AbstractThis paper summarizes the present position of agricultural spray irrigation in England and Wales, providing (a) national statistics and regional information, (b) the reasons why farmers irrigate, (c) the place of agriculture in the economy, and (d) the value of irrigation. A review of the Ministry of Agriculture, Fisheries and Food irrigation surveys highlights the important crops in terms of area and volume of water used, sources of water and storage, and application methods. The predictions for the future, including the effects of climate change are reviewed with examples of how farmers, the EA, and the agricultural industry, are helping to overcome problems.
Agricultural irrigation represents the main use of global water resources. Irrigation has an impact on the environment, and scientific evidence suggests that it inevitably leads to salinization of both soil and aquifers. The effects are most pronounced under arid and semi-arid conditions. In considering the varied impacts of irrigation practices on groundwater quality, these can be classed as either direct—the direct result of applying water and accompanying agrochemicals to cropland—or indirect—the effects of irrigation abstractions on groundwater hydrogeochemistry. This paper summarizes and illustrates through paradigmatic case studies the main impacts of irrigation practices on groundwater salinity. Typically, a diverse range of groundwater salinization processes operating concomitantly at different time scales (from days to hundreds of years) is involved in agricultural irrigation. Case studies suggest that the existing paradigm for irrigated agriculture of focusing mainly on crop production increases has contributed to widespread salinization of groundwater resources. ; This study was supported by CEIMAR "Campus de Excelencia Internacional del Mar" and the projects CADESEM (Grant Number P11-RNM-8115), Junta de Andalucia Regional Government, Spain, and KARSTCLIMA (Grant Number CGL2015-71510-R) and ACUIDESAL (Grant Number CGL2015-67273-R), Spanish Ministry of Science and Technology—FEDER.
Policy regarding effluent water and reclamation aims to prevent environmental pollution while proposing an alternative water resource. Water makes up 99–99.9% of raw wastewater. Thus extracting organic and inorganic matter from water is a must. Worldwide, but especially in developed countries, great effort has been made to reuse wastewater, and it is becoming a reliable alternative source. Israel is the world leader in water reuse, allocating 85% of effluent water for agricultural irrigation. As such, it constitutes a "living laboratory" in which to study the implications of the intensive use of treated wastewater for agricultural irrigation, leading to research and legislation regarding effluent quality and regulation. Effluent produced in Israel is subject to severe regulations and standards and is considered suitable for every use except drinking water. It is mostly allocated for agricultural irrigation with no restrictions. The irrigated lands are close to natural water sources, and therefore water leaching from the fields infiltrate those sources, becoming part of the water cycle. A group of persistent and toxic nano- and micro-organic contaminants, including pharmaceutical residues, flows to water-treatment plants from hospitals, industry, agriculture and especially the domestic sector. These contaminants' chemical structure, characterized by aromatic rings and double bonds, makes them especially persistent; they are resistant to conventional biological treatment, used as a secondary treatment. As a result, the effluent that leaves the treatment plants, which is considered to be of high quality, actually contains pharmaceutical residues. After secondary and tertiary treatment, these persistent chemical residues can still be found in surface water, groundwater and agricultural products. Pharmaceutical residues in effluent allocated for agricultural irrigation are undesirable. Expansion of the monitoring system for those contaminants, improvement of the tertiary treatment, and implementation of advanced technologies for decomposition and removal of pharmaceutical contaminants are thus needed.
Increasing water scarcity is encouraging the use of unconventional water resources. In recent years, the European Union has launched numerous initiatives to promote and facilitate water reuse for agricultural irrigation. Today, the use of reclaimed water for agriculture has become an alternative, reliable and safe source of water supply and an indispensable water planning tool, especially in the area of southern Europe. However, water reuse for irrigation is currently far below its potential. Numerous barriers prevent its development and call for a detailed analysis of the different aspects affecting reclaimed water reuse, through an integrated and multidisciplinary approach.A multidisciplinary research team from Universidad Politécnica de Madrid, consisting of agronomists, hydrologists, chemists and agricultural economists, will work on the RECLAMO Project (https://blogs.upm.es/reclamo/), with the aim of providing solutions and recommendations aimed at promoting the full development and use of reclaimed water for irrigation in areas of Spain with marked water stress.For this purpose, project activities will be developed in two selected case studies (the Segura Basin, leader in water reuse in Spain and the Guadiana Basin, with success stories, but low levels of water reuse) and organised according to five axes: 1) development of a comprehensive knowledge-base covering the regulatory, technical, socio-economic and environmental aspects of reclaimed water reuse in agriculture; 2) participatory development of future scenarios exploring possible strategies, barriers and opportunities, in relation to the expansion of the use of reclaimed water for irrigation; 3) impact analysis of the strategies identified at different scales (crop, farm, (sub-)basin), through the development of an integrated modelling platform (hydrologic-agronomic-economic models); 4) Development of a roadmap and policy recommendations to achieve the full development and use of reclaimed water reuse for irrigation; 5) Dissemination of knowledge and ...
Research on water pricing is important to effectively address the water resource crisis. The agricultural industry has the greatest water-saving potential. Using Heilongjiang Province, the main grain-producing region in China, as an example, an agricultural irrigation water price was determined based on macro and micro scales, and affordable water prices for peasants were calculated. The results show a macro-agricultural irrigation water price of 1.023 yuan/m3, indicating that the current agricultural irrigation water price does not reflect the water source value. The micro-agricultural irrigation water prices for surface water and groundwater range from 0.993 to 1.008 and from 2.343 to 2.358 yuan/m3, respectively, indicating differences in cost recovery and value. The surface water prices for maize, rice, and soybeans ranged from 0.286 to 0.476, from 0.101 to 0.179, and from 0.180 to 0.307 yuan/m3, respectively, while the appropriate groundwater prices ranged from 0.317 to 0.507, from 0.131 to 0.210, and from 0.211 to 0.337 yuan/m3, respectively. The government could formulate different subsidy policies according to the actual situation and raise agricultural irrigation water prices to the full-cost level to enable the implementation of law of value.
AbstractIn recent years, more and more countries see irrigation using reclaimed water as an opportunity to secure and enhance agricultural production. Despite the benefits of water reuse, the scientific community raised several concerns and challenges for human health and the environment. This includes chemical risks. Effluents from urban wastewater treatment plants usually contain a wide range of organic chemicals. Such chemicals remaining in the water after the treatment process may cause hazards for human health, contaminate surrounding soil and water resources, and even compromise drinking water sources. Once crops on irrigated sites are exposed to chemicals, the potential transport to and accumulation in the edible parts of fruits and vegetables need to be controlled to rule out their introduction into the food chain. Finally, problems concerning the release of wastewater-borne antibiotics into the environment are starting to gain attention. For these reasons, agricultural irrigation should face more stringent quality requirements in order to minimize chemical risks. Combinations of measures reducing chemicals at the source, technical and natural water treatment processes especially to remove chemicals with persistent, bioaccumulative and toxic (PBT), or persistent, mobile and toxic (PMT) properties, good agricultural practices, and supplementary preventive measures (e.g. knowledge transfer to the stakeholders involved) will be necessary to bring about and ensure safe irrigation in the future. While internationally many regulations and guidelines for water reuse have successfully been implemented, questions remain whether the current knowledge regarding chemical risks is sufficiently considered in the regulatory context. The introduction of a new regulation for water reuse, as attempted in the European Union, poses a good opportunity to better take chemicals risks into account.
The United Nations (UN) has identified 17 Sustainable Development Goals (SDGs) to tackle major barriers to sustainable development by 2030. Achieving these goals will rely on the contribution of all nations and require balancing trade-offs among different sectors. Water and food insecurity have long been the two major challenges facing China. To address these challenges and achieve the SDGs, China needs to safeguard its agricultural irrigation and water conservancy projects. Although China is making efforts to transition its agricultural development to a sustainable trajectory by promoting water-saving irrigation, a number of issues are emerging, both with policy reforms and technological innovations. Through synthesizing the historical development of agriculture and its relationship with policy and political regimes, this paper identifies four major issues that are challenging the sustainability transformation of China&rsquo ; s agricultural irrigation system and water conservancy projects: (1) problems with financial policy coordination between central and local governments ; (2) the lack of incentives for farmers to construct and maintain irrigation infrastructure ; (3) conflicts between decentralized operation of land and benefits from shared irrigation infrastructure ; and (4) deterioration of small-scale irrigation infrastructure calls for action. In addressing these challenges, policy changes are required: government financial accountability at all levels needs to be clarified ; subsidies need to be raised for the construction and management of small-scale irrigation and water conservancy projects ; local non-profit organizations need to be established to enhance co-management between farmers and government.
The reuse of treated municipal wastewater (herein referred to as reclaimed water) in agricultural irrigation (RWAI) as a means to alleviate water scarcity is gaining increasing policy attention, particularly in areas where water demand mitigation measures have proved insufficient. However, reclaimed water reuse in practice is lagging behind policy ambition, with <2.5% of it reused in a European context. A key barrier identified as limiting its full valorisation is concern over its impact on human and environmental health. To address this concern, and to meet further objectives including achieving parity between current reclaimed water reuse guidelines operational in various Member States, the European Commission has proposed a regulation which identifies minimum quality requirements (MQR) for a range of microbiological and physico-chemical parameters but the inclusion of compounds of emerging concern (CECs) in terms of the determination of quality standards (QS) is missing. This paper reviews the existing pertinent EU legislation in terms of identifying the need for CEC QS for RWAI, considering the scope and remit of on-going pan-European chemicals prioritisation schemes. It also evaluates opportunities to link in with the existing EQS derivation methodology under the EU WFD to address all protection targets in the environmental compartments exposed via potential pathways of RWAI. Finally, it identifies the main data gaps and research needs for terrestrial ecosystems, the removal efficiency of CECs by WWTPs and transformation products generated during the wastewater reuse cycle.
