DARFUR] Hawa Osman is a farmer in Darfur, Sudan. She grows tomatoes, okra, carrots, and rocket lettuce, and also has small orchard of guava trees.

In the hot weather of Darfur, Hawa used to lose half of the crops she hoped to sell each day in the market of Al Fashir, the capital city of North Darfur, because of inadequate storage facilities — and no electricity or refrigerator — in her small canteen, the shed made out of wood and palm leaves in which she displays her products to clients.

But these days she is selling fresher produce and making bigger profit. This is because of an ingenious device — the zeer pot — that was invented by a Nigerian teacher, Mohammed Bah Abba and introduced to Darfur last year.

The zeer is a large pot inside which fits another smaller pot with a clay lid. The space between the two pots is filled with sand, creating an insulating layer around the inner pot. The sand is then kept damp by adding water at regular intervals — generally twice a day — reducing the temperature within the inner post decrease.

Each zeer can contain 12 kg of vegetables, and costs less than US$2 to produce.

Experiments assessing its ability to extend shelf life show that tomatoes and guavas can be kept for 20 days, compared to just two without. Even rocket, which usually lasts only a day before wilting, can be kept for five days.

Amina Abas, who sells zeers in the Al Fashir marketplace, says that she has found a high demand for the pot, as almost every family accommodates a family of refugees from the fighting in the region.

"As a result, there is a need for zeer for keeping water and vegetables and preserving fruit to meet the needs not only of the host family, but also of the refugee family," she says. "It is really great."

Hawa was the first person to use the zeer technology in her canteen. An information sheet attached to the pot tells her how long different produce can be kept.

Before getting her zeer Hawa used to have to carry any unsold crops home each day. During the six-hour walk the vegetables would end up rotten because of the heat.

Preservation is a key issue for food security. A good harvest is a rarity in the harsh climate of North Darfur; but even when farmers and small-scale producers produce a strong crop, they still face the problem of preserving the fruit and vegetables they've grown.

Dry heat and dust reduce the 'shelf-life' of foods such as tomatoes, okra and carrots to as little as two or three days, making it essential to get good quality produce quickly into the marketplace. And the fact that food must be consumed quickly means that wastage is high.

Since its introduction in November 2002, 110 families in Darfur have adopted the zeer. On average, two zeers are used in homes, while women on the market will have three to four.

"It is simple and appropriate technology to me, as a farmer always works to keep her produce fresh and in top condition," says Hawa. "I was able to understand and use it within a week, and the technology rapidly became my bread and butter."

She points out that she has to look after both herself and three children. "This technology has helped me gain a suitable income to meet my family's daily needs. I see it as the most positive turning point in my life, in that it has allowed me to become self-sufficient."

Furthermore, both producer and consumer benefit. For the farmer, the zeer increases sales opportunities and for the consumer the result is an increased supply of vegetables and fruits in marketplace.

The zeer is the brainchild of teacher Mohammed Bah Abba. Bah Abba passed his idea to the Intermediate Technology Development Group (ITDG), which, with the assistance of researchers at the University of Al Fashir, carried out experiments to measure its value in maintaining nutrient content and extending the shelf life of vegetables.

As a result, the Women's Association for Earthenware Manufacturing in Darfur, with the support of ITDG, is now producing and selling zeers for food preservation in the Al Fashir area.

Iman Mohamed Ibrahim of ITDG says women using the zeer to preserve their vegetables on the market can make an additional 25 to 30 per cent profit on their income.

He points out, however, that it can have many other uses. "It can be used for storing sorghum and millets for a long time, as it protects from humidity when it is dry, preventing fungi from developing."

The zeer can also keep water at a temperature of about 15 degree Celsius. "In the camp, it is used as a water pot, to store relief items, and even as a clothes cupboard," he says.

There is also a health benefit. Mahmoud Ali, hygiene officer for the Al Fasir Municipality, says the zeer helps maintain the vitamin and nutrient content of the vegetables, and prevent disease by keeping flies off the food.

"Before the technology came along, vegetables on the display shelves attracted flies, resulting in stomach disease such as dysentery, " he says. "Now that vegetables can be kept fresh for longer and away from flies, there is a remarkable decrease in such sorts of cases."

Musa Elkheir is Knowledge and Information Officer at the IntermediateSo what’s modern+green about a couple of terracotta pots? Nothing and everything. The oldest known African earthenware has been found in Nigeria, so that ain’t exactly new. What does brings it up-to-date is the incredibly simple application of two pots, one inside another. Fill the space between the two with moist sand, and you have a most ingenious fridge. (That’s very modern if you live in one of the 90% of villages that don’t have electricity.) The water in the sand naturally migrates towards the outer pot, where it evaporates causing a temperature drop around the inner pot.* The principle is not new - we’ve mentioned the coolgardie safe <http://www.treehugger.com/files/2005/08/coolcool_-_cele.php> before, as just one such rendering on the concept. No, what is remarkable here is that Nigerian teacher, Mohammed Bah Abba, did not merely reinvent the idea, he made it a reality for tens of thousands of impoverished Nigerian women and farmers. By setting up the local production facilities to provide the pot-in-pot for $2 (since lowered to just 40c), he allowed perishable food to extend their spoilage rate. "Eggplants, for example, stayed fresh for 27 days instead of three, and tomatoes and peppers lasted for three weeks or more. African spinach, which usually spoils after a day, remained edible after 12 days in the pot-in-pot."

Being able to store crops, and family food, without need of electricity increased incomes and reduced levels of disease. In recognition for his part in bringing this amazing technology to people in need, Mohammed was awarded a $75,000 Rolex Award <http://www.rolexawards.com/special-feature/inventions/abba.html>. Having funded the first 7,000 pots from his own purse, he now used the award funds to distribute a total of 91,795 pot-in-pots by 2005.

It was a simple idea, but one with massive repercussions. For example, young women who had to hawk food before it perished, now have the opportunity to attend school and gain an education. The downstream results of which are simply immeasurable. Mohammed has also been asked to consider "adapting his cooling device in Eritrea, where it could preserve insulin vials for diabetic patients in remote rural areas, India, Haiti and Honduras." And he has been requested to facilitate workshops in Brazil. Already the pots performance has seen the Darfur’s Women’s Association for Earthenware Manufacturing produce their own version, known as a zeer pot <http://www.itdg.org/?id=annual_review_2003>, with resulting incomes for women increasing by 50%. So well worthy of being listed a Time magazine Invention of the Year <http://www.time.com/time/2001/inventions/basics/inpot.html> (2001). Oh, and The Shell Award for Sustainable Development <http://www.worldaware.org.uk/awards/awards2001/mobah.html> too.

As we keep saying around here, never believe that myth that one person cannot make a difference. We all affect the whole around us, Mohammed is but one example of how positive that change can be.

::Rolex Awards <http://www.rolexawards.com/laureates/laureate-6-bah_abba.html>.

* Garrett Rueda, a student in California scientifically tested <http://www.usc.edu/CSSF/History/2003/Projects/J0226.pdf> (PDF) the system, and found that the average temperature difference between the pots was a very significant 14°C (23.5°F) !