Nav: Home

A lawn is better than fertilizer for growing healthy blueberries

March 12, 2019

Blueberries are prone to iron deficiency - and correcting it increases their health-enhancing antioxidant content, researchers have discovered.

Published in Frontiers in Plant Science, their study shows that growing grasses alongside blueberry plants corrects signs of iron deficiency, with associated improvements in berry quantity and quality. The effects are comparable to those seen following standard chemical treatment - providing a simpler, safer, cheaper and more sustainable strategy for blueberry farming on sub-optimal soils.

What do superfruits eat?

All soils are rich in iron, but nearly all of it is insoluble.

"Most plants get enough iron by secreting chemicals that make it more soluble," explains senior study author Dr José Covarrubias, Assistant Professor of Agriculture Sciences at the University of Chile. "These iron 'chelators' can be released directly from the roots, or from microbes that grow among them, and allow the iron to be absorbed."

"Blueberries, however, lack these adaptations because they evolved in uncommonly wet, acid conditions which dissolve the iron for them."

As a result, most of the world's relatively dry or alkaline ('limey') cropland is unsuitable for optimal blueberry growth.

"Iron is essential for the formation and function of plant molecules like chlorophyll that allow them to use energy," Covarrubias continues. "That's why iron deficiency shows up as yellowing leaves - and drastically reduces plant growth and yield.

"And in blueberries, iron-dependent enzymes also produce the 'superfruit' antioxidants responsible for their celebrated blue skin and health-enhancing effects."

Strong blueberries must pump iron - but at what cost?

There are two approaches to correcting iron deficiency in blueberries: acidify the soil, or add synthetic iron chelators. Each has its drawbacks, says Covarrubias.

"The commonest industrial approach is soil acidification using sulfur, which is gradually converted by soil bacteria into sulfuric acid. The effects are slow and difficult to adjust - and in waterlogged soils, hydrogen sulfide might accumulate and inhibit root growth.

"Acids can also be added directly via irrigation systems for more rapid acidification - but these are hazardous to farmers, kill beneficial soil microbes, and generate carbon dioxide emissions.

"A commoner strategy among growers is application of iron bound to synthetic chelators - often sold as 'ericaceous fertilizer' - but these are very expensive and leach potentially toxic chemicals into the water table."

A cheaper, safer alternative is needed for efficient large-scale blueberry production. Thankfully, one already exists.

"Grasses - which are well-adapted to poor soils - can provide a sustainable, natural source of iron chelators via their roots when grown alongside fruiting plants. Intercropping with grass species has been shown to improve plant growth and fruit yield in olives, grapes, citrus varieties - and most recently, in blueberries."

A grassroots approach to sustainable blueberry farming

Now, Covarrubias and colleagues have brought intercropping a step closer to the mainstream of blueberry cultivation.

For the first time, they measured the effects of different methods of iron chelation on antioxidant content and other fruit qualities in blueberries.

"In an orchard of 'Emerald' blueberry bushes cultivated in alkaline (pH 8) soil, we compared the effects of five different iron chelation treatments: a 'gold-standard' synthetic iron chelator (Fe-EDDHA), intercropping with grass (common meadow grass or red fescue), cow's blood (Fe-heme), or no treatment (control)."

"We found the association with grasses increased not only the total weight and number of blueberries per plant, but also the concentration of anthocyanins and other antioxidant compounds in their skins, compared to control. The effect sizes were comparable with the proven synthetic chelator Fe-EDDHA, whereas applications of Fe-heme from cow's blood - a fertilizer commonly used in home gardens - had no significant effect."

The beneficial effects paralleled improvement in the plants' iron status (leaf color), which was also comparable between the grass-associated and the Fe-EDDHA-treated plants. None of the treatments had a significant effect on average berry weight

Turf is ready to roll out for healthier blueberries

A potential limitation of intercropping observed in the study was a decrease in berry firmness, since firmer berries are favored by consumers.

"The association with grasses decreased berry firmness compared with control plants, whereas the berries collected from plants treated with Fe-EDDHA reached intermediate values.

"However chemical analysis showed a non-significant trend towards increased ripeness in the berries collected from the intercropped plants, which could account for this small difference."

Intercropped plants also required an additional water supply to maintain a similar soil moisture to other treatments, but plant management was otherwise straightforward and the same across groups. The grasses were kept cropped between 5 and 15cm - a typical range for an attractive mown lawn.

"Our findings validate intercropping with grasses as a simple, effective, sustainable alternative to standard iron correction strategies in blueberries," concludes Covarrubias. "Both commercial and private growers can put this strategy to use right away to boost their blueberry crop and antioxidant content."
-end-
Please link to the original research article in your reporting: https://www.frontiersin.org/articles/10.3389/fpls.2019.00255/full

Frontiers is an award-winning Open Science platform and leading Open Access scholarly publisher. Our mission is to make research results openly available to the world, thereby accelerating scientific and technological innovation, societal progress and economic growth. We empower scientists with innovative Open Science solutions that radically improve how science is published, evaluated and disseminated to researchers, innovators and the public. Access to research results and data is open, free and customized through Internet Technology, thereby enabling rapid solutions to the critical challenges we face as humanity. For more information, visit http://www.frontiersin.org and follow @FrontiersIn on Twitter.

Frontiers

Related Iron Deficiency Articles:

Oxygen deficiency rewires mitochondria
Researchers slow the growth of pancreatic tumor cells.
Study finds toolkit could improve detection and management of iron deficiency in pregnancy
Iron deficiency in pregnancy is a common problem that often goes unrecognized and untreated due to a lack of knowledge of its implications and competing clinical priorities.
Study confirms banded iron formations originated from oxidized iron
A new study by University of Alberta scientists shows that banded iron formations originated from oxidized iron, confirming the relevance and accuracy of existing models -- a finding of great importance to the geological community.
Study: Adolescent female blood donors at risk for iron deficiency and associated anemia
Female adolescent blood donors are more likely to have low iron stores and iron deficiency anemia than adult female blood donors and nondonors, which could have significant negative consequences on their developing brains, a new study led by Johns Hopkins researchers suggests.
How plants cope with iron deficiency
Research groups from Heinrich Heine University Düsseldorf (HHU) and the University of Münster (WWU) have discovered a new switch that plants use to control their responses to iron deficiency.
More than just a DNA repair deficiency syndrome
By studying the skin phenotype of the hereditary disease Cockayne syndrome researchers at the IUF and HHU Duesseldorf have found a mechanism which can prevent the loss of subcutaneous fat, i.e. one of the cardinal symptoms of Cockayne syndrome.
Vitamin D deficiency affects many pregnant women
Only one in five women follows the recommendations for taking vitamin D supplements during pregnancy.
Vitamin deficiency in later life
One in two persons aged 65 and above has suboptimal levels of vitamin D in the blood.
New quick, portable test for iron, Vitamin A deficiency could save lives
Cornell University engineers and nutritionists have created a swift solution for a challenging global health problem: a low-cost, rapid test to detect iron and vitamin A deficiencies at the point of care.
Earlier blood testing for iron deficiency, anemia recommended for young women
Physicians should consider blood testing of female adolescents for iron deficiency within a few years of starting menses, according to two studies by Penn State College of Medicine researchers.
More Iron Deficiency News and Iron Deficiency Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#541 Wayfinding
These days when we want to know where we are or how to get where we want to go, most of us will pull out a smart phone with a built-in GPS and map app. Some of us old timers might still use an old school paper map from time to time. But we didn't always used to lean so heavily on maps and technology, and in some remote places of the world some people still navigate and wayfind their way without the aid of these tools... and in some cases do better without them. This week, host Rachelle Saunders...
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.