fertilizer

Making Use Of Invasive Seaweed | Earth Wise

June 26, 2020 By EarthWise Leave a Comment

In recent years, millions of tons of brown Sargassum seaweed have formed gigantic blooms stretching all the way across the Atlantic Ocean from West Africa to the Gulf of Mexico. The seaweed has become a problem for shorelines in the Caribbean, the Gulf of Mexico, and the east coast of Florida. The massive increase in seaweed populations is related to changes in ocean chemistry resulting from nutrients from fertilizer use entering the water as well as from changes to the climate affecting ocean currents and temperatures. The seaweed is harming the tourism industry as well as fisheries and ocean ecosystems.

Cleaning up the seaweed that washes ashore is labor-intensive and therefore expensive. A research team led by two British universities has developed a cheap and simple way to pre-process seaweed to facilitate making it into bulk chemicals and biofuels. With the new process, cleaning up the seaweed can be both economically and environmentally viable.

Previous techniques for processing seaweed generally required removing it from the saltwater, washing it in fresh water, and drying it – all of which add significant costs. The new technique makes use of catalysts to release sugars from untreated seaweed that feed a yeast to produce a palm oil substitute. At the same time, the process creates heat and pressure, turning the residual materials into a bio-oil that can be processed further into fuels, and a high-quality, low-cost fertilizer.

Apart from getting economic value out of the seaweed that is collected, any plastic collected alongside the seaweed can be converted to useful materials as well.

It appears that the seaweed scourge is here to stay, so finding an economically viable way to deal with it is a welcome development.

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Solve invasive seaweed problem by turning it into biofuels and fertilisers

Photo, posted August 10, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mexico’s Wonder Plant

September 13, 2019 By EarthWise Leave a Comment

In 1979, an American naturalist named Thomas Hallberg visiting a small town in Oaxaca, Mexico was amazed to find a type of local maize – or corn – that grew nearly 20 feet high in poor-quality soil even though the local farmers did not use any fertilizer.

The unique corn plant had aerial roots that grew a mucous-like gel just before harvest season. It seemed totally implausible, but the plant seemed to be fixing its own nitrogen: extracting it from the air and somehow making it useful to the plant.

In 1992, Hallberg returned with a group of Mexican scientists and collected samples to study in his lab. His research showed that the maize indeed received nitrogen from the air through its aerial roots. It took over 20 years to figure out what was going on in the plants. It turns out that bacteria that thrive in the low-oxygen environment of the maize’s mucus pulls nitrogen from the air and feeds it to the plant.

Scientists will probably spend years figuring out if a commercial application of this indigenous maize is viable. It isn’t guaranteed that the self-fertilizing trait of the plant can be bred into a commercial crop. But if it can, the payoff would be huge. Farmers spend more than $3 billion a year on corn fertilizer in the US alone.

A vexing problem is who should reap the financial benefits of the maize. The isolated village where the plant is grown has already signed an agreement to share in any such benefits. But there are other Oaxacan villages that also grow the plant.

Mexico’s wonder plant is likely to be caught up in the growing issue of biopiracy, which is the exploitation of indigenous knowledge and biological resources without permission.

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Indigenous Maize: Who Owns the Rights to Mexico’s ‘Wonder’ Plant?

Photo credit: ALLEN VAN DEYNZE/UC DAVIS

Earth Wise is a production of WAMC Northeast Public Radio.

Powering Cars With Cactus Juice

June 24, 2019 By EarthWise Leave a Comment

Back in 2016, a company called Nopalimex, located in Micoacan, central Mexico, built the world’s first cactus-powered energy plant. The facility utilizes a biodigester to make biogas from nopal, also known as prickly pear cactus. The nopal plant has been called the ‘Green Gold of Mexico’ and is a staple in Mexican diets, medicine and cosmetics.

Nopalimex is now using the cactus to make biofuel for vehicles.

The fruit of the cactus is pureed, mixed with manure, and then left to decompose, producing methane. The methane produced – about eight tons a day – fuels the biodigester which powers the company’s corn chip and cactus chip production and is being tested in a fleet of government vehicles.

The biogas will cost just 65 cents per liter, which is about a third cheaper than the cost of regular gasoline. Using prickly pear as a feedstock for biofuel is attractive because it can be grown in places where traditional energy crops cannot. One can imagine vast fields of cacti in remote, arid areas of the country where normal crops cannot grow. It would not suck up the resources or space needed to feed people, which is an ongoing criticism of current bioenergy crops.

As long as the nopals are regularly replanted, the process is almost entirely sustainable, producing only water and nopal waste, which can be used to fertilize other crops.

Finding sustainable ways to produce fuel while doing minimal damage to the environment is an important challenge for countries around the world. In Mexico, harnessing the power of the prickly pear cactus is a unique and clever solution.

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Mexico’s ‘green gold’: The company powering cars with cactus juice

Photo, posted July 8, 2006, courtesy of Christian Frausto Bernal via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Microplastics In Soil

May 4, 2018 By EarthWise Leave a Comment

Many of us are well aware of the environmental challenge faced because of the proliferation of plastics. Since plastic does not decompose naturally, most of it remains in our environment. Only 12% has been incinerated and only 9% has been recycled. A great deal of plastic ends up in the ocean and other bodies of water. Much of it breaks down into small particles – microplastics – which are now ubiquitous in the oceans. There are also microplastics that started out that way in the form of little beads used in the cosmetics industry. Studies have found microplastics in the bodies of 73% of fish from the North Atlantic.

Tree-Planting Drones

March 16, 2018 By EarthWise Leave a Comment

One of the major causes of the increasing carbon dioxide levels in the atmosphere is deforestation. We chop down about 15 billion trees each year. Over time, our activities have reduced the number of trees on earth by about 50%. We do plant trees – these days, about 9 billion a year. It is a substantial number, but still leaves a net loss of 6 billion trees annually.

[Read more…] about Tree-Planting Drones

Small Grains In Corn Country

January 31, 2018 By EarthWise Leave a Comment

Large portions of the Midwest are called the Corn Belt and for good reason. Overall, about 90 million acres or 140,000 square miles of the United States are planted with corn and about half of that is in Iowa, Illinois, Nebraska and Minnesota. In most of the Corn Belt, the corn is planted in rotation with soybeans. Both are warm weather crops and the soil is left barren for nearly half of the year when the two crops are out of season.

Raw Wastewater On Farms

August 21, 2017 By EarthWise

Clean water supplies are dwindling around the world. As a result, the use of untreated wastewater on farms for crop irrigation is on the rise.

Solar Power From An Old Mine

May 8, 2017 By EarthWise

For more than a century, a wide stretch of land north of Kimberley, British Columbia, was used for intensive industrial hard-rock mining. The site of Teck’s Sullivan Mine hosted a steel mill, a fertilizer plant and tailings ponds and was rendered treeless.

Lake Baikal

January 4, 2017 By EarthWise

Lake Baikal is an ancient and massive body of freshwater found in the mountainous Russian region of Siberia. Deep and voluminous, Lake Baikal holds 20% of the planet’s unfrozen freshwater. And it’s often been described as the world’s cleanest and most pristine lake.

[Read more…] about Lake Baikal

Restorative Ocean Farming

November 16, 2016 By WAMC WEB

The conventional aquaculture industry has often been associated with many of the same problems that beset land-based agriculture: creating sterile monocultures, fouling the environment with pesticides, antibiotics and organic pollutants, and spreading diseases.