Irrigation Advisory Service Research Articles

Combination of typical meteorological year with regulated deficit irrigation to improve the profitability of garlic growing in central spain

This paper shows an adaptation of the typical meteorological year (TMY) method for irrigation schedule forecasting in combination with the optimized regulated deficit irrigation (ORDI) strategy to increase the water productivity of crops and their profitability. This methodology has been simulated using the MOPECO model on garlic (Mulvico cultivar) under deficit irrigation conditions in Castilla-La Mancha (Spain), although it may be useful for other crops and areas in the world. Experimental data from a three-year field test were collected for the calibration (2001) and validation (2000 and 2002) processes. Key objectives of this research were: (1) to adapt the TMY methodology for irrigation schedule forecasting; (2) to calibrate and validate the parameters required for simulating garlic using the MOPECO model; and (3) to determine the most suitable irrigation strategy for the Protected Geographical Indication “Ajo morado de Las Pedroñeras” considering four deficit targets (100, 90, 80, and 70% of maximum evapotranspiration) using ORDI and TMY methodologies. The growing-degree-days for the whole growth cycle are approximately 2044°C, while the calibrated crop yield response (Ky) values for the growth stages proposed by FAO-56 are 0.45 (vegetative period), 0.75 (yield formation), and 0.3 (ripening). The combination of TMY with ORDI may increase yield by 3–9% and gross margin by up to 59% compared to a constant deficit irrigation strategy. When water deficit conditions are present, it is of interest to guarantee nascence but also favour the bulb formation stages as much as possible, inducing water stress during the vegetative development stage. Under the current harvest sale price scenario (1.15€kg−1), this crop reaches a gross margin of around 3400€ha−1 for maximum yield (11,200kgha). Thus, irrigation advisory services can supply important information to farmers that may be translated to higher profitability and crop yield at the farm and/or basin scale.

Solid-Set Sprinkler Irrigation Controllers Driven by Simulation Models: Opportunities and Bottlenecks

Farmers continue to show great differences in irrigation water use, even for a given location and crop. Irrigation advisory services have narrowed the gap between scientific knowledge and on-farm scheduling, but their success has been limited. The performance of sprinkler irrigation is greatly affected by factors such as wind speed, whose short-time variability requires tactical adjustments of the irrigation schedule. Mounting energy costs often require the consideration of interday and intraday tariff evolution. Opportunities have arisen that allow these challenges to be addressed through irrigation controllers guided by irrigation and crop simulation models. Remote control systems are often installed in collective pressurized irrigation networks. Agrometeorological information networks are available in regions worldwide. Water users’ associations use specialized databases for water management. Different configurations of irrigation controllers based on simulation models can develop, continuously update, and execute irrigation schedules aiming at maximizing irrigation adequacy and water productivity. Bottlenecks requiring action in the fields of research, development, and innovation are analyzed, with the goal of establishing agendas leading to the implementation and commercial deployment of advanced controllers for solid-set irrigation.

Evaluation of furrow irrigation practices in Fergana Valley of Uzbekistan

The performance of furrow irrigation systems in terms of application efficiency, runoff ratio, and water requirement efficiency were evaluated at nine different sites within the Provinces of Fergana (6 sites) and Andijon (3 sites) in Uzbekistan. A total of 46 irrigation events were evaluated during the year 2009, whereas only a total of 8 irrigation events (at 3 sites) were evaluated during the year 2010. Most of the selected fields have slopes greater than 0.005; hence, the average runoff volume from these fields was 39% of the total volume of water applied to the fields, indicating problems with selection of appropriate furrow flow rates under the given set of field conditions. For several fields, the seasonal volume of water applied was significantly different than the irrigation norms specified for the site. Though some of the farmers followed the irrigation advisory service on when to irrigate, there was a large mismatch between the volume of water applied and the volume of water deficit within the crop root zone. Reliability, in terms of magnitude and duration of flow rate received at the fields, was a major issue at all the sites. Considerable fluctuations were observed in the flow rates received at all the field sites during each irrigation event. In addition, the average flow rate received at the field sites varied considerably between irrigation events making it difficult for farmers to manage irrigation water. Farmers that had high watertable (less than 100cm from the ground surface) still applied large volumes of water, resulting in low application efficiency. Several recommendations for improving the performance of furrow irrigation systems in Uzbekistan are provided.

Assessment of the Irrigation Advisory Services’ Recommendations and Farmers’ Irrigation Management: A Case Study in Southern Spain

The Local Irrigation Advisory Services (LIAS) carry out essential work to achieve an efficient use of irrigation water at field and irrigation scheme level, which is crucial in Mediterranean irrigation systems. However, it is unusual to find agronomic and economic assessments of LIAS advice. In this work, the LIAS operating in the Genil–Cabra Irrigation Scheme (southern Spain) was evaluated during the first 5 years of its advice. Acceptance by farmers of the LIAS recommendations was evaluated by using agronomic indicators, such as ARIS (Annual Relative Irrigation Supply). ARISLIAS (actual irrigation applied v. recommendation of LIAS) with values ranging from about 0.23 for wheat and sunflower, and 0.94 for maize, also detecting a high variability between farmers, which indicated a scant acceptance of the LIAS recommendations. The economic evaluation of irrigation was made through two economic indicators, Irrigation Water Productivity (IWP) and Irrigation Water Benefit (IWB). IWP values varied significantly between different crops: around 0.23 € m−3 in wheat, sunflower and maize, about 0.53 € m−3 in cotton and sugar beet, and values higher than 2.0 € m−3 in garlic, for optimal irrigation schedules. For IWB, trends were similar, emphasizing the low IWB values in wheat and sunflower (average values of 0.06 and 0.13 € m−3, respectively). Consideration of these economic indicators by LIAS could not only help to obtain more suitable and economically profitable irrigation schedules, but also contribute towards a greater acceptance of advisory services by farmers, by shifting the emphasis from maximizing production to maximizing irrigation profitability.

Improving on-farm water management through an irrigation scheduling service

Irrigation scheduling services (ISS) provide farmers with recommendations on timing and amount of irrigation, thus contributing to improving on-farm water management. There are wide variations in the level of services, from providing regional water use guidelines to local, on-farm advisory services. An ISS (ISS-ITAP) was created in 1988 in Albacete, Central Spain, a province encompassing 100,000 ha which are irrigated mostly with groundwater. The ISS-ITAP first offered general information on crop water requirements (ET), and after 1994 field-specific scheduling services were provided to growers. By 2005 the ISS-ITAP had expanded its services to over 33,500 ha, corresponding to about 30% of the irrigable area. The evolution of irrigation performance in a number of individual farms was followed over 10 years, and it was found that the proportion of fields which were adequately irrigated increased from 50 to over 70% in that period. Meanwhile, the proportion of deficit-irrigated fields declined from 20 to 10%, while the proportion of over-irrigated fields which also had initially decreased from 20 to 10%, went back to 20% at the end of the study period. To assess the benefits and costs of the ISS-ITAP, a comparison of the yields achieved in the scheduled farms against those obtained in the rest of the province was carried out. When the Service was evaluated in economic terms, using information from 2003, the pay-back was 2 years and the internal rate of return was 59.1%, highlighting the high returns on the public funds invested by ISS-ITAP to provide irrigation advisory service to growers in the Albacete province.

Operational Monitoring of Daily Crop Water Requirements at the Regional Scale with Time Series of Satellite Data

This work presents a simple, cost-effective, and operational approach to monitor crop water requirements at the regional scale for water management and monitoring purposes. The recommended Food and Agricultural Organization of the United Nations methodology (FAO-56) calculates crop evapotranspiration using crop-specific coefficients ( Kc ) , which vary according to the crop type, health, and phenological stage. This approach, though widely applied for irrigation planning, cannot always match the appropriate crop coefficient with the actual crop phenological stage and health condition, especially in anomalous situations. Previous research demonstrated that crop coefficients and spectral vegetation indexes are correlated. Recent studies have used this relationship with high-resolution satellite data from different sensors to provide information to irrigation advisory services. However, high-resolution data are not feasible for an operational and routine monitoring of water consumption and needs. This paper ...

Irrigation management from space: Towards user-friendly products

Irrigation Advisory Services (IAS) are the natural management instruments to achieve a better efficiency in the use of water for irrigation. IAS provide the farmers with irrigation scheduling information, based on crop water requirements for different crops, and thus, help farmers to optimise production and cost-effectiveness. Current IAS rely on labour- and cost-intensive field work, yet are unable to cover each plot in large areas at regular short time intervals. Earth observation (EO) is naturally destined to fill this gap. It allows for efficiently monitoring crop water requirements and related parameters within each field in extended areas. The incorporation of IT in the generation and distribution of information makes that information easily available to IAS and to its associated farmers in a personalised way. Farmers can opt to receive a wide variety of products, tailored to their needs and infrastructure, ranging from simple irrigation scheduling recommendation (irrigation volume, time) to colour-coded images (providing quick intuitive information on the crop vigour within their plots), both on PC and/or mobile phones. This work is based on the project DEMETER (DEMonstration of Earth observation TEchnologies in Routine irrigation advisory services), which assesses and demonstrates the EO- and IT-induced improvements in IAS day-to-day operations. This paper describes the methodology and discusses examples of products.

Improving water management: The irrigation advisory service of Castilla-La Mancha (Spain)

This work presents the main methodological aspects and results obtained from the activity of the Irrigation Advisory Service for Farmers (SIAR) of Castilla-La Mancha, Spain. Castilla-La Mancha is a broad semi-arid region, with a total area of 8 million ha and an irrigable area of more an 475,000 ha. Most of these irrigated areas (at least 60%) present serious problems of water scarcity, and are in need of improvement in the use of irrigation water. SIAR upgrades farmers’ capacities and awareness, thus minimizing the negative environmental impacts of irrigation, decreasing the production costs and contributing to the sustainability of irrigated agriculture in the area. Approximately, 25% of the irrigated area is advised, representing 499 collaborator farmers within an area of ca. 100,000 ha. Water-scarce areas are where the SIAR advice is more closely followed by the farmers and irrigation performance indicators are highest. The total estimated cost for the service is of about €3 ha −1 yr −1. A team of field technicians forms the core of SIAR. The team is assembled via a cooperation agreement between the University of Castilla-La Mancha and the Regional Government. Among the results and conclusions obtained, the most important is the improvement of water use. However, technical, social and economic limitations are relevant, and constitute a handicap to achieve the objectives of the advisory service.

Participatory groundwater management in Jordan: Development and analysis of options

Groundwater over-exploitation has been on the rise in Jordan. Competing demands have grown in the face of perennial water shortages, a situation which has been exacerbated by drought conditions in the past decade. This paper reports findings of a project in which management options to address over-exploitation were developed for one of Jordan’s principal aquifer systems, the Amman-Zarqa Basin. Options for addressing the situation were developed through a participatory approach that involved government officials and various public and private sector interest groups. Particular efforts were made to involve well irrigators, who are likely to be heavily impacted by the changes required to reduce groundwater pumping to a sustainable level. With information obtained from a rapid appraisal survey as well as from interviews with farmers, community groups, government officials, and technical experts, an extensive set of options was identified for evaluation. Based on integrated hydrogeologic, social, and economic analysis, five complementary management options were recommended for implementation. These included the establishment of an Irrigation Advisory Service, buying out farm wells, placing firm limits on well abstraction and irrigated crop areas, exchanging treated wastewater for groundwater, and measures to increase the efficiency of municipal and industrial water use. Various combinations and levels of these options were grouped in scenarios, representing possible implementation strategies. The scenarios were designed to assist decision makers, well owners and other stakeholders in moving gradually towards a sustainable abstraction regime. Social and economic aspects of each option and scenario were analyzed and presented to stakeholders, together with a summary of legal, institutional and environmental ramifications. Combining scientific analysis with a participatory approach in the Amman Zarqa Basin groundwater management was devised as a prototype to be used in the management of other groundwater basins in Jordan. This participatory management approach would also be useful in other parts of the world that are experiencing similar groundwater over-exploitation problems.

Monitoring irrigation water use by combining Irrigation Advisory Service, and remotely sensed data with a geographic information system

The transformation of dry lands into irrigated fields using groundwater resources has been the key to agricultural development in a large number of countries. Particularly in arid and semiarid areas, this transformation needs to take into account the limited water resources available. It is therefore, necessary to increase water application efficiency by modernising irrigation systems as well as continuously monitoring the irrigated areas in order to regulate the volume of irrigation water used. In this paper, we present tools based on Irrigation Advisory Service (IAS) and remotely sensed data combined with geographic information systems (GIS) which assist in this kind of monitoring, especially for large areas. The identification of crops in areas with small fields requires high spatial resolution satellite images. The classification criterion is based on the different temporal evolution of different crops. The crop development is described by means of the normalised difference vegetation index (NDVI). Crops belonging to the same class are assumed to have similar water requirements. We define a new concept, the hydrological management unit (HMU) which includes all the fields which use water jointly. Their spatial location is obtained from the digital rural cadaster (DRC), a vectorial map which delimits each field. The Irrigation Advisory Service of the area determines the water requirements of each crop and estimates the volume of irrigation water actually used. By introducing this information into a GIS, we can quantify the spatial and temporal distribution of water extractions. The regulation of these extractions is the key to sustainability in aquifer case studies.

Improvement of irrigation management towards the sustainable use of groundwater in Castilla-La Mancha, Spain

The great expansion of irrigated lands using groundwater has often caused the exploitation of aquifer reserves beyond their recharge capacity. The development of management tools which can harmonize resource exploitation with reserve sustainability is the objective of an interesting experience being accomplished in the aquifer 08.29 in Mancha Oriental, Spain. This paper offers a summary of this ongoing project (GESMO), pointing out the specific role of the Irrigation Advisory Service. The general objective of the project is to create an integrated and integral management system of the aquifer as well as to prepare appropriate techniques for its adequate exploitation. Integral management means that both supply and demand management are considered, including the socio-economic and environmental perspectives. The concept of integrated management implies that the process must involve the majority of economic and social agents affected. Management is founded on a Decision Support System (DSS) which takes into consideration different possible options. The DSS must contemplate the impacts on the environment, mainly the aquifer reserve losses and the increase of nitrates concentration in groundwater. The project directly affects more than 5000 agricultural users, irrigating about 100 000 ha with the aquifer water resources, as well as the whole population living in this region. Results of this project, including irrigation technologies developed may be useful for other areas in the Mediterranean Basin where similar cases occur.

Evaluation of proposed mesqa improvements

Irrigated agriculture has beenpractised in Egypt for thousands of years. Manyprojects have been implemented and new projects arestill needed to improve the existing irrigationnetworks to increase the agricultural productivity aswell as the area of cultivable land. Recently theMinistry of Public Works and Water Resources (MPWWR)in Egypt started the Irrigation Improvement Project(IIP) with the objective to increase the productionfrom the existing agricultural land. To achieve thisobjective IIP proposed the redesign of main and branchcanals, the improvement or replacement of existingtertiary canals (mesqas) and the establishment ofWater Users Associations (WUA's). IIP emphasizes thatfor an optimal effect of the proposed improvements achange from rotational supply to continuous supply,from upstream flow control to downstream flow controland from the existing Agricultural Extension Serviceto a new Irrigation Advisory Service (IAS) isnecessary. This paper mainly focuses on the proposedimprovements at mesqa level for the Bahr El Saidiarea, which is representative for the irrigation areasunder IIP. The aspects presented are:– description of the improvements and their effecton the irrigation practice;– review, evaluation and refinement of three alternatives for mesqa improvement and appraisal from management, operation and social point of view;– hydrodynamic modelling to assess the hydraulicperformance of the three alternatives.