From ashes to fly larvae, new ideas aim to revive farm soil

By RodNickel

WINNIPEG, Manitoba – As extreme weather conditions and human activity degrade the world’s farmland, scientists and developers are searching for new and largely untested methods to save land for agriculture.

One company is injecting liquid clay into the California desert to trap moisture and help fruit grow, while another in Malaysia is enriching the soil with fly larva droppings. In a greenhouse in Nova Scotia, Canadian scientist Vicky Levesque adds biochar — the burned residue of plants and wood waste — to the soil to help apples grow better.

Well-established techniques for soil conservation, e.g. Less tillage and off-season seeding cannot cope with more frequent droughts, floods and temperature extremes. Soil erosion depletes the soil’s ability to produce food and could result in a 10% loss in global crop production by 2050, according to the Food and Agriculture Organization of the United Nations.

New “soil conditioner” solutions that improve the physical properties of the soil can complement traditional methods – if they prove profitable and effective.

Biochar, liquid clay, and fly larva droppings are all in limited commercial production. The development of such solutions has accelerated in recent years as soil degradation worsened, said Ole Kristian Sivertsen, managing director of liquid clay company Desert Control, which made its first commercial sale in December.

Bayer AG, the world’s largest seed company, is among the companies looking at new ways to regenerate soil with Leaps by Bayer, its venture capital unit, said Matthias Berninger, Bayer’s head of sustainability.

Bayer and other companies are already working on non-chemical methods to add nutrients to plants, such as adding microbes to the soil, but products for regenerating farmland are taking it further. Some, like liquid clay and biochar, add nutrients while improving the soil’s ability to hold water and require fewer applications than fertilizer.

“We really started to focus on the ground in a way that we traditionally wouldn’t have done,” Berninger said in an interview.

Dark Earths

Biochar is an artificial means of creating a carbon-rich soil-strengthening product that is modeled after exceptionally fertile patches of the Amazon rainforest called “dark soils,” formed over time as a by-product of cooking, animal decomposition, and fertilizer are.

Biochar could be a “great opportunity” to capture plant-sustaining carbon in the soil, Levesque said, adding that biochar also acts like a water sponge.

Her research, which began in 2012, showed that clay soil treated with biochar emits dramatically less nitrous oxide, which benefits the atmosphere and traps more carbon in the soil, where it can boost plant growth.

Some types of biochar increased yields of greenhouse tomatoes and sweet peppers by 32% and 54%, respectively, while requiring less fertilizer because biochar boosts the proliferation of bacteria that promote plant growth.

But more research is needed before scientists know how effectively biochar could regenerate different types of soils around the world, she said.

Norway-based company Desert Control has invested 18 years and $25 million developing liquid clay to strengthen soil. Last year, it injected its product into a patch of US desert, where the clay combines with sand to better hold water and nutrients.

Preliminary data from a five-year trial showed that romaine lettuce hearts in clay-treated sand were, on average, 21-53% larger than romaine lettuce grown in the same conditions without clay, said Robert Masson, an official with the University of Arizona’s Yuma County Cooperative Extension that grew the plants.

In November, Desert Control signed a $182,000 contract with The Limoneira Company, which will initially apply liquid clay to 4,000 trees on two of its citrus orchards in the drought-stricken states of California and Arizona. Depending on the results, Limoneira intends to expand the application in the fourth quarter.

Each application lasts up to five years.

“Cover crops and no-till are good practices, but they’re far from enough,” said Sivertsen.

In Malaysia, Nutrition Technologies produces “soil conditioners” from frass – the waste and skin of black soldier fly larvae. Composted frass resulted in a 12% increase in plant-nourishing soil organic matter, something that otherwise declines over time, according to the company’s research.

Nutrition Technologies, which was founded in 2015, sells an average of 200 tons of Frass per month in Malaysia, mostly to growers who apply it to leafy greens, cucumbers and fruit, said Martin Zorrilla, the company’s chief technology officer.

The company raised $20 million in September, its latest funding round.

While most Malaysian fertilizer makers are now selling frass, volumes are still too small to attract the attention of global farming companies, Zorrilla said.

“Ultimately, soil is a living system, which is one of the reasons natural processes take so long to build soil and why it’s lost so easily,” he said.