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WSU’s Green Times – April 2015

Posted by | April 29, 2015

Study puts a price on help nature provides agriculture

Farmers use cover crops like hairy vetch mixed with triticale or rye grass to supply organic matter to soil and make nitrogen available to plants. (Photos by Sylvia Kantor, WSU)
Farmers use cover crops like hairy vetch mixed with triticale or rye grass to supply organic matter to soil and make nitrogen available to plants. (Photos by Sylvia Kantor, WSU)

Scientists from Australia, Denmark, New Zealand, the United Kingdom and the United States describe the research they conducted on organic and conventional farms to arrive at dollar values for natural processes that aid farming and that can substitute for costly fossil fuel-based inputs. The study appears in the journal PeerJ.

“By accounting for ecosystem services in agricultural systems and getting people to support the products from these systems around the world, we move stewardship of lands in a more sustainable direction, protecting future generations,” said Washington State University soil scientist John Reganold, one of the study’s authors.

Tests in organic and conventional fields

Earthworms turning the soil, bees pollinating crops, plants pulling nitrogen out of the air into the soil and insects preying on pests like aphids – these are a few of nature’s services that benefit people but aren’t often factored in to the price we pay at the grocery store.

The value of ecosystem service benefits provided to people by nature is rarely quantified experimentally in agricultural studies and is generally not taken into account in the real world of economic markets.

The research team led by Harpinder Sandhu at Flinders University in Adelaide, South Australia quantified the economic value of two ecosystem services – biological control of pests and the release of nitrogen from soil organic matter into plant-accessible forms – in 10 organic and 10 conventional fields on New Zealand grain farms.

Values greater for organic systems

Root nodules on hairy vetch store nitrogen captured from the air with help from Rhizobium bacteria. The stored nitrogen is released into the soil when the plant dies and decomposes in place.
Root nodules on hairy vetch store nitrogen captured from the air with help from Rhizobium bacteria. The stored nitrogen is released into the soil when the plant dies and decomposes in place.

The values of the two ecosystem services were greater for the organic systems, averaging $146 per acre each year compared to $64 per acre each year in their conventional counterparts.

The combined economic value, including the market value of the crops and the non-market value of the two ecosystem services, was also higher in the organic systems, averaging $1,165 per acre each year compared with $826 per acre each year in conventional fields.

The study showed that the value of the two ecosystem services on the organic farms exceeded the combined cost of traditional pesticide and fertilizer inputs on the conventional farms. The scientists calculated that the potential value of these two services could exceed the global costs of pesticides and fertilizers for growing similar crops, even if the two services were used in just 10 percent of the world’s cropland.

Economic incentives necessary

The study indicates that widespread conversion to organic agriculture is not required to reap the benefits of nature. The value of ecosystem services can be realized by conventional and other farming systems by adopting farming practices like diverse crop rotations and cover crops.

Farmers rely on pollination services provided by bees for many crops including apples.
Farmers rely on pollination services provided by bees for many crops including apples.

Reganold said that government payments or market rewards for ecosystem services are likely required to ensure the widespread utilization of ecosystem strategies to enhance agricultural sustainability.

“Many people think it’s the responsibility of farmers to enhance the benefits that nature provides,” Reganold said. “But it’s not always economically feasible because the current market system doesn’t recognize the value of these services.”

The study was funded by the New Zealand Foundation for Research, Science and Technology.

The paper is Sandhu et al. (2015), Significance and value of non-traded ecosystem services on farmland. PeerJ 3:e762; DOI 10.7717/peerj.762.

Study points the way toward producing rubber from lettuce

Prickly lettuce, a common weed that has long vexed farmers, has potential as a new cash crop providing raw material for rubber production, according to Washington State University scientists.

Prickly lettuce, the wild relative of cultivated lettuce, is a potential source for the production of natural rubber. (Photo by Flickr user Jim Kennedy)

Prickly lettuce, the wild relative of cultivated lettuce, is a potential source for the production of natural rubber. (Photo by Flickr user Jim Kennedy)

Writing in the Journal of Agricultural and Food Chemistry, they describe regions in the plant’s genetic code linked to rubber production. The findings open the way for breeding for desired traits and developing a new crop source for rubber in the Pacific Northwest.

“I think there’s interest in developing a temperate-climate source of natural rubber,” said Ian Burke, a weed scientist at WSU and a study author. “It would be really great if prickly lettuce could become one of those crops.”

Potential for sustainable source

When the lettuce we eat and grow in our gardens bolts, a milky white sap bleeds from the stem. In prickly lettuce, the wild relative and ancestor of cultivated lettuce, this same substance could prove to be an economically viable source of natural rubber and help alleviate a worldwide threat to rubber production.

Natural rubber is the main ingredient for many everyday products, from boots to condoms to surgical gloves. Roughly 70 percent of the global supply of rubber is used in tires.

But more than half of rubber products are made from synthetic rubber derived from petrochemical sources. And the largest source of natural rubber, the Brazilian rubber tree, is threatened by disease.

Burke has reviewed many studies of prickly lettuce and its cultivated cousins, but one in particular gave him an idea. A study published in 2006 found that the latex in prickly lettuce was very similar to the polymers found in natural rubber.

“It occurred to me that we could grow the heck out of prickly lettuce in eastern Washington,” he said.

The milky sap, or latex, of the plant could be used to produce rubber. (Photo by Jared Bell, WSU)
The milky sap, or latex, of the plant could be used to produce rubber. (Photo by Jared Bell, WSU)

Genetic markers for desired traits

He knew that to develop a viable new crop for rubber production, he had to start by understanding the genetics of rubber production in the plant.

Burke, doctoral student Jared Bell and molecular plant scientist Michael Neff began their studies with two distinct samples of prickly lettuce collected from eastern Washington. These differed in their rubber content, leaf shape and tendency to bolt. The scientists were able to identify genetic markers not only for rubber content but for the way the plants grow, including the number of stems produced and bolting.

Sought-after traits in cultivated lettuce – like abundant leaves, a single stem and delayed bolting – are the exact opposite of traits desired for rubber production. Early bolting plants with multiple stems would allow for multiple harvests over the season and potentially maximize rubber yields.

Burke said that selecting for other traits, like water use efficiency, could allow prickly lettuce to be grown with minimal rainfall, meaning it could be grown in rotation with other crops.

The study was funded in part by a special U.S. Department of Agriculture/NIFA grant – Biomass for Biofuels and Bioproducts from Weedy Plants.

See Bell et al. (2015). Genetic and biochemical evaluation of natural rubber from Eastern Washington prickly lettuce (Lactuca serriola L.), Journal of Agricultural and Food Chemistry 2015, 63, 593-602.

‘Few Know the Blood We Shed,’ Say Seattle’s Hmong Farmers

Cheu Chang, right, at the Indochinese Farm Project in Woodinville in the mid-80s. Photo by Sharon Coleman/WSU.
Cheu Chang, right, at the Indochinese Farm Project in Woodinville in the mid-80s. Photo by Sharon Coleman/WSU.

If you’ve bought one of those big flower bouquets at Seattle’s Pike Place Market, there’s a good chance a Hmong farmer sold it to you.

Bee Cha’s family has a flower stand at this bustling market. He points down the long row packed with tulips, dahlias and peonies.

“From here on, they’re all Hmong farmers,” he says. “Everybody knows everybody.”

Cha, 40, is a coordinator with Washington State University’s Small Farms program. He has worked with a lot of Hmong farmers on business and marketing skills.

Listen to or read this story published by KUOW.

WSU researchers, sleuth resurrect ‘lost’ apples of the Palouse

Researchers at Washington State University have teamed up with an amateur apple detective to bring fruit varieties thought extinct back to life.

Fruit trees have survived on the slopes of Steptoe Butte since they were planted from 1888 to 1894 by homesteader Robert E. Burns. Seth Truscott/CAHNRS photo
Fruit trees on the slopes of Steptoe Butte have survived since they were planted 1888 – 1894 by homesteader Robert E. Burns. Photo by Seth Truscott/WSU

A team with the Department of Horticulture joined apple sleuth David Benscoter to take cuttings at an abandoned orchard that has survived for 125 years on the slopes of Steptoe Butte, a 3,600-foot mountain on the Palouse.

Now, they’re grafting and growing those cuttings, preserving valuable traits so that some day consumers will bite into long-lost varieties once again.

Steptoe’s lost orchard

“The Palouse used to be the cradle for orchards,” said Amit Dhingra, an associate professor of horticulture.  When irrigation arrived in the Columbia basin, the Palouse industry was decimated, but the trees survived.

A century later, people are exploring abandoned orchards and reviving lost apple types nationwide.

“Our food habits are changing,” said Dhingra. “Consumers are demanding more variety. These apples are a way to get variety and reclaim our heritage.”

Last autumn, Benscoter, a WSU alumnus and retired law enforcement officer, sampled an apple from a tree at Steptoe Butte. Based on the taste, color, shape and core appearance, experts said the apple was the Nero, a variety grown across the United States a century ago but believed to be extinct at the time.

Robert Edward Burns, who homesteaded on the northeastshoulder of Steptoe in 1888, planted this Nero. He planted fruit trees where he couldn’t grow wheat.

Burns’ orchards stretch along ravines and slopes to catch any water that flows down the mountain. Their roots are shaded from the sun in Steptoe’s deep soil. While some of Burns’ trees are dead after more than a century, others are overgrown and scraggly but very much alive.

“The trees are still producing!” said Nathan Tarlyn, a research assistant in Dhingra’s laboratory who cut scions with Benscoter at Steptoe. “One hundred and twenty-five years, and they’re in good shape.”

Burns’ orchard days didn’t last long. Benscoter believes he planted too many apple varieties, instead of concentrating on the six most popular apples in the east, where most apples were shipped. By 1899, Burns lost the farm and soon moved away from the Palouse. But his fruit trees still remain at Steptoe, a living gene bank that preserves variety for future breeders.

“I find it incredible that Burn’s failure as a farmer may lead to one of the biggest finds of named lost varieties in one location,” Benscoter said.

Apple detective

David Benscoter, an amateur apple detective, holds a pruned branch of a 125-year-old apple tree found at Steptoe Butte. Directly behind him is a tree believed to be a formerly-thought-extinct variety called Nero. Seth Truscott/CAHNRS photo
David Benscoter, an amateur apple detective, holds a pruned branch of a 125-year-old apple tree found at Steptoe Butte. Photo by Seth Truscott/WSU

Benscoter has a passion for tracking down apples. An amateur apple detective for the past seven years, he’s given talks across the state about varieties grown in Whitman County, 10 of which are still lost.

To find lost apples, Benscoter talks with Palouse residents and pores through old newspapers, plat maps, county fair records and family histories to learn what was planted, and who planted them. He compares that list with varieties thought to be lost or extinct. Then, it’s a matter of going to old orchards in the autumn and tasting the goods.

If he finds a lost-apple candidate, he sends it to identification experts based in Oregon. Using detailed descriptions written in the 19th and early 20th century, as well as old watercolor paintings, they check the flavor, shape and form of the apple, and inspect the structure of its core. If an apple fails in only one identification marker, it must be collected again the following year and sent to other experts across the United States.

Nathan Tarlyn, research assistant in Dhingra’s Genomics and Biotechnology laboratory, shows the ‘Nero’ tag on a grafted apple tree created with scions from century-old apples discovered on the Palouse. Seth Truscott/CAHNRS photo
Nathan Tarlyn, research assistant in Dhingra’s genomics and biotechnology laboratory, shows the ‘Nero’ tag on a tree grafted from century-old apples discovered on the Palouse. Photo by Seth Truscott/WSU

Scions and spitters

From cold storage at the WSU Vogel Plant Biosciences building, Tarlyn carried out a tiny apple tree with bandaged branches, each hung with a silver tag and a name: Nero, Arkansas Beauty, Scarlet Cranberry and Fall Jeneting.

“This is a bit of a Frankenstein,” said Tarlyn. “These are lost apple scions, grafted onto a host.”

On a base of standard rootstock, Tarlyn attached four heirloom varieties— three discovered on Steptoe, one, Fall Jeneting, found in nearby Colfax, Wash. Two of the apples, Fall Jeneting and Nero, have been confirmed as rediscoveries. Arkansas Beauty and Scarlet Cranberry are considered possible rediscoveries and must undergo further analysis.

Apple trees do not breed true. Apples can and do cross-pollinate, but out of hundreds of seedlings, only a handful will carry on desirable characteristics. Most feral seedlings are dubbed ‘spitter apples’ (“You take a bite, and spit ‘em out,” Tarlyn said.).

Breeders have long known that keeping desirable traits and making new apple varieties requires grafting.

“If a tree was any good, you gave it a name,” Tarlyn said. “If somebody liked that apple, you’d take cuttings, or scions, off it, and graft them onto other trees to get that apple back.”

Artist Charles Steadman painted this watercolor of a Nero apple, now in the USDA Pomological Watercolor Collection, in 1925. Nero was believed to be lost; WSU researchers are trying to bring it back using cuttings from a ‘lost’ Palouse orchard. Special Collections, National Agricultural Library
Artist Charles Steadman painted this watercolor of a Nero apple in 1925. WSU researchers are trying to bring Nero back using cuttings from a ‘lost’ Palouse orchard. Special Collections, National Agricultural Library

He and undergraduate researcher Sonia Weatherly are using the Steptoe scions to propagate new plant material that they can use for grafts. Success means WSU will have a source of germplasm, or genetic materials, for rare varieties, and in a few years, someone may crunch a new Nero.

Reclaiming vanished varieties does more than bring back apples with unusual flavor or color. Lost apples could have valuable traits, such as disease resistance or drought tolerance, just waiting to be discovered.

“You don’t know what might be there that is of value, until you look at it further,” Tarlyn said. “But if you lose the heritage, it’s gone.”