‘Bubble-Greenhouses’ turn salt water into fresh water

Photo credit: SciDevNet

Copyright: Carolyn Drake/Panos

Bubble desalination latest effort to boost crop growth

 

“We believe that the concept is applicable to arid regions worldwide.” Mario Schmack, Murdoch University

by Ian Randall

Speed read

  • Low-tech ‘Bubble-Greenhouses’ turn salt water into fresh water
  • They also create cool, humid conditions for better growth
  • Researchers are seeking partners to make prototype

Researchers in Australia are seeking to build a prototype ‘Bubble-Greenhouse’ that could provide remote, arid places with a low-tech, low-maintenance way to turn salt water into fresh water to grow food.

The engineers from Murdoch University, who published their study last month in the journal Desalination, estimate that a 150 square metre Bubble-Greenhouse could produce around eight cubic metres of fresh water and up to 30 kilograms of crops each day. The sealed structure would protect crops from insects and disease, while the technology should be relatively simple to implement and use in isolated areas, they say.
The Bubble-Greenhouse idea develops an existing seawater greenhouse concept, which uses the evaporation and condensation of salt water to produce fresh water for irrigation and to create a cool, humid environment inside a greenhouse, meaning crops need less water to grow.

The new approach moves the evaporation and condensation processes outside the greenhouse. Inside two water-filled ‘bubble columns’, streams of thousands of tiny bubbles create a large surface for water to evaporate or condense. A unique property of seawater prevents the small bubbles joining to form big bubbles, thus maintaining a large surface area.

Read the full article: SciDevNet

If the last good time to plant a tree was 20 years ago, the next is now!

Photo credit: Dawn

Watering the maritime desert

by ZAHRA ALI HUSAIN

With its extreme heat and drought-like conditions, Karachi has begun to raise an alarm: this is what global warming looks like and it now knocks on our doorstep.

“Karachi has been recognised as a maritime desert,” explains Rafiul Haq, an ecologist by profession and founder member of Coastal Restoration Alliance for Biodiversity (CARB). “It is located in a subtropical arid zone with an average rainfall of less than 220 mm/year. Such fragile climatic conditions are sensitive to any change.”

Extreme weather conditions are linked to global climate change, which is a result of unnecessarily exhausting natural resources. In a city of about 20 million, the endless use of air conditioners, excessive travelling and even eating meat more than we need, is all adding up to a bigger carbon footprint.

“The settled residential areas are now surrounded by high-rise buildings, which contribute to municipal, social and ethical issues. Recent unplanned and uncontrolled development has greatly ignored the fragile nature of the city’s climate,” argues Haq.

Is there a way to reverse the process?

The consensus among environmentalists is to plant more trees, and then some more. It seems like an obvious and sensible thing to do, but not many heed the lesson.

“Trees play a vital role in moderating the micro climate,” explains Haq. “Besides being good absorbents of radiant energy, producing oxygen and maintaining temperature through perspiration, they definitely contribute in increasing the chances of rain.”

Read the full article: DAWN

Gaz et désertification / Gas and desertification (French text)

Français/ French

Photo credit: Le Monde

Niger : le gaz pour enrayer la désertification

Le Monde.fr avec AFP

EXTRAIT

L’objectif ? Promouvoir le gaz plutôt que le charbon de bois

Car « plus de 90 % » des ménages n’utilisent que le charbon de bois (fabriqué à partir de bois, alors même que le sous-sol contient du charbon fossile) pour se chauffer durant le court hiver nigérien, s’éclairer et cuisiner à longueur d’année, selon les services nigériens de l’environnement. Quelque 200 000 tonnes de bois sont ainsi consommées tous les ans, soit« l’équivalent de 100 000 hectares de forêt détruits », s’alarme Ibro Adamou, un agent des eaux et forêts.

L’impact est intenable pour l’aride Niger, dont le nord est recouvert par le Sahara. « Nous sommes aux portes du désert et nous continuons à détruire le peu de bois qui nous reste », peste Moustapha Kadi, dirigeant de l’ONG Coddae, qui promeut l’accès à l’énergie.

Depuis 1990, les zones forestières du sud ont perdu « un tiers » de leur surface, pour ne plus représenter que « 1 % du pays », d’après le Programme des Nations unies pour l’environnement (PNUE).

Lire aussi : L’Afrique n’est pas victime de ses frontières !

« Avant on coupait du bois à cinq kilomètres de Niamey. Aujourd’hui, il faut aller à 200 kilomètres, à l’intérieur du Burkina Faso voisin », explique Hama Maïgari, un vendeur de bois.
Faute d’arbres, le désert s’étend inéluctablement et « engloutit doucement les terres fertiles », au moment où « la population de plus en plus nombreuse en a besoin pour l’agriculture », déplore l’expert onusien.

Etat le plus fécond au monde, avec 7,6 enfants par femme, le Niger devrait voir sa population tripler d’ici 2050, pour passer de 17 à 56 millions d’habitants.

Les surfaces arables sont en ce sens autant de trésors pour un pays abonné aux crises alimentaires, notamment dues à la sécheresse et aux changements climatiques, où 80 % de la population vit d’une agriculture de subsistance.

Lire le texte en entier/ Read the full text: Le Monde

MY WEBSITES AND FACEBOOK PAGES (Willem Van Cotthem)

For those who missed them

MY WEBSITES AND FACEBOOK PAGES (Willem Van Cotthem)

CONTAINER GARDENING ALLIANCE: https://www.facebook.com/willemvancotthem
DESERTIFICATION FIELD PRACTICES: https://www.facebook.com/groups/273559399327792/
CONTAINER GARDENING AND VERTICAL GARDENING: https://www.facebook.com/groups/221343224576801/

Toprağa Giriş – Earth Log in

 

Video on soils

https://youtu.be/RhxRm9_eivc?list=PLzp5NgJ2-dK7iaOH5OKUYYRVOROUMEztd

 

If we protect our soils and manage them sustainably we can combat climate change.

 

A look at how our Soils help to combat climate change in their role of sequestering CO2, and how our collective habits can damage this benefit with potentially devastating consequences.

S.O.S. – saving the vital resource soils

Photo credit: Food Tank

Food Tank discusses what each of us can do to protect soil health with Michaël Wilde from the Save Our Soils campaign.
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Save Our Soils

The U.N. Food and Agriculture Organization (FAO) has named 2015 theInternational Year of Soils. Soil is one of the earth’s most valuable natural resources, and Food Tank recently discussed the importance of saving this vital resource with Michaël Wilde from the Save Our Soils campaign.

Food Tank (FT): What is the importance of the International Year of Soils?

Michaël Wilde (MW): The International Year of Soils, initiated by the FAO, is extremely important because it gives us a stage to inform the media and the public about how important soil is for our planet. The European Union refers to Soil as one of the earth’s most important yet most neglected resources, so we really need to grab this opportunity to let everyone know about the soil crisis and also about the Soilutions!

FT: How much soil is being lost?

MW: Every minute we lose the equivalent of thirty soccer fields of soil. As a result, we are losing 10 million hectares of farmland every year. Furthermore, it is estimated that one-quarter of the earth’s soils are highly degraded.

FT: What is causing soil degradation?

MW: Erosion is the most common form of soil degradation. When soil is left exposed to wind and rain, erosion occurs. Soils with low organic matter content will erode more easily. These soils are less able to retain water and can, therefore, be easily washed or blown away by the wind. Agriculture is responsible for three-quarters of the erosion worldwide. The erosion takes place due to poor treatment of the soil and frequent removal of the vegetation. Because of these practices, erosion on farmland is estimated to be 75 times bigger than natural erosion in forest areas. Deforestation and urbanization are also responsible for the current soil loss and degradation.

FT: What impact can soil degradation have on food security, climate, and public health?

 

Read the full article: Food Tank

Educational materials on the critical role of healthy soils

Photo credit: FAO

The series “Dig It: The Secrets of Soils” is available in multiple languages.

New initiative looks to bring soils into classrooms around the globe

A new series of educational materials is teaching children the importance of healthy soils for our food, environment, livelihoods and well-being.

Developed by FAO and the Washington D.C.-based National Association of Conservation Districts (NACD) as part of the 2015International Year of Soils (IYS2015), the materials target children aged 5 to 14, using word games, puzzles, drawing activities and other interactive elements.

The four educational booklets are separately designed for beginner, intermediate, advanced and young adult students, with an accompanying educator’s guide for teachers.

Originally produced in English to complement the exhibit on soils at the Smithsonian National Museum of Natural History, the materials have been translated into French, Spanish, Italian, Chinese, Arabic and Russian, and the content has been slightly adapted to suit the needs of different FAO member countries. All of the booklets are available for download on the FAO International Year of Soils website.

FAO is now collaborating with governments who wish to translate the materials into additional languages to be used in primary and secondary school curricula. Once finalized, all of the materials will be available online for free use by member countries, teachers and students, just in time for the beginning of the new school year in the Northern Hemisphere.

Read the full article: FAO