How to keep crops alive in a hotter, drier world

This content was published on February 16, 2022 – 11:00

(Bloomberg) – Each week, the University of Nebraska-Lincoln, the National Oceanic and Atmospheric Administration and the U.S. Department of Agriculture update America’s Drought Monitor, a map illustrating areas of the country currently experiencing a shortage of water, and to what extent .

In the West and the High Plains, which comprise 15 states with some of the most productive land in the country, the news for the past 20 years has not been good. Drought conditions have prevailed in more than 15% of the West for 1,138 of the past 1,144 weeks. California has spent eight of the last 10 years with more than half of its territory under pressure. As of February 8, 95% of the West was considered “abnormally dry.”

Farmers pay the price. In California, home to the country’s most profitable agricultural region, the San Joaquin Valley, warm-season temperatures have climbed 1.4ºC (2.5ºF) since the 1970s, and a projected increase of 2 additional ºC is planned for the middle of the century. For vegetation, an average difference of 1°C can be significant.

With global warming unlikely to slow anytime soon, California’s Fourth Climate Change Assessment (released in 2019) cited new technologies as both a means of mitigating and adapting crops to persistent water stress.

The opportunity was not lost for inventors or investors. Startups from Los Angeles to Switzerland have rolled out products. The value of deals in the agtech sector has grown every year for the past decade, nearly quadrupling since 2016. Last year, companies in the sector made investments of $7.8 billion.

But whether the new technology works as advertised, is affordable, and scalable enough remains an open question.

According to the United Nations, some 155 million people faced a food crisis in 2021, up from 135 million the previous year. This means (at the very least) that a household is severely malnourished or can only meet basic food needs by depleting essential assets. Among the main causes are climatic shocks, including extreme weather conditions triggered by accelerating warming, floods, droughts and subsequent population displacements.

Ariel Ortiz-Bobea is an Associate Professor and Research Fellow at Cornell University’s Atkinson Center for Sustainability. He said recent research by his team shows that “anthropogenic climate change has already slowed agricultural productivity growth globally”, losing the last 7 years of growth out of the last 60.

“Global agriculture, although more productive over time, is not becoming more resilient to high temperatures,” he said. “A sustainable future for agriculture in a world of rising global population and rising living standards requires that we improve productivity.” More land, labor and chemicals are not sustainable options, he said. So the answer is to invest in research and development.

Opti-Harvest, which markets itself as an “agricultural innovation company,” said it took this lesson to heart. Its products seek to compensate for the decrease in available water by accelerating plant growth. The Los Angeles startup produces specially colored polymer tubes, panels and cones that are placed on, above or around trees or other crops. The goal is to get more sun to the leaves that wouldn’t otherwise see it, at least not directly. Additionally, the mechanism also manipulates the spectrum toward more growth-oriented wavelengths, the company said.

Accelerated growth can mean crops need less water. “We basically irrigate with photons,” said Jonathan Destler, CEO of Opti-Harvest.

Opti-Harvest’s “canopy unit” looks like a huge mixing bowl sitting on top of a trash can. The device focuses light into a red tube, which has small holes to allow the reflected light to reach below the tree canopy, where it is normally shaded. Wavelengths in the red part of the light spectrum are conducive to growth, Destler explained. So Opti-Harvest said it worked with chemical giant BASF to find the right red pigment, adjusting the geometry to collect and scatter the light (too much, and the plant overheats).

Experts in plant physiology, horticulture and optical physics from Israel’s agriculture ministry and the Weizmann Institute of Science, an agri-tech hub outside Tel Aviv, were also involved in its development. , Destler said. According to Opti-Harvest, randomized trials at an experimental farm in California showed the mechanism caused more citrus fruit and increased nut yield by up to 24%.

John Bushoven is chair of the horticultural science department at Fresno State University. When he first heard what the company was doing, he said his first reaction was “it’s about time someone brought the greenhouse outside.”

Bushoven spoke of a pistachio orchard on the 36-acre Fresno State research farm, where he conducts root development research under contract with Opti-Harvest. His expertise consists of using ground-penetrating radar to measure root systems.

Pistachio and almond trees – high-value crops requiring years of investment and lots of land and water – are particularly vulnerable to temperature fluctuations and drought. Roots that penetrate deeper can access more water, requiring less irrigation, he said.

Although there is not enough water for everyone (especially for crops like almonds and pistachios), there is also far too much fertilizer used. Among other disadvantages, ammonium nitrate, a commonly used synthetic fertilizer, has negative effects on greenhouse gases. Although there are already devices being used to read nutrient levels in the soil to better target fertilizer use, Swiss company Vivent says it can do better.

The company’s product, PhytlSigns, consists of electrodes that penetrate a plant and measure electrical signals. Sensors and machine learning determine how a plant reacts to agricultural inputs — fertilizers, nutrients, water, pesticides — or even if it is attacked by pests, according to Vivent.

“We are guilty,” Vivent sustainability manager Marina Martin Curran said, “of torturing many tomato plants.”

Algorithms can tell users what kind of stress the plant is experiencing and what to do about it: add or reduce fertilizer input, apply more water or pesticides. The lack of nitrate produces a different type of signal than the lack of water, for example. “These signals vary depending on the health status of the plant,” Curran said. Whatever the stressor, “you’ll see useful data long before the leaves start to sag.”

The company said it focused on high-value crops such as tomatoes and cannabis due to the high cost of developing the technology. But Curran added “we are very keen to support grassroots crops.”

Vivent said it tested PhytlSigns on corn in the lab, and on soybeans and potatoes in the field. Outdoors, however, the signals are more difficult to read, creating a barrier to scalability. Maize “is more subject to wind and other physical stimuli, which can affect the signal,” said Daniel Tran, a researcher at Agroscope, a branch of the Federal Office for Agriculture that conducts research and development for the food industry.

And the larger the field or farm, the more difficult the topography makes it to choose a plant to “read” that represents the whole area. Nonetheless, Tran said his research shows that PhytlSigns has the potential to work across cultures, regardless of scale. , and impact investor Astanor Ventures. Vivent said much of the money will go towards developing a wireless system to deploy its technology, which the company hopes will make it cost-effective and scalable. “We hope to be able to provide farmers with the ability to significantly reduce their fertilizer inputs or give them more information about the specific nutrients a plant needs,” Curran said.

As growers need to become more resilient to global warming, a growing segment of the industry is focusing on reducing greenhouse gas emissions by employing microbes to do the work of fertilizers. This is called nitrogen fixation.

Certain microbes that live in the soil can produce nitrogen, reducing the need for added fertilizer. But if the microbes detect nitrogen in their environment, they stop making it. Legumes have developed what is essentially a safe house for microbes, where they live sheltered from the surrounding environment and thus continue to manufacture it. (That’s one of the reasons soybeans are a popular cover crop—needing no fertilizer, they’re cheap to grow.)

Pivot Bio, based in Berkeley, Calif., said it has developed a way to reprogram microbes to produce nitrogen, regardless of what’s going on around them. The company topped the agri-tech industry investment rankings last year with $430 million, according to PitchBook.

As synthetic fertilizer prices rose in 2021 to more than double their five-year average, Pivot said its products have become more attractive (although it declined to disclose their cost). Other companies in the field of microbial agriculture include New Leaf Symbiotics of St. Louis and Joyn Bio, a Boston-based joint venture between Gingko Bioworks and Bayer AG.

“Nitrogen fixation is the holy grail for cereals,” said Karsten Temme, managing director of Pivot.

Cornell’s Ortiz-Bobea said technologies such as those offered by Opti-Harvest, Vivent and Pivot Bio, while efficient and scalable, are not a panacea. These are just new tools among many, all of which must be used if the effect of the climate crisis on global food production is to be mitigated.

“What is most important is that investors have an incentive to invest,” he said. “Governments and international organizations have a role to play in promoting a framework to catalyze this.”

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