Posts Tagged ‘drought’

Designing Drought-Resistant Crops

Wednesday, April 29th, 2009

Droughts are a farmer’s worst nightmare: Crops meant for the dinner table wither away in the dry heat leaving people hungry and farmers broke.

Not all plants are as sensitive to drought, though, and it is the genetic makeup of these more resilient plants that is of interest to scientists who feel the need to develop crops that can handle drastic shifts in their environments.

U.S and Finnish researchers recently discovered the specific gene responsible for controlling the amount of water released by the plant as it absorbs carbon dioxide-more specifically, the gene that controls the plant’s stomata.

The stomatic pore in a tomato leaf.
(Photo: Wikipedia)

All leaves are covered with stomata, which are tiny pores used to suck up carbon dioxide and to release water vapor back into the air.

Some of the ‘hardier’ plants close up their stomatal pores when ozone levels increase.

This reaction also reduces the amount of water lost during the harsher seasons. (It is interesting to note that plants suffer from excessive amounts of ozone rather than thriving in a CO2 rich environment when they use this specific gas for growth.)

The gene in question controls when the stomata are open or closed. Unfortunately, with their stomata closed, plants are unable to absorb the excessive amounts of CO2 in our atmosphere.

Up to 95% of water loss occurs through these pores while they are open, so manipulating the genetic makeup of plants to increase their sensitivity to droughts (forcing them to close their stomata) could have a positive effect on their survivability: A little water lasts much longer.

This may slow plant growth since CO2 is a necessary component for photosynthesis and plant development (with the stomatal pores closed, less CO2 makes it into the plants’ system), but a smaller plant is still better than a dead one.

Researchers claim that within the next few years plants could be genetically modified to hold on to the precious water that is so hard to come by during a drought, while still being able to absorb the CO2 they need for photosynthesis.  

This is a win-win situation: It will allow crops to survive in arid regions while also sequestering the atmosphere’s CO2.

via Science Daily

Turning Air into Water

Tuesday, December 2nd, 2008

40 percent of the world is dealing with a water shortage. This means that over 2 billion people have to survive in barren and often unsanitary conditions, while everything crumbles around them. Nothing can survive without water. Plants dry up, cattle starve to death, and people succumb to the ailments associated with drinking unsanitary water.

The irony is that water exists all around us. Water droplets shining on leaves in the morning seem to appear out of thin air. This is where companies like EWA Technologies and Air2Water will collect water.

EWA gives a rough estimate of how much water there actually is in our atmosphere: “Air humidity, an unlimited renewable natural resource, is available to all mankind, except in few extreme climatic regions where the temperature is bellow 4oC or extreme arid zone. One cubic kilometer of air contains 10 to 40 tones of life-giving water. Nature continually recharges the atmosphere with humidity by evaporation from the world’s oceans, seas and fresh water bodies.”

Both companies use similar technologies. Air is pulled into a machine where it is condensed into water after passing through a filtration system that removes airborne particles and bacteria. Air2Water also applies UV light to the collected water to ensure that consumers won’t sip up any bacteria or viruses as well.

More than one billion people currently
lack adequate or sufficient drinking water.
(Photo: EWA Technologies Group)

EWA prides itself on using as little energy as possible in the process. By using both residual water and solar heat to power their products, the price of producing water comes to about 5 US cents per cubic meter!

EWA is focused on providing the liquid to nations hit the hardest because of economic hardships and location; like rural villages nowhere near a river and without pipelines.

EWA uses a desiccant material to attract moisture. (Silica Gel and Rice (often found in salt shakers) are examples of desiccant materials that absorb moisture from the air.) The water is then collected through processes involving wind drying, heating and vacuum. EWA has a variety of models, all using the same technology, ranging from devices that produce a few liters to larger machines that pour out a whopping 1000 liters on a daily basis. Combining a few of the larger machines could fill up a swimming pool in no time!

Water has been a topic of debate for decades. WaterAsia is hosting their 9th international conference and exhibition this month, which focuses entirely on the water industry. Companies like EWA and Air2Water are sure to make an appearance alongside representatives of breweries, power stations, oil refineries, fiber plants and countless other companies that depend on water to function. It seems like everyone could benefit from a little more water at their disposal.