Water Use In Irrigated Agriculture Research Articles

Effect of climate change-induced water-deficit stress on long-term rice yield.

The water requirements of crops should be investigated to improve the efficiency of water use in irrigated agriculture. The main objective of the study was to assess the effects of water deficit stress on rice yields throughout the major cropping seasons. We analyzed rice yield data from field experiments in Taiwan over the period 1925-2019 to evaluate the effects of water-deficit stress on the yield of 12 rice cultivars. Weather data, including air temperatures, humidity, wind speed, sunshine duration, and rainfall were used to compute the temporal trends of reference evapotranspiration and crop water status (CWS) during rice growth stages. A negative CWS value indicates that the crop is water deficient, and a smaller value represents a lower water level (greater water-deficit stress) in crop growth. The CWS on rice growth under the initial, crop development, reproductive, and maturity stages declined by 96.9, 58.9, 24.7, and 198.6 mm in the cool cropping season and declined by 63.7, 18.1, 8.6, and 3.8 mm in the warm cropping season during the 95 years. The decreasing trends in the CWSs were used to represent the increases in water-deficit stress. The total yield change related to water-deficit stress on the cultivars from 1925-1944, 1945-1983, and 1996-2019 under the initial, crop development, reproductive, and maturity stages are -56.1 to 37.0, -77.5 to -12.3, 11.2 to 19.8, and -146.4 to 39.1 kg ha-1 in the cool cropping season and -16.5 to 8.2, -12.9 to 8.1, -2.3 to 9.0, and -9.3 to 8.0 in the warm cropping season, respectively. Our results suggest that CWS may be a determining factor for rice to thrive during the developmental stage, but not the reproductive stage. In addition, the effect of water-deficit stress has increasingly affected the growth of rice in recent years.

Fully Distributed Water Balance Modelling in Large Agricultural Areas—The Pinios River Basin (Greece) Case Study

Robust assessments of variations in freshwater availability are essential for current and future water resource management in the Pinios River Basin (PRB), which is one of the most productive basins of Greece in terms of agriculture. To support sustainable water resources management in the PRB, we set up and calibrated the mGROWA hydrological model at a high spatial (100 m) and temporal (daily) resolution for the period 1971–2000, with particular attention given to deriving crop-specific irrigation requirements. We developed and implemented a comprehensive methodological framework to overcome data scarcity constraints in the PRB, thus enabling the derivation of high-resolution spatially continuous estimates of many input variables required for the mGROWA model. We generated estimates of spatiotemporal variations in the water balance components actual evapotranspiration, irrigation requirements, total runoff, and groundwater recharge for the PRB. In addition, through the calculation of indices, such as the potential irrigation to groundwater recharge ratio (PIQR), we demonstrate a way to identify potential unsustainable water use in irrigated agriculture. The established mGROWA model can be used both as a hydrological reference model providing continuous decision support for water resources management, focusing on irrigation water use, and a basis for climate impact studies for the PRB.

Deep learning for proximal soil sensor development towards smart irrigation

Excessive agricultural water consumption threatens safe access of billions of people to potable water. Smart irrigation systems offer more efficient water use in irrigated agriculture. Determining irrigation requirements of various soil texture classes in production fields requires more sophisticated sensing technologies such as deep learning. This study has proposed a proximal sensing system by means of using a color camera towards smart irrigation based on computer vision and deep learning to identify water requirements of three soil texture classes under different illumination conditions. An imaging station was composed to reduce the workload in obtaining training images required for training deep convolutional neural network models. Five deep learning architectures were employed to identify texture-water classes: AlexNet, GoogleNet, ResNet, VGG16, and SqueezeNet. Those models were experimented with and investigated to determine the best models in terms of detection performance and speed. By using cross-validation rules, approximately 12,214 images were studied individually for the purpose of training and testing. The AlexNet model outperformed the other deep learning models with an F1-score of 0.9973 in identifying twelve soil texture-water classes. GoogleNet and ResNet displayed the fastest detection speeds with an average processing time of 16.92 ms. The findings obtained from this study have indicated that deep learning bears a great potential in determining irrigation requirements of production fields under varying conditions

Development of irrigation based on various business payment systems

As the result of the changes that took place in the Russian economy in the 90s, interfarm reclamation systems remained in state ownership, and reclamation lands and intra-farm irrigation systems were transferred to private ownership. For fixed assets managed by budget organizations that pump water for irrigation, depreciation deductions are not provided by the current legislation, and state subsidies cover only a small part of the necessary restoration work. The study uses international practices in the field of paid water use in irrigated agriculture, the regulatory and methodological framework adopted on the territory of the Russian Federation, data received from regional state organizations for land reclamation and agriculture, materials, data from Russian Federal State Statistics Service and the Ministry of Agriculture of the Russian Federation, the work of Russian and foreign scientists and practitioners. The article explains the pricing of water supply for irrigation, creation of funds (financial resources) in the accounts of plumbing organizations to update their fixed assets, upgrading irrigation systems, having the physical deterioration of more than 70%.

Problems of introducing a system of paid water use in irrigated agriculture in water-deficient regions of Russia (on the example of the Rostov region)

In the face of climate change, regulation of water use is essential. On the example of the Rostov region, the necessity of introducing paid water for agricultural lands was considered. Rostov region is one of the largest producers of agricultural products, including wheat and sunflower. At the same time, this territory belongs to arid territories and needs irrigation of agricultural land. The Lower Don basin on the territory of the Rostov region includes the territory from the Tsimlyansk reservoir to the river mouth. The quality of water resources and river runoff of large waterways in the Don region is largely determined by small rivers, whose environmental problems are also associated with a high anthropogenic load, indicating intense economic activity. The article discusses the possibilities of using the system of payment for water use for agriculture. It is shown that the introduction of a system of tariffs for irrigation water, as well as the modernization of existing legal norms, will reduce the anthropogenic load on the ecosystem. The systemic regulation of water use should ultimately lead to the modernization of the system of irrigation canals and the cleaning of small rivers in the region.

Effective and rational use of irrigation water in the conditions of the republic of Karakalpakstan

The lack of water that has been repeated in recent years dictates the requirements of a strict regime of water conservation and economical use of water. Understanding the need for strict water conservation and the fight against unproductive water losses must be started with the producers of agricultural products, i.e., from farms, as rational water use and water conservation at the field level could save a significant amount of irrigation water. The article reflects the current state of water use in irrigated agriculture in the Republic of Karakalpakstan. The main, inter-farm, and intra-farm canals have been studied in detail, and the mode and efficiency of their work have been assessed. The obtained results of the conducted field research works on irrigation technologies are presented. Suggestions on the choice of water-saving irrigation technologies are given, as well as recommendations on the effective use of irrigation water in the non-growing season.

Incorporating water loss from water storage and conveyance into blue water footprint of irrigated sugarcane: A case study of Savannah Sugar Irrigation District, Nigeria.

Assessing the impacts of irrigation on water resources is crucial to effectively understanding how water is withdrawn for irrigation purposes. Consequently, the extraction of water from rivers, reservoirs and aquifers for irrigation purposes usually exceeds the net requirement for irrigation due to water lost in its delivery from source to the crop fields. In this this study, we have proposed a model for incorporating seasonal water loss from storage reservoir and conveyance canal into the crop water footprint of irrigated sugarcane. By taking into consideration the duration of seasonal irrigation water release for sugarcane production, we present a method for allocation of blue water footprint using savannah sugar irrigation district as case study. Results have shown that significant volume of water is evaporated seasonally due to irrigation of sugarcane, despite the introduction of an allocation factor to account of evaporation loss to irrigation. For the study period of 2007-2017, the reservoir is the main contributor to water loss by evaporation, it accounts for an average seasonal water loss of 1.1×108m3, followed by evapotranspiration from the crop field 0.26×108m3 and then seepage and evaporation losses from the canal 7.9×104m3. The average seasonal blue water footprint of sugarcane for the period considered is 877m3/ton which exceeds the global average 209m3/ton. Plans to expand hectares of cultivated land by the company to boost sugarcane productivity, coupled with the ongoing effort to incorporate hydroelectric power plant to the existing dam to augment electric power supply in the district, will greatly influence the availability water resources in the region. This study highlighted the need for a comprehensive evaluation of water use in irrigated agriculture and may serve as an indicator for optimizing future objectives and strategies associated with water resource planning globally.

WATER EFFICIENCY INDICATORS FOR EVALUATION OF INSTITUTIONAL TRANSFORMATIONS IN IRRIGATION MANAGEMENT

The modern problems of irrigation sector and need of its reforms are presented as well as the importance of evaluation of reforms results via system of indicators that characterized efficiency of water use and effectiveness of water management. For this purpose, the methods of system analysis are used and the main economic and ecological factors influencing the efficiency of water use are determined. Based on the results of the system analysis an indicative assessment proposed for the following three spatial levels: for assessment of the efficiency of the irrigation sector at the national level; evaluation of water management efficiency at the level of main infrastructure and; at the level of non-state irrigation network. The efficiency of water use in irrigated agriculture at the national level is calculated as the added value in agriculture sector related to the amount of water taken for agricultural purpose. This indicator shows general productivity of water use in irrigated agriculture. Groups of ecological and economic indicators that proposed for assessing the efficiency of water use on the level of the main irrigation infrastructure allow to assess the quality of irrigation service under existing management model. For evaluation of efficiency of water use and management at the level of water users’ organizations and individual farms the following economic indicators are selected: land productivity; water productivity; irrigation area; volume of water used for irrigation; costs of irrigation and amount of production. The soil fertility and ecological state of the irrigated lands proposed as a main ecological indicator. In addition to the economic and ecological indicators the number of organizational and technological factors that provides reliability of water supply to the fields and show a effectiveness of water management should be evaluated also. The proposed integrated system of indicators can be used to evaluate the state of water use and water management in irrigated agriculture, as well as to assess the results of institutional reforms of the sector that approved by the state strategic documents.

Farmers’ Attitudes Toward Recycled Water Use in Irrigated Agriculture

This study aims to investigate whether farmers are willing to use recycled water for irrigation purposes. It attempts to analyze the attitudinal, socio-demographics and environmental factors that affect a potential user’s acceptance for wastewater reuse. A primary research designed in order to elicit farmers’ preferences and a statistical analysis applied to analyze the relationships among the variables influence their attitudes. The results were obtained from data collected through 302 questionnaires that were answered by the farmers in Nestos catchment, Greece. The research findings might usefully assist policy-makers and planners in the implementation of strategy in water management sector. Farmers’ awareness about the recycling water and their level of acceptance to use it might constitute incoming parameters, on which the decisions in agriculture water planning could be based. Moreover, the identification of factors influencing stakeholders’ acceptance provide the underpinnings for success in any recycling project.
 
 
 Keywords: public perceptions, behavior analysis, water recycling, integrated water resources management, agriculture water management

GlobWat – a global water balance model to assess water use in irrigated agriculture

Abstract. GlobWat is a freely distributed, global soil water balance model that is used by the Food and Agriculture Organization (FAO) to assess water use in irrigated agriculture, the main factor behind scarcity of freshwater in an increasing number of regions. The model is based on spatially distributed high-resolution data sets that are consistent at global level and calibrated against values for internal renewable water resources, as published in AQUASTAT, the FAO's global information system on water and agriculture. Validation of the model is done against mean annual river basin outflows. The water balance is calculated in two steps: first a "vertical" water balance is calculated that includes evaporation from in situ rainfall ("green" water) and incremental evaporation from irrigated crops. In a second stage, a "horizontal" water balance is calculated to determine discharges from river (sub-)basins, taking into account incremental evaporation from irrigation, open water and wetlands ("blue" water). The paper describes the methodology, input and output data, calibration and validation of the model. The model results are finally compared with other global water balance models to assess levels of accuracy and validity.

Incentives to adopt irrigation water saving measures for wetlands preservation: An integrated basin scale analysis

Summary Preserving natural wetlands is a growing challenge as the world faces increased demand for water. Drought, climate change and growing demands by users aggravate the issue. The conflict between irrigated agriculture and wetland services presents a classic case of competition. This paper examines an institutional mechanism that offers an incentive to farmers to adopt water conservation measures, which in turn could reduce overall water use in irrigated agriculture within a selected basin. Reduced water demands could provide the additional water needed for wetland preservation. We present an analytical empirical model implemented through the development of an integrated basin framework, in which least-cost measures for securing environmental flows to sustain wetlands are examined for the Zayandeh-Rud River Basin of central Iran. To test this idea, two policies – one with and one without an incentive – are analyzed: (a) reduced agricultural diversions without a water conservation subsidy, and (b) reduced agricultural diversions with a water conservation subsidy. The policies are evaluated against a background of two alternative water supply scenarios over a 10-year period. Results reveal that a water conservation subsidy can provide incentives for farmers to shift out of flood irrigation and bring more land into production by adopting water-saving irrigation technologies. The policy increases crop yields, raises profitability of farming, and increases the shadow price of water. Although the conservation subsidy policy incurs a financial cost to the taxpayer, it could be politically and economically attractive for both irrigators and environmental stakeholders. Results open the door for further examination of policy measures to preserve wetlands.

Simulation of soil water in space and time using an agro-hydrological model and remote sensing techniques

Complete knowledge of all components of the water balance is essential to optimize water use in irrigated agriculture. However, most water balance components are very difficult to measure in terms of the required time interval and due to the complexity of the processes. An unsaturated zone model is a useful tool for predicting the effects of agricultural management on crop water use and can be used to optimize agricultural practices in view of minimizing the agricultural water use. For the irrigated areas in Minqin County of northwest China, the physically based one-dimensional agro-hydrological model SWAP (Soil, Water, Atmosphere and Plant) for water movement and crop growth was applied to reveal all the components of the water balance at multiple sites. This model has a varying level of abstraction referring to simulated processes in time and space. A combination of field, meteorological and aerial data was used as input to the model. Inverse modeling of evapotranspiration (ET) fluxes was followed to calibrate the soil hydraulic functions by using the parameter estimation package PEST. Surface Energy Balance System (SEBS) was used to estimate actual ET fluxes from NOAA AVHRR satellite images. Simulations were carried out for 15 different sites in Minqin County by using wheat ( Triticum aestivum L.) as a test crop, but only three sites were selected for model calibration and evaluation. The period of simulation for the whole wheat growing season was from 1 April 2004 to 30 July 2004 and detailed analyses were performed for all sites. SWAP simulated soil water dynamics well and the distributed SWAP model is a useful tool to analyze all water balance components.

Estimation of excess water use in irrigated agriculture: A Data Envelopment Analysis approach

Overpumping of the Ogallala Aquifer in western Kansas due to expansion of irrigated agriculture is believed to have resulted in reductions in water storage volumes and drops in the water table in several regions. It is widely agreed upon that water demand should be reduced through increases in water use efficiency to make irrigated agriculture in the region more sustainable. The existence of several terms related to the efficiency with which irrigation water is used, however, may be hampering the development of appropriate water conservation policies. In particular, while there has been an emphasis on increasing water application efficiencies of irrigation systems, little empirical testing has been done on the effects of such changes on water use efficiency. The primary purpose of this paper is to determine the impacts of irrigation system type, as well as other variables, on irrigation water use efficiency for a sample of 43 irrigators in western Kansas between 1992 and 1999. The use of panel data permits both cross-sectional and temporal comparisons, with the latter being particularly relevant as there was a large-scale shift in irrigation system types during the study period. The method used to quantify water use efficiency or, more specifically, excess irrigation water used, is Data Envelopment Analysis (DEA). Based upon linear programming techniques, DEA creates a “best practice” production frontier based on the irrigators that produced their level of crop output with the least amount of water. What is implied is that those who are able to produce their output levels using the least amount of water are better water managers. These farms then serve as benchmarks against which the water use inefficiency of all other irrigators, or amount of “excess water” used, can be measured. The relationship between the magnitude of irrigation water excess, or reduction potentials, and irrigation system type and a number of other farm characteristics are then determined. A major finding of the study is that there is only a weak relationship between irrigation system type and the level of excess irrigation water used. In particular, flood irrigation systems are not clearly inefficient and management may play a significant role in the levels of water use efficiency that can be reached. Additional results indicate positive relationships between water excess and age of farmer, negative relationships between water excess and farm size, and differences in water excesses between farms located in different groundwater management districts.

The resource potential of in-situ shallow ground water use in irrigated agriculture: a review

Shallow ground water is a resource that is routinely overlooked when water management alternatives are being considered in irrigated agriculture. Even though it has the potential to provide significant quantities of water for crop use under the proper conditions and management. Crop water use from shallow groundwater is affected by soil water flux, crop rooting characteristics, crop salt tolerance, presence of a drainage system, and irrigation system type and management. This paper reviews these factors in detail and presents data quantifying crop use from shallow ground, and describes the existing state of the art with regard to crop management in the presence of shallow ground water. The existing data are used to determine whether in-situ crop water use from shallow ground water is suitable for a given situation. The suggested methodology uses ratios of ground water electrical conductivity to the Maas–Hoffman yield loss threshold values, the day to plant maturity relative to plant growth period, and the maximum rooting depth relative to the nearly saturated zone. The review demonstrates that for in-situ use to be feasible there has to be good quality ground water relative to crop salt tolerance available for an extended period of time. Shallow ground water availability is one area that can be managed to some extent. Crop selection will be the primary determinant in the other ratios.

Satellite remote sensing to support management of irrigation systems: concepts and approaches

AbstractRemote sensing techniques are becoming powerful tools for efficient management of irrigation systems in large irrigated areas. The objectives of management of irrigation systems, although they vary widely, may be defined as high crop productivity per unit land per unit applied water with equity in distribution. Some of the key elements of irrigation system management are: (i) performance monitoring and evaluation, (ii) diagnostic appraisal, (iii) action research, and (iv) farmers' participation. The objective of this paper is to present the state of the art on applications of satellite remote sensing that support management of irrigation systems and to identify emerging approaches that focus on future directions of research which may pave the way to operationalise the remote sensing techniques in practice. Firstly, a brief review on different approaches being utilized for management of irrigation systems is dealt with. Subsequently, the present status of remote sensing applications in irrigated agriculture is reviewed. The paper also presents future perspectives of remote sensing applications in determining hydrological variables and quantifying irrigation system performance indicators for better management of water use in irrigated agriculture. Copyright © 2002 John Wiley & Sons, Ltd.

Improvement of Field Water Distribution and Irrigation Techniques: The Southeastern Anatolia Project-GAP

ABSTRACT The Southeastern Anatolia Project-GAP is an integrated regional development project implemented in southeast Turkey. The project cows all development-related sectors such as agriculture, industry, health care, education. tourism, transportation, and telecommunications. Water resources development is one most important component of the project. Rational use of water is the goal in every aspect of development, be it hydropower, irrigation, or flood control. To complement the efforts to optimize water use in irrigated agriculture, a project has been carried out in regard to on-farm equipment and management of water. This paper describes several equipment and management combinations, applied to a very large irrigation area. ranging from gravity to sprinkler irrigation, and from upstream to downstream control of water. Five different applications are analyzed in this study along with their technical, economic, and operational merits and disadvantages. The project area is selected in the Sanliurfa-Harr...

Irrigation Water Distribution along Branch Canals in Egypt: Economic Effects

Over 75% of the world's irrigated lands are found in developing countries.' Given the need to expand agricultural output to meet the growing food demands in these countries and elsewhere in the world, it is apparent that improving the efficiency of irrigated agricultural systems is an important component of agricultural development strategies. Future world food needs depend on means to improve the efficiency of water use in irrigated agriculture. Analysts of irrigated agricultural systems around the world have observed a problem common to most, if not all, irrigation projects in which the amount of water for the available land is limited. The problem is to achieve a more equitable and efficient system of allocating water among lands, crops, or users. Often, a farmer's position relative to the head of a common branch canal determines his access to water; farmers near the start of the canal may receive ample water, but those at the distant reaches of the same canal are often poorly served. In his review of the need for economic analysis of irrigation, Taylor identifies a number of studies concerned with the allocation of