.78 ton/m3) and tail (60.22 (ton/ m3) part of the scheme in relation to yield obtained. Based on the evaluation result, highest yield was obtained from at middle part of irrigation scheme and lower yield was obtained from both upper and tail end part of the scheme. The yield reduction in upper and tail part of the scheme was due to over and under irrigation. However, there is still a room for improvement at all system levels. Therefore to reduce over and under irrigate; farmers should get awareness how to use, when to use and how much water used on their fields.

Modeling soil water balance and irrigation strategies in a flood-irrigated wheat-maize rotation system. A case in dry climate, China

Demand for irrigation water has been steadily increasing in arid regions where intensification of crop production is supported by flood-irrigation. An assessment of irrigation performance, water productivity, and irrigation schedules is critical to water conservation in dry climates. In this study, we conducted a field experiment to compare soil water balance in a flood-irrigated wheat-maize rotation system during the growing season of 2015–2016. We then modeled the soil water balance and improved irrigation strategies by coupling Hydrus-1D with the CROPWAT model, and using evapotranspiration calculated from climatic data. The calibrated Hydrus-1D model was used to simulate the temporal and spatial variation of evapotranspiration and deep percolation based on measured soil water distribution of soil profiles in the unsaturated zone. Results showed that using soil hydraulic parameters from inversion modeling can simulate soil water flow in multi-layer soil during a crop growing season. Simulation results indicated that about 36.6 and 40.6% (478.6 and 680.1 mm) of total water input in 2015 and 2016, respectively, was consumed by evapotranspiration. Furthermore, simulated deep percolation amounted for approximately 32.3 and 42.9% (403.9 and 696.6 mm) of the total amount of irrigation water in 2015 and 2016, respectively. These results indicated that only a small proportion of irrigation water was used by crops for transpiration. In addition, irrigation performance indicators such as relative water supply, relative irrigation supply, depleted fraction, and overall consumed ratio values indicated poor performance of irrigation practices in the study area. Particularly, crop yields did not increase with increases in irrigation water in flood-irrigated fields during the last ten years. Results of the CROPWAT model indicated that combinations of a fixed irrigation depth and timing, of 40 mm every 10 days, and 50 mm every 10 days were reasonable for wheat and maize, respectively, given the sandy soil in the study area. The improved irrigation strategies will limit water irrigation loss to 20% without significant effects on crop yields. This study provides an alternative approach for estimating deep percolation and crop water requirements supporting management efforts in water conservation in dry climates.

Performance Evaluation of Selected Surface Irrigation Schemes in Kachabira Woreda, SNNPRS, Ethiopia

This study was conducted to evaluate the comparative performances of two community-managed small scale irrigation schemes at Gemesha and Ufute with a command area of 48 ha and 40 ha using internal performance indicators. In order to evaluate the irrigation water use efficiency at the field level, nine farmer fields were selected from each irrigation schemes in relation to their location (from the head, middle and tail end water users). The internal performance indicators namely, in conveyance efficiencies, application efficiencies, deep percolation, storage efficiencies and irrigation uniformity shows (61.15 and 65.63%), (58.75 and 71.7%), (41.25 and 28.3%), (36.91% and 23.9%) and (98.32 and 97.79%) for Gemesha and Ufute respectively. The irrigation ratio results for physical sustainability indicator shows 0.32 and 0.4 for Gemesha and Ufute irrigation respectively. The result of relative Irrigation Supply for both irrigation schemes was higher than one, this shows that there were over supply of water in both irrigation schemes for Gemesha and Ufute respectively. Based on the assessment carried out, Ufute irrigation scheme performed better than Gemesha irrigation scheme. But there is still a room for improvement of the performance of both irrigation schemes. Keywords: Internal indicators, efficiency, deep percolation, irrigation,

Connecting Drip Irrigation Performance to Farmers’ Practices: The Case of Greenhouse Horticulture in the Algerian Sahara

AbstractDrip irrigation is widely used in a range of different farming systems. Farmers generally adapt drip irrigation systems to their specific conditions. Irrigation performance is usually related to the hydraulic parameters of drip irrigation, and is usually expressed as a single static value. We developed a comprehensive approach to account for irrigation performance as a dynamic process, which evolves continuously due to changes in the way farmers schedule irrigation and renew irrigation equipment. The performance of drip irrigation systems used for greenhouse horticulture was evaluated in south‐east Algeria in the 2012–2013 growing season. Two indicators were evaluated—distribution uniformity and water stress level. The approach was applied to 25 greenhouses owned by 13 farmers. Results revealed that the performance of drip irrigation systems is a dynamic process. We showed that farmers have integrated certain irrigation performance indicators such as distribution uniformity and water stress levels in their practices, as they have visible effects on crop production. Conversely, the relative irrigation supply does not directly interest the farmers, and was consequently not incorporated in their irrigation practices. We conclude that measuring drip irrigation performance must be accompanied by a broader understanding of the farming systems in which drip irrigation is used. Copyright © 2018 John Wiley & Sons, Ltd.

English

Assessing the performance of an irrigation scheme is an important management function which will indicate the state of the scheme and suggest possible remedial measures to improve the effectiveness of the scheme. This study was conducted to assess the technical and agricultural performances of the Okyereko irrigation scheme in the Central Region of Ghana. Secondary data were collected from the scheme with respect to rainfall, yield for the period of 2011 to 2015 seasons whilst field measurements were carried out to determine the water supply and demand. This study assessed three technical performance indicators and two agricultural performance indicators during the 2014/2015 season. The V-notch and the rectangular weir were used to measure the water delivery and the Manning formula was used to calculate the flow-rates in canals. Water requirements were estimated using the modified Penman method. The results from this study indicated an overall scheme conveyance efficiency of 78.2%, a maximum dependability of irrigation intervals between water applications of 2 and a scheme relative irrigation supply of 1.38. The agricultural performance indicators, output per unit irrigation supply and water productivity per unit crop evapotranspiration (ET), were found to be 0.90 and 20.53 kgm-3, respectively for rice. This study recommends that farmers should be actively involved in all performance assessments and scheme organizations in order to improve the performance since the farmers are major stakeholders of irrigation schemes and are responsible for operation and maintenance after the introduction of Participatory Irrigation Management. Keywords: Irrigation scheme, agricultural productivity, performance assessment.

Performance Evaluation of Water Delivery System for Command Area of Left Main Canal of Bhimsagar Irrigation Project, Rajasthan

Water delivery performance of left main canal of Bhimsagar irrigation project, Rajasthan was studied. Outlet-wise performance was evaluated using the adequacy, equity, dependability, relative irrigation supply and relative water supply indicators. These indicators were studied for the 21 outlets located on three minors at head, middle and tail reach of the left main canal for the 5-month irrigation period during Rabi season, using measured water deliveries and calculated crop water requirements. The outlet-wise water delivery performance indicators showed poor performance of the system. Considering the irrigation season and the system as a whole, the average value of indicator’s were found as “poor” for adequacy, equity and dependability; emphasizing for adopting improved management strategies.

Assessment of Irrigation Practices of Farmers Receiving Water from Open-Canal and Piped Irrigation Networks

Open-canal irrigation networks have been transformed into closed-piped networks. Drip irrigation is the most common method used irrigations in Çanakkale province. The aim of study is to assess irrigation practices of farmers using different irrigation networks. There were not significant differences in irrigation practices of the farmers receiving water from both networks, but all were making mistakes and unconscious in their practices. An optimum schedule was also prepared to compare with farmer practices. While a farmer growing tomato in Kumkale village with piped-network was expected to apply 531 mm irrigation water as seasonal total, present farmer applied 1414 mm water; while a farmer growing tomato in Mahmudiye village with open-canal network was expected to apply a total of 457 mm, present farmer applied 492 mm irrigation water; while a farmer growing maize in Kumkale village with piped-network was expected to apply 512 mm, the present farmer applied 975 mm; finally a farmer growing maize in Mahmudiye village with open-canal network was expected to apply 379 mm water, the present farmer applied 228 mm irrigation water throughout the entire growing season. Irrigation water efficiency (IWUE) values indicating the effects of irrigation water quantities on yields were calculated as 2.5 kg/da/mm for tomato culture in Kumkale; 12.3 kg/da/mm for tomato culture in Mahmudiye; 0.7 kg/da/mm for maize culture in Kumkale and 8,7 kg/da/mm for maize culture in Mahmudiye village. Relative irrigation supply (RIS) values indicating how efficiently the precipitations were used were calculated as 2.98 for tomato culture in Kumkale; 1.41 for tomato culture in Mahmudiye; 2.40 for maize culture in Kumkale and 0.85 for maize culture in Mahmudiye village.

Evaluation of minor irrigation schemes using performance indicators: case studies from South India

Food security challenge in India can be addressed to a considerable extent by improving the performance of irrigation systems. Two minor irrigation schemes in the Kozhikode district of Kerala in South India, namely, Kanniparamba and Vellannur, were assessed for their performance in terms of technical and social components. Water availability constraint in crop growth does not exist, as denoted by the high Relative Water Supply values. Irrigation delivery service in Vellannur is better, compared to Kanniparamba, when their relative irrigation supply values are taken into account. The canal system in Vellannur scheme also shows better maintenance, and hence, conveys water more effectively to the farms. Opportunity for saving water exists in the schemes through careful operation of the system and planning the water delivery by considering effective rainfall and crop water requirements. The relevance of initiating farmer participatory activities for management/distribution of the required quantity of water for crops to enable farmers to change from the practice of excess water use and for better water management is evident. This can be achieved by introducing suitable measures to institutionalize farmers’ participation under the minor irrigation schemes, which do not presently exist under the minor irrigation sector in Kerala State of India.