Subscribe free to our newsletters via your
  Energy News  




Subscribe free to our newsletters via your




















FARM NEWS
Global use of wastewater to irrigate agriculture at least 50 percent greater than thought
by Staff Writers
Colombo, Sri Lanka (SPX) Jul 07, 2017


illustration only

The use of untreated wastewater from cities to irrigate crops downstream is 50 percent more widespread than previously thought, according to a new study published this week in the journal Environmental Research Letters.

The study relies on advanced modeling methods to provide the first truly comprehensive estimate of the global extent to which farmers use urban wastewater on irrigated cropland. Researchers analyzed data with geographic information systems (GIS) rather than depending on case study results, as in previous studies.

The researchers also assessed for the first time 'indirect reuse', which occurs when wastewater gets diluted but still remains a dominant component of surface water flows. Such situations account for the majority of agricultural water reuse worldwide, but have been difficult to quantify on a global level due to different views of what constitutes diluted wastewater versus polluted water.

Considering consumer safety the foremost priority, study authors highlight the need to mitigate public health risks through measures taken along the entire food supply chain. This includes improved wastewater treatment, but also preventive steps on farms and in food handling, since capacity for water treatment is increasing only slowly in developing countries.

According to the study, farmers' use of wastewater is most prevalent in regions where there is significant wastewater generation and water pollution. In these circumstances, and where safer water is in short supply, wastewater offers a consistent and reliable means of irrigating fields, including high-value crops, such as vegetables, which often require more water than staple foods.

Where raw wastewater is available, farmers may tend to prefer it because of its high concentrations of nutrients, which can lessen the need to apply purchased fertilizers. In most cases, however, farmers' use of this water is motivated by basic needs; they simply do not have alternatives.

"The de facto reuse of urban wastewater is understandable, given the combination of increasing water pollution and declining freshwater availability, as seen in many developing countries," said Anne Thebo, a recent graduate at the University of California, Berkeley in the USA and lead author of the study.

"As long as investment in wastewater treatment lags far behind population growth, large numbers of consumers eating raw produce will face heightened threats to food safety."

Results show that 65 percent of all irrigated areas are within 40 km downstream of urban centers and are affected by wastewater flows to a large degree. Of the total area of 35.9 million hectares, 29.3 million hectares are in countries with very limited wastewater treatment, exposing 885 million urban consumers as well as farmers and food vendors to serious health risks.

Five countries - China, India, Pakistan, Mexico and Iran - account for most of this cropland. These new findings supersede a widely cited 2004 estimate, based on case studies in some 70 countries and expert opinion, which had put the cropland area irrigated with wastewater at a maximum of 20 million hectares.

"Gaining a better grasp of where, why and to what extent farmers use wastewater for irrigation is an important step toward addressing the problem," said second author Pay Drechsel of the International Water Management Institute (IWMI), who leads the CGIAR Research Program on Water, Land and Ecosystems.

"While actions aimed at protecting human health are the first priority, we can also limit the hazards through a variety of tested approaches aimed at safely recovering and reusing valuable resources from wastewater. These include the water itself but also energy, organic matter and nutrients, all of which agriculture needs. Through such approaches, we have been helping the World Health Organisation (WHO) respond to the wastewater challenge over the years."

"We hope this new study will focus the attention of policy makers and sanitation experts on the need to fulfill Sustainable Development Goal 6, particularly target 3, which calls for halving the proportion of untreated wastewater, and increasing recycling and safe water reuse," added Drechsel.

"One major challenges is to cultivate behavior change from farm to fork, especially where risk awareness is low. Another consists of larger scale efforts to put the recovery and reuse of resources from wastewater and other waste on a business footing to make its management more attractive for the public and private sectors. Safe resource recovery and reuse have significant potential to address the health and environmental risks, while at the same time making cities more resilient and agriculture more sustainable, contributing to more circular economies."

Research paper

FARM NEWS
Study offers new approach to evaluating agricultural development programs
Boston MA (SPX) Jul 07, 2017
As the old saying goes, teaching someone to fish is far more helpful than just giving them a fish. Now, research from WorldFish and MIT takes that adage a step further: Better yet, the study found, is working with the fishermen to help develop better fishing methods. Involving local people in figuring out how to improve their farming and fishing methods provides more lasting and widespread ... read more

Related Links
IOP Publishing
Farming Today - Suppliers and Technology

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

FARM NEWS
Computer vision techniques shed light on urban change

Extreme low-oxygen eddies in the Atlantic produce greenhouse gases

Can satellites be used as an early warning system for landslides

Study finds Earth's magnetic field 'simpler than we thought'

FARM NEWS
India Plans to Roll Out National GPS Next Year

Orbital Alliance Techsystems receives contract for GPS artillery

Europe's Galileo satnav identifies problems behind failing clocks

New orbiters for Europe's Galileo satnav system

FARM NEWS
EU hauls Poland to top court over ancient forest logging

Ancient fungi could help Canada's future northern forests

UNESCO urges Poland to stop logging ancient forest

Green activists, rangers face off over Poland's ancient forest

FARM NEWS
Cutting the cost of ethanol, other biofuels and gasoline

Solving a sweet problem for renewable biofuels and chemicals

A whole-genome sequenced rice mutant resource for the study of biofuel feedstocks

New biofuel technology significantly cuts production time

FARM NEWS
There Will Always be Sun on this Horizon

SolarEdge Launching First PV Inverter-Integrated Electric Vehicle Charger

Investors Generate 174,000,000 kWh of Renewable Electricity

Solar cell design using diverse plant pigments

FARM NEWS
Algeria seen as African leader for renewable energy

Owls' wings could hold the key to beating wind turbine noise

Thrive Renewables delivers mezzanine funded wind farms in Scotland

It's a breeze: How to harness the power of the wind

FARM NEWS
China backs hundreds of global coal power projects

Rio prefers Yancoal to Glencore in Australia coal sale

Glencore makes new bid for Rio's Australia coal assets

Rio backs Yancoal over Glencore for Australia coal minesw

FARM NEWS
Anti-Beijing Hong Kong lawmakers disqualified from parliament

China hits back at criticism over Nobel laureate's death

China under pressure to free dissident's widow

China's ailing Nobel laureate in 'critical condition'




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement