Tag Archives: agriculture

Urban farming can feed surprisingly many people — at least in Sheffield

Using 10% of a city’s green spaces such as gardens and urban parks could provide the fruit and vegetables to feed 15% of the local population, according to a new study.

Gateway Greening Urban Farm, St. Louis, Missouri.
Image via Wikimedia.

Researchers at the Institute for Sustainable Food at the University of Sheffield analyzed the potential of urban horticulture in feeding Sheffield citizens by mapping its green and grey spaces.

Domestic gardens, allotments, and suitable public green spaces put together would correspond to 98 square meters per person in Sheffield for growing food. Commercial horticulture across the UK currently uses around 23 square meters per person, the paper adds.

Local produce

Green spaces cover around 45% of the city, which is similar to other cities in the UK. Allotments represent 1.3% of this surface, with domestic gardens, which have immediate potential to start growing food, making up 38%.

Using data from Ordnance Survey and Google Earth, the team showed that a further 15% of the city’s green space (such as parks and roadside verges) could also be converted into community gardens relatively easily.

If all the green areas in Sheffield were to be turned over for food production, the team estimates it could provide fruits and vegetables for approximately 709,000 people per year (that number is, currently, 122% of the city’s population). But even if only 10% of available green space is used to grow food, it could provide for 87,375 people, or 15% of the city’s population. The team explains that this would greatly improve the UK’s food security, by increasing the share of locally-grown food in the economy.

The team also analyzed soil-free farming on flat roofs through means such as hydroponics (plants grown in a nutrient solution), and aquaponics (a system combining fish and plants). Such farms would allow year-round growing of food with minimal lighting requirements, and virtually no ecological impact — the greenhouses would be powered by renewable energy and heat captured from buildings, with rainwater harvesting for irrigation. The 32 hectares of flat roof cover in Sheffield would translate to only half a square meter per local, but the team says it could have a significant impact on local food security.

“At the moment, the UK is utterly dependent on complex international supply chains for the vast majority of our fruit and half of our veg — but our research suggests there is more than enough space to grow what we need on our doorsteps,” says Dr. Jill Edmondson, Environmental Scientist at the University of Sheffield and lead author of the study.

“Even farming a small percentage of available land could transform the health of urban populations, enhance a city’s environment and help build a more resilient food system.”

The paper “The hidden potential of urban horticulture” has been published in the journal Nature Food.

New dataset describes 436 possible futures and their climate

The climate emergency doesn’t just mean more emissions but also the need to adapt to a new warmer world, affecting different groups of people, including farmers and their crops. A new 7-terabyte dataset, the largest of its kind, hopes to help us prepare by better envisioning future climate scenarios.

Credit Wikipedia Commons

The Center for Tropical Agriculture (CIAT) and colleagues created the open-access dataset aiming to help policymakers to create adaptation strategies for smallholder farmers. So far, it’s been a resounding success — the data has already been used in 350 research papers in 186 countries and has almost 400,000 downloads so far.

“Climate models are complex representations of the earth system, but they aren’t perfect,” said Julian Ramirez-Villegas, the principal investigator of the project and a scientist with CIAT. “These errors can have an impact on our agricultural models. Because these models help us make decisions, this can have dire consequences.”

Most of the current climate change projections are available at large scales, from 70 to 400 kilometers. But that’s not sufficient for models analyzing the impact of climate in agriculture, which needs much finer scales.

The researchers used a set of techniques to increase the spatial resolution and to correct measurement errors of the dataset, creating high-resolution climate data for up to 436 future scenarios – each one including monthly information for 19 variables such as monthly average temperature and rainfall.

“Through these scenarios, we can understand, for instance, how agricultural productivity might evolve if the world continues on the current greenhouse emissions trajectory,” said Carlos Navarro, a CIAT researcher. “They also provide the data to model what types of adaptations would be needed.”

The dataset has been used mainly for agricultural research, specifically on crops that are significant to food security and incomes such as rice, coffee, cocoa, and maize – all of which are already being affected with climate change.

But other non-agricultural-related projects have also found the dataset to be a valuable resource. For example, it was used to map the potential spread of Zika (a mosquito-borne disease) across the globe, and to predict the decline of skating days in Canada because of warmer winters.

Agriculture and climate change

Agriculture is visibly affected by climate change, putting food security at risk across the globe. But it is also an activity that contributes to global warming because of its high level of emissions.

In order to meet the goals of the Paris Agreement to limit global warming to 2 degrees Celsius, emissions from agriculture have to go down steeply, according to a report by the Intergovernmental Panel of Experts on Climate Change.

In the meantime, farmers are already dealing with the effects of a warmer world. Crop yields are being affected, soils are being degraded, and the occurrence of extreme weather events is increasing. Adaptation and smart agriculture are crucial to deal with such factors in such a way that they do not affect food security.

Saving the bees: Small prairies around agricultural fields can help bees get through the winter

Honey bee pollinating clover. Image credits: Amy Toth

When scientists placed honey bee hives next to soybean fields in Iowa, they were prepared to track how the bees would fare over the season. Surprisingly, the bees seemed to do really well at first. They gained weight, built up honey stores, and thrived. But things quickly turned south in August. By October, the bees had consumed almost their entire stock, and were malnourished.

The reason was simple: they were out of food sources.

“We saw a feast-or-famine kind of dynamic happening, where in the middle of the summer they were doing great. In fact, the hives in highly agricultural areas outcompeted hives in areas with less soybean production,” said Amy Toth, a professor of ecology, evolution and organismal biology at Iowa State University who led the research with ISU entomology professor Matthew O’Neal and University of Illinois entomology professor Adam Dolezal.

“But then they all just crashed and burned at the end of the year,” Toth said.

The researchers tried different approaches to see if they could save the bees. They were somewhat successful when they moved the bee colony to a reconstructed prairie site with many late-flowering plants. This helped the hives rebound and make sufficient stocks for the winter.

This study is particularly important as it offers a nuanced view of how bees tend to do around agricultural areas. Some previous studies have found that honeybees do better in agricultural areas than in other landscapes, but this is still far from settled. What Toth and colleagues show is that bee evolution is not linear — even if they thrive in the summer, yearly can still be devastating.

“There’s been a lot of interest in how bees respond to agriculture,” said co-author Adam Dolezal. “There’s been work on pesticides and predictions that the highly monocultured agricultural landscapes have lost a lot of floral resources.”

“One hypothesis about that is that bees near agricultural zones have more access to flowering crops and weeds like clover than those near forests, which can have fewer floral resources,” he said.

Prairie planting on former agricultural field. Image credits: Cassi Saari.

The new research seems to support this idea — but yet again, things aren’t clear. The researchers tracked to see which plants the bees rely on, so they took samples of pollen spilled by foraging bees. Surprisingly, over 60% of the pollen came from clover — not the agricultural soy plants. Field edges are often mowed and contain clover, which seems to be very important for the bees — but is often neglected by the farmers.

But here’s the thing) clover (as soybean, and many other agricultural plants) tend to bloom in late July or early August. This means that in late August, the bees’ food supply starts dwindling. If we want to help bees make it past the hump, providing them access to a small prairie (particularly consisting of late-blooming flowers) can make a huge difference. However, researchers don’t recommend that beekeepers move their hives around.

That’s difficult, time-consuming, and in many environments, there are few prairies which can support the bees. Instead, the team recommends adding small patches of around 5-8 acres (2-3 hectares) around large agricultural fields.

These strips will not only help the bees, but they would also reduce soil erosion and prevent unwanted nutrient run-off from farm fields into waterways. They would also help other insects and critters, helping to mitigate some of the invariable ecosystem damage brought by agriculture. These prairies would essentially serve as an oasis for life in what is often an agricultural desert.

The study “Native habitat mitigates feast/famine conditions faced by honey bees in an agricultural landscape” has been published in the Proceedings of the National Academy of Sciences.

Agriculture impacts diets of wild mammals, study shows

Expanding agriculture can not only affect the diversity and abundance of wildlife but also alter the diet and habitat of wild mammals, especially those living in fragmented forest areas near crops or pastures, according to new research.

Image credit: Wikimedia Commons.

The study, published in Proceedings of the National Academy of Sciences (PNAS), analyzed how changes that agriculture affect the diet of wild mammals, proving the hypothesis that deforestation and forest fragmentation are not necessarily the main consequences of expanding crops and cattle.

“Forest remnants and the agricultural matrix aren’t separate. There’s an interface between these areas. It’s hardly news that animals need to find food in plantations, but this practice hadn’t been quantified until now. I should stress that the diet in question isn’t ideal. It’s a matter of survival,” said Marcelo Magioli, the lead author.

Magioli and his fellow researchers looked at stable carbon and nitrogen isotopes in the fur of the animals, a method that allows them to know the kind of food eaten in the last three months. They used hair traps and collection of droppings so as not to alter the animals analyzed, many of them threatened with extinction.

They collected samples in four areas of the Brazilian state of Sao Paulo, two near croplands in Campinas and Botucatu and two in conserved areas in stable carbon and nitrogen isotopes. The samples were from 29 species of mammals and of all the samples taken more than half were from animals living in human-modified areas.

“From previous studies using GPS collars and camera traps, we knew the animals moved through these areas,” Magioli said regarding their research. “However, stable isotope analysis told us where they were feeding and how important each food source was in their diet.”

The results showed that 34.5% of the animals fed only with agricultural resources from human-modified areas, while 67.5% survived on forest resources. Frugivores and insectivores ate the same no matter where they lived, while herbivores and omnivores were the most affected, eating mainly agricultural resources.

Species like the cougar, capybara, brocket deer, ocelot and crab-eating raccoon where some of the ones mentioned in the study for having adapted their diets because of the agricultural expansion. The margays, a small wild cat, for example, eat animals that live near sugarcane plantations.

“Our findings point to the need for more favorable agricultural management to support these animals and underscore the importance of the Brazilian Forest Code and of maintaining legal reserves and permanent conservation areas [APPs],” Katia María Ferraz, co-author, said.

Blend solar panels with agriculture, new study recommends

Solar energy is not only compatible with agriculture — it can actually be beneficial.

Image via Wikipedia.

Two of the world’s most pressing challenges are ensuring food security and renewable energy for the globe’s population. At first glance, it would seem that the two don’t play well together. Take solar panels: they produce electricity from solar energy — the same energy which plants need for photosynthesis. So then how could the two work together? According to a new study, it’s possible thanks to an overabundance of solar energy.

Agrivoltaics, which relies on solar sharing, is the idea that solar panels and crops can work well together. The idea has been gaining a lot of traction and interest lately, but few studies have monitored all the aspects of the associated food, energy, and water systems.

“So which land use do you prefer — food or energy production? This challenge strikes right at the intersection of human-environment connections, and that is where geographers shine!” said Greg Barron-Gafford, an associate professor in the School of Geography and Development and lead author on the paper that was published today in Nature Sustainability. “We started to ask, ‘Why not do produce both in the same place?’ And we have been growing crops like tomatoes, peppers, chard, kale, and herbs in the shade of solar panels ever since.”

In order to address this issue, the team lead by Barron-Gafford worked on Biosphere 2 — an American Earth system science research facility located in Oracle, Arizona. Biosphere 2 was originally meant to demonstrate the viability of closed ecological systems to support and maintain human life in outer space, but it has since become a center for research and outreach related to Earth science.

Biosphere 2 is also located in the American Southwest — an area known for its hot and dry weather. Water is a scarce commodity, and things are only going to get worse due to climate heating. No other study has assessed the feasibility of agrivoltaics in such an environment, so it was an excellent place to start. The first problem is location, researchers say.

“Many of us want more renewable energy, but where do you put all of those panels? As solar installations grow, they tend to be out on the edges of cities, and this is historically where we have already been growing our food,” said Barron-Gafford, who is also a researcher with Biosphere 2.

The study focused on chiltepin pepper, jalapeno and cherry tomato plants — regional plants. Three plots were set out for the summer months: one with solar panels, one with crops, and one with both. Throughout the study, researchers continuously monitored incoming light levels, temperature, and humidity using sensors mounted above the surface. They also measured subsurface temperature and moisture at a depth of 5 centimeters. The solar panels were mounted 3 meters high — a bit taller than usual.

The idea wasn’t just that the solar panels and crops could co-exist, but that they could actually help each other. In the torrid Arizona sun, the shade provided by solar panels lowered the surface temperature and reduced evaporation, which helped the crops. Similarly, the plants would help keep the panels just a little cooler, which actually helps produce more electricity (since solar panel efficiency drops with high temperatures).

Air temperatures were on average 1°C cooler during the day on average, but they also stayed about 0.5°C warmer overnight. Meanwhile, the temperature of the solar panels dropped by 9°C due to the plants growing beneath them. This amounts to an increase in efficiency of 3% over the summer months and 1% for the entire year.

As for the plants, the results were simply remarkable.

“We found that many of our food crops do better in the shade of solar panels because they are spared from the direct sun,” Baron-Gafford said. “In fact, total chiltepin fruit production was three times greater under the PV panels in an agrivoltaic system, and tomato production was twice as great!”

Not all plants benefited equally, however, The Jalapeños took up 11% less CO2 under the panels, which suggests that they missed the extra sunlight. However, the jalapeño crops under the solar panels produced just as much as those without solar panels, but they used 65% less water due to reduced transpiration.

The cherry tomatoes saw a 65% increase in CO2 uptake and a 65% increase in water-use efficiency — while producing twice as many tomatoes.

More research is still required on other species, but this study is extremely encouraging. It not only showcases that solar energy and plants can help each other, potentially opening the way for sustainable agrivoltaics facilities. In addition to further research, the team is already working on adding such installations to multiple schools. Getting people more interested in what happens in their community is an important dynamic if we want to implement sustainable shifts in society, he concludes.

“What draws me to this work is what happens to the K-12 learner when their involvement is consequential and the research lives in their community,” said Dr. Moses Thompson, one of the research authors. “That shift in dynamics creates students who feel agency in addressing grand challenges such as climate change.”

Journal Reference: Greg Barron-Gafford et al. Agrivoltaics provide mutual benefits across the food–energy–water nexus in drylandsNature Sustainability, 2019; DOI: 10.1038/s41893-019-0364-5

Essential oils, a novel way to deal with a major pest

When finding their plant hosts, agricultural insect pest always seeks familiar scents. But they can also be repelled by odors from other plant species, according to new research, which offers a new framework for exploiting plant odors to repel insect pests.

Broccoli, one of the affected crops. Credit: Living in Monrovia (Flickr)

 

A team at the University of Vermont worked on the swede midge, a small fly which has become a problem for farmers from the Northeast that work with cabbage-family crops like broccoli and kale. They discovered that a set of essential oils were effective at repelling the midge, such as garlic and spearmint.

“People often think more aromatic plant oils, like mint, basil and lavender will repel insects, but usually there is no rhyme or reason for choosing,” says senior author Yolanda Chen. “It turns out that as we go along the family tree, plants that are more distantly related from the host plant are generally more repellent.”

In order to survive, the small fly feeds on the brassica plant family, which includes a set of popular vegetables such as cabbage and brussels sprouts. If the midge laid its eggs on the wrong plant, it would mean the death of its offspring, according to observations by the researchers.

The midge’s larvae affect the plant’s control system, causing distorted growth – such as brown scarring. But, unfortunately for farmers, they can’t observe the problem until it’s too late and the midge has dropped off the plant. The tiny fly is known to cause crop losses of up to 100% in some areas of the US and Canada.

Trying to deal with the midge, farmers have turned to insecticides, which has been associated with a decline in bees. Organic farmers found no methods and just stopped growing the vulnerable crops. This led to the team at Vermont University to find new methods to control the small fly.

“It’s hard to get away from using insecticides because they’re good at killing insects,” said lead author Chase Stratton, who is now a postdoctoral researcher at The Land Institute in Kansas. “But plants have been naturally defending against insect herbivores for millions of years. Why are we so arrogant to think we can do it better than plants?”

Stratton and her colleagues were able to identify essential oils from 18 different plants that vary in their degree of relatedness to brassica host crops. They hypothesized that oils from plants that are more distantly related to brassicas would have more diverse odors and be more repellent.

They spent time observing how midges acted when facing broccoli plants that had been sprayed with each of the essential oils. The small fly, they discovered, was less likely to lay eggs on broccoli plants that had been treated with essential oils, compared to the untreated plants.

“Biologically, it makes sense that midges would be able to detect and avoid these plants because the similar odors would make it easier for them to misinterpret these plants as hosts, which would be deadly for their offspring,” said Stratton. “For swede midge, garlic appears to be one of the most promising repellents, particularly because certified organic products using garlic are already available for growers.”

Grazing animals drove the domestication of grain crops

Large grazing animals have a strong selective force on plants, certain plants have evolved traits to thrive on pastoral landscapes. In the Himalayas, yaks (such as the one depicted here) were a significant evolutionary driver. Image credits: Robert Spengler.

In the history of mankind, few things have been as influential as domestication. Whether it’s plant or animal domestication, this process has enabled our species to lay the foundation of what we now call society. Having access to a reliable source of nutrients enabled settlements to develop and thrive.

The earliest known human attempts at plant domestication occurred in the Middle East, some 11,000 years ago. However, the domestication of grain plants became much more common 7,000-5,000 years ago, in river valleys and grasslands all around the world. That process was driven by the domestication of grazing animals, a new study concludes.

It’s not exactly surprising. It’s been known for quite a while that many familiar grains have common traits suggesting that they coevolved to be dispersed by large grazing mammals. Essentially, the changes in the plant biomes were driven by changes in animal behavior — which themselves were driven by domestication.

Robert Spengler, director of the Paleoethnobotany Laboratories at the Max Planck Institute for the Science of Human History, and Natalie Mueller, a National Science Foundation fellow at Cornell University, write that the progenitors of small-seeded crops evolved to be dispersed by domesticated animals. They looked at the herbivory patterns and the rangeland these herbivores would have inhabited. Although these wild varieties now only grow in isolated patches, these patches are much more common near rivers or other areas that animals were more likely to frequent. Growing in patches also made harvesting them easier for early human populations.

The study was carried out in North America, where, for a long time, the domestication of plants wasn’t well understood. The missing puzzle piece was bison. As the massive bison herds moved throughout North America, they dispersed these plants in relatively compact areas, leaving a trail of vegetation behind them. But as the European populations slaughtered the bison, the plant populations also started to dwindle.

[Also Read: How megafauna and humans shaped the apple’s domestication]

Bison herds, once dominant across many areas of the US, are now functionally extinct. Image via NPS.

However, this process wasn’t restricted only to North America. Elsewhere in the world, other grazers also helped spread certain plant populations, something which humans took advantage of. As domesticated animals became more and more common, they also played a selective role.

“Small-seeded annuals were domesticated in most areas of the world,” explains Spengler. “So the ramifications of this study are global-scale. Scholars all over the world will need to grapple with these ideas if they want to pursue questions of domestication.”

For decades, researchers have debated why early human foragers preferred small-seeded annual plants as a major food source (which ultimately led to their domestication). The fact that these plants would have been easy to harvest and preferable by animals probably contributed to their ultimate domestication.

Now, researchers want to further analyze this idea and see how other ruminant megafauna contributed to the distribution and domestication of plants all around the world.

“Currently, we’re studying the ecology of fields where modern herd animals graze as proxies to what the ecology would have looked like during the last Ice Age, when large herds of bison, mammoths, and wooly horses dictated what kinds of plants could grow across the American Midwest and Europe,” explains Spengler. “We hope these observations will provide even greater insight into the process of domestication all over the world.”

The study was published in Nature Plants.

Ancient Celts had good taste in their drink, new study shows

A new archaeological analysis maps what the Celts were drinking, finding evidence of wine, as well as beer, milk, and olive oil.

Image credits: Luciana Braz.

In the first century BC, the political situation in Europe was pretty complex. Much of Greek learning was assimilated by the nascent Roman state, and towards the end of the century, the Romans grew to be the most powerful force on the continent, threatened only by Carthage, which was also defeated by the Romans. While they weren’t threatening Roman hegemony, the Celts were also a force to be reckoned with. Their culture is far less understood than that of the Romans, however.

Researchers in the Ludwig-Maximilians-Universitaet (LMU) in Munich and the University of Tübingen wanted to better understand the dietary habits of the Celts of the 1st century BC — particularly what they liked to drink. They analyzed 99 drinking vessels, storage and transport jars recovered during excavations at Mont Lassois in Burgundy — a fortified princely settlement.

Even before the results came in, it was clear that the Celts were involved in active trade with several peoples, especially the Greeks. Like much of Europe, they were enamored with some aspects of the Greek lifestyle and attempted to emulate it.

“This was a period of rapid change, during which vessels made in Greece and Italy reached the region north of the Alps in large numbers for the first time. It has generally been assumed that this indicates that the Celts began to imitate the Mediterranean lifestyle, and that only the elite were in a position to drink Mediterranean wine during their banquets,” says LMU archaeologist Philipp Stockhammer, who led the project.

This type of shard was analyzed in the study. Image credits: Victor S. Brigola.

Traces of liquids were absorbed by the ancient pots, where they were stored throughout the centuries. Researchers were particularly looking for traces of wine: a drink which wouldn’t have been traditional for the Celts, but was already a staple around the Mediterranean. Finding evidence of wine consumption would confirm that the Celts were, in fact, adopting the lifestyle from the Greeks.

This turned out to be the case. Cynthianne Spiteri adds:

“We are delighted to have definitively solved the old problem of whether or not the early Celts north of the Alps adopted Mediterranean drinking customs. – They did indeed, but they did so in a creative fashion!”

What Spiteri is referring to is the fact that Celts didn’t take things as they are from Greece. For instance, in addition to wine, they also drank local beer from Greek drinking bowls. Significantly, wine consumption wasn’t limited to the posh population of the Celts — the middle class also enjoyed a glass from time to time.

“In other words, the Celts did not simply adopt foreign traditions in their original form. Instead, they used the imported vessels and products in their own ways and for their own purposes. Moreover, the consumption of imported wine was apparently not confined to the upper echelons of society. Craftsmen too had access to wine, and the evidence suggests that they possibly used it for cooking, while the elites quaffed it in the course of their drinking parties. The study shows that intercultural contact is a dynamic process and demonstrates how easy it is for unfamiliar vessels to serve new functions and acquire new meanings.”

Researchers also found other types of drinks, confirming that most if not all layers of the Celt society were consuming a remarkable array of drinks — alcoholic and non-alcoholic.

“We identified characteristic components of olive oil and milk, imported wine and local alcoholic beverages, as well as traces of millet and beeswax,” says Maxime Rageot, who performed the chemical analyses in Tübingen.

Journal Reference: Rageot et al. New insights into Early Celtic consumption practices: Organic residue analyses of local and imported pottery from Vix-Mont Lassois. PLOS ONE, 2019; 14 (6): e0218001 DOI: 10.1371/journal.pone.0218001

 

Nitrate pollution in US tap water causes 12,500 cancers each year

A concerning new study finds that nitrate, largely coming from farm fertilizer and manure, is responsible for 12,594 cases of cancer a year in the US.

Around 80% of these cancers were colorectal.

The concentration of nitrate (NO3) has steadily increased in many countries, especially due to farm runoff containing fertilizer and manure. Naturally, agricultural areas are more exposed than others, although intensive agriculture and more aggressive land use have increased the concentration of nitrates over surprisingly large areas.

In countries like the UK or the Netherlands, nitrate concentrations in groundwater are steadily increasing year after year, sometimes reaching dangerous levels. The US is no exception.

Nitrate is one of the most common groundwater contaminants in rural areas of the US. The current federal drinking water standard for nitrate, set in 1962, is 10 parts per million (ppm). The Environmental Protection Agency has considered updating this limit, particularly as some studies have suggested that even a fraction of that limit could have negative health impacts, but the talks were suspended earlier this year.

Humans are subject to nitrate toxicity, with infants being especially vulnerable. Nitrates react with amines and amides in the human body to produce N-nitroso compounds (NOC), which are known to cause cancer in animals and may cause cancer in humans. The largest source of nitrates is from certain types of vegetables which are naturally high in nitrate — however, these vegetables also contain compounds that prevent the formation of NOCs, so these vegetables are not associated with a higher cancer risk (eating vegetables is actually associated with a host of health benefits not related to nitrates).

Instead, studies have found connections between cancer and high nitrate concentration in drinking water. In the new study, researchers from the Environmental Working Group (EWG, a non-profit that specializes in agriculture-related research) quantified how much of an impact the excess nitrate is having.

“Millions of Americans are being involuntarily exposed to nitrate, and they are also the ones paying the heavy costs of treating contaminated tap water,” said Alexis Temkin, Ph.D., a toxicologist at EWG and primary author of the study. “But the federal government is not doing enough to protect Americans from tap water contamination.”

They found that the level at which there would be no adverse health effects was at 0.14 parts per million — 70 times lower than the current risk. At that level, there would be a one-in-a-million risk of cancer. Meanwhile, the team estimates that the current level is responsible for 12,500 cancer cases, as well as 2,939 cases of very low birth weight, 1,725 cases of very preterm birth, and 41 cases of neural tube defects.

In addition to the health hazards, all these issues incur treatment costs of up to $1.5 billion a year.

Researchers stress that this is not a trivial result, and measures should be taken to reduce the impact of this agricultural pollution.

The study was peer-reviewed and published in the journal Environmental Research.

Plant on dry soil.

Researchers hack plants to use less water so we don’t starve when climate change hits hard

Researchers are getting ready for the mother of all dry spells — by making plants require less water to grow.

Plant on dry soil.

Image via Pixabay.

Anthropic climate change is already barring its fangs at us, and they are dry indeed. A preview of what’s in store is recently unfolded in Cape Town, South Africa. The Western Cape region of South Africa has been experiencing severe droughts since 2015, and because of that, the city is realistically looking at a Day Zero scenario — a day where the municipal water supply will be dry as bone.

That situation could become common in many parts of the world, at least until water cycles set down into their new mold. Until then, it’s vital that we ensure there’s enough water for everyone to drink. A team of researchers from the University of Illinois, Urbana are trying to reduce the amount of water we use on our crops. In a new paper, they report having genetically engineered a prototype tobacco crop that uses 25% less water for essentially the same harvest.

“We tested them in the field and we didn’t see a big penalty — the plants were not significantly smaller than the wild type,” said lead researcher Katarzyna Glowacka.

They quenched the plants’ thirst by modifying the expression of a protein involved in the behavior of stomata — small pores on the leaves of plants that take in CO2 and spew out oxygen and water. Lab experiments showed that greater expression of the protein (called Photosystem II Subunit Subunit S, or ‘PsbS’) restricted stoma’s ability to open, keeping water inside the plant’s cells without affecting the intake of CO2. After some time tweaking around with PsbS expression, the team managed to spike the prototype tobacco’s water efficiency by 25%. Tobacco is widely used as a model plant for similar studies because its fast lifecycle means researchers don’t have to wait around for it to grow very long.

“Our next step is to look at C4 crops […] like corn, soy bean, sugarcane, sorghum,” says Dr Glowacka.

“In tobacco it works and it should work the same way in other plants. In C4 plants, which are most [food] yielding plants like corn and sugarcane, it has even bigger promise.”

The C4 plants that Dr. Glowacka mentions are better at fixing CO2 during photosynthesis than most other crops and the researchers think their stomata can be manipulated to a greater extent that the prototype tobacco because of this.

However, the current research was carried out in controlled environments, where the plants were given plenty of water and sunlight. More extensive studies are needed to assess the potential of this approach in real-world scenarios, especially trials in free range conditions.

Still, for now, the findings hold great potential for the future. The challenge is to produce a lot more food than we do today, without a sizeable increase in land or water use — because we simply don’t have much to spare of either of those.

The paper “Photosystem II Subunit S overexpression increases the efficiency of water use in a field-grown crop” has been published in the journal Nature.

Pests destroy around one quarter of our crops — even more in developing areas

If we want to be able to feed the world, we’d best pay closer attention to pests.

According to current estimates, the world population is 7.7 billion. It took over 200,000 years to reach the first billion, and only 200 more years to reach 7.7 billion. By 2100, even conservative estimates put the world population at 11 billion — all of which will have to be fed. Considering that today, over 800 million suffer from chronic undernourishment, feeding the population of tomorrow will be quite a challenge.

Our agricultural productivity has increased dramatically in the 20th century, in a period often called “the Green Revolution.” Norman Borlaug, the “father” of the Green Revolution and the most prominent scientist associated with the movement, is credited with personally saving over 1 billion lives through his work.

However, with no other such revolution in sight, we will need to optimize production and reduce losses as much as possible — and one of the most important problems to consider are pests.

Pests and pathogens are an integral part of agriculture. They’ve been around since mankind has been growing crops, coevolving with agricultural plants. However, that’s not to say that we can’t do anything to fight them. Different methods have been employed, with varying degrees of success. But before we can talk about large-scale campaigns against pests, we first need to understand the big picture.

This is exactly where the new study comes in. Serge Savary, a researcher working at the French National Centre for Scientific Research, and colleagues, took on the gargantuan task of measuring global crop losses caused by pests and pathogens. They focused on the five most popular crops: wheat, rice, maize, potato, and soybean. Together, these crops make up almost half of mankind’s calorie consumption.

They found that at a global level, pets destroy:

  • 21.5% of wheat crops;
  • 30% of rice crops;
  • 22.5% of maize crops;
  • 17.2% of potato crops; and
  • 21.4% of soybean crops.

This type of data is extremely valuable, especially as standardized information is difficult to compile across different regions and crops — and there is little in the way of good news.

All in all, almost one-quarter of this food is completely lost — and to make matters even worse, the highest losses are associated with regions with fast-growing populations and which are already struggling with malnutrition. These are also areas frequently hit by emerging or re-emerging pests and diseases.

Researchers hope that their work will serve as a guideline for policymakers and farmers alike. At a global scale, if we want to be able to feed the world, we need quick and efficient interventions in these areas.

There’s also another problem, a common culprit: climate change. It’s clear that climate change will affect plant-pathogen interactions, but it’s much less clear in what way. While they did not study this directly, Savary and colleagues quote another study, which ultimately concludes that “climate change will bring, above all, surprises.” Quite likely, they won’t be pleasant surprises.

The study has been published in Nature. DOI: 10.1038/s41559-018-0793-y

Plant roots may hold the key to the next generation drought-resistant crops

If we want to feed the world, we’d better pay attention to root architecture, not just the upper half of the plant, researchers warn.

A freesia’s root architecture helps the plant store food to survive seasonal weather conditions. Image credits: Brian Atkinson.

In the past decades, the developed world has been spoiled: not only do we have access to an essentially unlimited supply of food, but the variety and year-round diversity are also unprecedented. There’s also more food overall — the world produces 17% more food per person today than 30 years ago, even considering a significant population growth. But as the population continues to grow and climate change continues to take its toll, feeding the world might become more problematic.

Naturally, scientists are working on ways to improve crops and plant varieties, by tweaking their genes, the pesticide use, and even improving the surrounding soil. But if you ask a group of Nottingham researchers, they’ll likely tell you that the solution lies beneath the ground — in the plants’ roots.

‘You could argue that for the last 10,000 years, we have selected crop varieties on the basis of the upper half, and not focused on this hidden part of crops,’ said Malcolm Bennett, professor of plant science at the University of Nottingham, UK. ‘If we could select new crop varieties based on root architecture, we could significantly improve their ability to forage for water.’

The most visible effects of drought are seen in the overground components, particularly in leaves, but the hidden half is just as important — if not even more so. Roots provide anchorage to all plants, absorb water and nutrients from the soil and store food for the plant. When there’s not much water around, roots can grow deeper to suck water from further underground. If nutrients are sufficient towards the surface, shallow roots grow denser.

It’s easy to understand why roots are relatively understudied: they’re beneath ground, which makes them much more difficult to study. In order to overcome that, Bennett and colleagues used an X-ray micro-computed tomography (micro CT). It’s a technique commonly used in human medicine, but Bennett’s machine is a colossus — 3-4 times larger than a typical medical scanner, allowing them to image living roots in great detail.

Maize develops from a single kernel from which both the stem and earliest roots grow. The root system grows around a primary root supported by smaller lateral roots. As the plants grow older, aboveground brace roots sprout and become the main source of nutrients and water. Image credits: Brian Atkinson.

Because plants can withstand more X-ray radiation than humans, the resolution is also improved, allowing researchers to image even the thinnest of roots. Furthermore, scanning can be done repeatedly to monitor changes. In total, over 8,000 X-ray snaps were taken, with computer algorithms stitching them together to develop an incredibly detailed 3D image.

Among many other plants, the team used this approach to scan hundreds of varieties of wheat to see how they respond to stress. The results were surprising.

‘We noted something fascinating. Plants that were most efficient at using water changed the angle of their roots when you applied drought stress,’ said Prof. Bennett. ‘Steeper rooting angles allowed them to forage for deeper sources of water.’

Prof. Bennett also said that recently, they identified master genes that control root angle in maize and rice. This root angle is extremely important in water absorption, which in turn affects how plants manage dry spells.

‘To maintain wheat yields here (in the UK), we need to have new varieties with roots that grow an extra half metre at least,’ Prof. Bennett explained. Other parts of Europe are similarly concerned about water shortages and its effect on crops.

‘We could optimise crop root systems to take up nutrients more efficiently, such as selecting deeper rooting varieties to capture nitrogen as it moves deeper into soil,’ said Prof Bennett. ‘The idea of selecting new varieties based on root architecture is gaining support amongst breeding companies and researchers.’

Sugar beet grows around a main tap root which stores the sucrose harvested for sugar. The cells dyed green, as viewed under a microscope, form the cortex of the plant, where nutrients and sucrose are stored. Image credits: Brian Atkinson.

Dr. Christophe Maurel, plant scientist at the National Center for Scientific Research (CNRS), says that these findings could also be useful in the case of another very important crop: maize. Maize can be susceptible to drought in Europe because it flowers in summer, unlike wheat, which flowers earlier.

But there’s also a downside to having roots that suck up more water.

‘The more vessels at the root tips, the more susceptible they were to invasion by soil bacteria,’ Dr. Maurel said, meaning there is a trade-off between a better ability to withstand drought and vulnerability to infection.

Maurel also highlights that in a way, scientists are almost in an arms race with global warming — drawing conclusions is not something that can be done immediately, and it will be a while before results go from the lab and onto agricultural fields — but in the meantime, temperatures continue to rise.

 ‘We might help breeders not in five years, but maybe 10 to 20 years,’ he said. ‘Anyway, in 10 to 20 years we will be facing even stronger challenges with drought and climate change.’

Insect damage to crops will drastically increase due to climate change

As if we didn’t have enough problems with climate change, here’s a new one: it will favor crop-devouring pests, bringing more agricultural damage in the coming years.

A modern plague

As anyone working in agriculture will tell you, pests can be absolutely devastating. Already, pests are eating the equivalent of 1 in every 12 loaves of bread, but things are about to get much worse. In a new study published in Science, researchers analyzed the effect climate change has on insects — particularly, pests. They found that rising temperatures accelerate the metabolism of these insects, prompting them to eat more and grow their populations. In other words, future bugs will be hungrier and more numerous.

They started with robust climate projection data, working on the assumption that there will be a 1.7C-2C global warming by the end of the century — a likely scenario, even if all the countries in the world achieve their Paris-mandated agreements (something which certainly isn’t a guarantee). They used crop yield statistics to see how much damage bugs are currently causing and worked on insect metabolic rates and other biological information to see how rising temperatures will affect the insects and, consequently, crops.

They found that results are not uniform, and areas with temperate climates (like most of Europe) will be hit the worst. By the end of the century, eleven European countries are predicted to see 75% or more in insect-induced wheat losses. The U.K., Denmark, Sweden, and Ireland are among those most affected.

“In some temperate countries, insect pest damage to crops is projected to rise sharply as temperatures continue to climb, putting serious pressure on grain producers,” said Joshua Tewksbury, co-lead author of the research and a director of Future Earth, an international research network for global sustainability.

Global problems

North America and Asia won’t be spared. The US, currently the world’s largest maize producer, could suffer a 40% increase in insect-induced maize losses under current climate warming trajectories — and even more if temperatures rise over 2C. This translates to losses of over 20 million tons annually. Meanwhile, one-third of the world’s rice production comes from China, where future insect-induced losses could top 27 million tons annually.

“On average, the impacts on insects adds up to about a 2.5 percent reduction in crop yield for every degree C increase in temperature – for context, this is about half the estimated direct impact of temperature change on crop yields, but in north temperate areas, the impact of increases insect damage will likely be greater than the direct impact of climate on crop yields” said Tewksbury, who is also a research professor at CU Boulder.

The study advises crop growers to start adapting, and consider selecting for heat and pest-resistant crops, as well as new crop rotation patterns. They also warn that, in some areas, greater pesticide use may become necessary to ensure food security — even considering the possible associated health and environmental damage.

The study was published in Science.

If the whole world ate like America, we wouldn’t have enough land in the world

If the entire world adopted the North American dietary guidelines, there just wouldn’t be enough land to support us all, a new study reports.

If you’re reading this article, the odds are you’re from America, Europe, or Australia (the tech guys tell me that’s where most of our visitors are from). But if you do the math, the population of those three areas hardly add up to one billion people — and the world has several billion more. Whether or not they read science websites like our own is hardly the difference between these two groups — they have different cultures, different lifestyles, and even different eating habits.

Like many other things, the Western Diet is dramatically overrepresented in the media — so much so that we’d forgive you for thinking that the entire world eats this way. But that couldn’t be further from the truth. In fact, not only is it not true — it would simply be impossible. If the whole world ate like America, for instance, we wouldn’t have enough land.

“The data shows that we would require more land than what we have if we adopt these guidelines. It is unsustainable,” said Prof. Madhur Anand, director of the Global Ecological Change and Sustainability lab where the study was undertaken. “This is one of the first papers to look at how the adoption of Western dietary guidelines by the global population would translate into food production, including imports and exports, and specifically how that would dictate land use and the fallouts of that,” she said.

According to a new paper by Anand and colleagues, if the globe stuck to United States Department of Agriculture (USDA) guidelines, we would require an additional one giga-hectare of additional land, which is about the size of Canada, the second largest country in the world.

It’s a bit ironic, considering that current dietary guidelines are largely seen as an improvement over the traditional land-intensive diet of the average American, but this just goes to show how much more room for improvement there still is — for America and, likely, most of the developed world.

“We need to look at diet not just as an individual health issue but as an ecosystem health issue,” said Anand, a professor in U of G’s School of Environmental Sciences (SES).

A western/eastern hemispheric divide in land spared versus land required by a USDA guideline diet.
Land spared or required in 2010 by country, in millions of hectares (MHa). According to the scale, countries that would reduce global land use by changing to a USDA guideline diet (net positive land spared) are indicated in blue and teal, while countries that would require extra land to meet the guidelines (net negative land spared) are indicated in red, yellow or green. Image credits: Rizvi et al / PLoS ONE.

However, the US itself is not the biggest offender. In fact, most Western Countries use more land per capita, researchers say, while the rest of the world uses much less. There’s a big East-West divide, but the country which uses the least land per capita is Africa — unsurprising, given that much of the continent is still undernourished and underdeveloped.

The researchers also make a simple but very important plea: let’s make some global, general dietary guidelines.

It makes a lot of sense — after all, land is a strictly limited resource, and our dietary preferences directly influence how much land we use. If we tried to coordinate our efforts globally, much like the global movement to reduce greenhouse gas emissions, it could work out for the benefit of everybody.

“Global food security and agricultural land management represent two urgent and intimately related challenges that humans must face,” the study reads.

That idea, while laudable, is still nothing more than an idea, and without heavy political support, it’s unlikely that it will take wings in the near future.

Journal Reference: Rizvi et al. “Global land use implications of dietary trends.”

Butcher.

Study weighs environmental costs of producing animal proteins so you know what to buy

Our food choices help shape the environment around us. A new study looks at how livestock, farmed seafood, and wild-caught fish compare in the environmental impact department — so we know exactly what our choices of animal protein entail.

Butcher.

Image via Public Domain Pictures.

The study’s authors call it the most comprehensive look at the effect different types of animal protein production have on the environment. While the rating depends on exactly which criteria you’re looking at, in general, industrial beef production and farmed catfish are the most taxing on the environment, while small, wild-caught fish and farmed mollusks like oysters, mussels and scallops have the lowest environmental impact, they report.

What to eat

“From the consumer’s standpoint, choice matters,” says lead author Ray Hilborn, a professor in the School of Aquatic and Fishery Sciences at the University of Washington.

“If you’re an environmentalist, what you eat makes a difference. We found there are obvious good choices, and really obvious bad choices.”

The team drew their data from previously-published life-cycle assessments for various types of animal protein production. The dataset included hundreds of papers penned throughout the last decade. This type of assessment is also known as a ‘cradle-to-grave’ analysis, as it accounts for a product’s environmental impact during every stage of its life. The team started with over 300 papers assessing animal-associated food production, which they whittled down to 148 studies that were comprehensive enough for the team’s purpose without being focused on a too-narrow subject.

Each type of animal food production was broadly analyzed through the prism of four metrics: energy use, greenhouse gas emissions, potential to contribute excess nutrients to the environment (such as fertilizers), and each’s potential to emit substances that contribute to acid rain. The present analysis also included other environmental impacts such as water demand, pesticide use, antibiotic use, and soil erosion. However, as they were only addressed in some of the studies the team drew on, the team didn’t use them as overarching points of comparison.

Production methods analyzed include aquaculture (farmed seafood), livestock farming, and wild-capture seafood. To make the environmental impacts easily relatable, they were calculated for the daily recommended serving of protein,  40 grams (1.4 oz), across all food types, where data permitted.

Meat me halfway

All in all, the paper found some stark differences in the impacts associated with different types of animal protein. Certain production methods are just better from an ecological standpoint — across all measures. Farmed shellfish and mollusks, as well as wild-capture sardines, mackerel, and herring show some of the lowest ecological footprints. Wild-capture whitefish like pollock, hake, or cod, also had relatively low environmental impacts, as did farmed salmon.

Livestock farming scored strongly for energy use, even better than most types of aquaculture. For example, catfish, shrimp, and tilapia aquaculture consume a lot of energy, since they require constant water circulation — which means constant energy use.

Mollusk (oysters, mussels, or scallops, for example) aquaculture scored high on nutrient leaks — these animals actually absorb excess nutrients in the ecosystems, helping to insulate them from fertilizer pollution, for example. Beef production, on the other hand, rated very poorly here, since the waste winds up in waterways. Capture fisheries scored better here than aquaculture or livestock — it doesn’t require any fertilizer.

Livestock farming scored poorly in the acid rain category because of methane emissions associated with their rearing. Catfish aquaculture and beef production release 20 times more greenhouse gases than small capture fisheries, mollusk, salmon or chicken farming. Farmed mollusks rated the highest here, followed by small capture fisheries and salmon aquaculture. Capture fisheries fell behind in the emissions department due to the high fuel consumption associated with sending vessels out to sea. Small schooling fish like herring and anchovy uses the least fuel, but pot fisheries for lobster use lot of fuel and thus have a high impact per unit of protein produced. Trawling (dragging nets through water) has a variable impact, mostly dependent on the availability of fish stocks.

Quite surprisingly, the paper finds that a selective diet of aquaculture and wild-capture fish has a lower overall environmental impact than vegetarian or vegan diets (as calculated in previous studies). One metric the team didn’t include in their study is how each production method impacts biodiversity — but they plan to factor it in in the future.

“I think this is one of the most important things I’ve ever done,” Hilborn said. “Policymakers need to be able to say, ‘There are certain food production types we need to encourage, and others we should discourage.'”

The researchers advise that consumers decide what environmental impacts are most important to them, then use the results to select what they put on the plate.

The paper “Choice matters: The environmental costs of producing meat, seafood” has been published in the journal Frontiers in Ecology and the Environment.

Emiliana huxleyi

Humanity has contended with rising seas before — and it didn’t go well for us

Some 7,600 years ago, human civilization in Southeastern Europe suddenly came to a halt. New research sought answers as to why this happened, and the findings paint a stark reminder of the toll rising seas can inflict on our society.

Emiliana huxleyi

Coccolithophore Emiliana huxleyi.
Image credits Jörg Bollmann.

The Neolithic revolution was the first major transformation humanity had paused — the transition foraging to farming. Spreading out from the Middle East, this wave of change took peoples used to hunt and forage wherever they pleased and tied them down, hoe in hand, to sedentary — but oh so lucrative — farms and fields.

Can’t till the sea, though

Around 7,600 years ago, however, the revolution paused — no new agricultural settlements seemed to pop up in Southeastern Europe around the time, existing communities declined, and the progress of civilization as a whole came to a standstill. Up until now, we didn’t have any inkling as to why this happened, but new research from the Senckenberg Biodiversity and Climate Research Centre, the Goethe University in Frankfurt, and the University of Toronto sheds some light on this mysterious period.

According to their findings, this lull in progress was due to an abrupt rise in sea levels in the northern Aegean Sea. Evidence of this event was calcified in the fossils of tiny marine algae preserved in seafloor sediments.

The impact this event had on societal dynamics and overall development during the time highlights the potential economic and social threats posed by sea level rise in the future, the team says. Given that climate-change-associated changes in sea level are virtually unavoidable, the team hopes their findings will help us better prepare for the flooding ahead.

“Approximately 7,600 years ago, the sea level must have risen abruptly in the Mediterranean regions bordering Southeastern Europe. The northern Aegean, the Marmara Sea and the Black Sea recorded an increase of more than one meter. This led to the flooding of low-lying coastal areas that would have been ideal areas for settlement,” says lead author Professor Dr. Jens Herrle.

The findings are based on a sediment core retrieved from the sea floor of the northern Aegean Sea. Herrle and his team used this core to reconstruct salinity levels in this part of the Mediterranean from 11,000 and 5,000 years ago. However, the core was also rich in tiny, calcified fossils of Emiliania huxleyi, a coccolithophore (a species of photosynthesizing plankton that’s ubiquitous even today).

Analyzing them under a scanning electric microscope, the team observed significant size changes in these algae — which indicate a change in the salinity of surface water in the Aegean during their lifetime.

“These calcifying algae evidence two rapid decreases in the salt content, at approximately 8,400 and again 7,600 years ago, which can only be explained by the fact that a higher volume of low-saline surface water flowed from the Black Sea into the northern Aegean at these times,” Herrle explains.

Such a rapid rise in sea levels would need a source, and the team says, surprisingly, it can be traced back to North America:

“The source of this may have been Lake Agassiz in North America. This glacial meltwater lake was enclosed in ice and experienced a massive breach during this period, which emptied an enormous volume of water into the ocean.”

The evidence supports a link between the two timeouts in the Neolithic revolution and the flooding events. The event 8,400 years ago coincides with archaeological findings suggesting that settlements in low-lying areas were under significant hardship from encroaching seas and other associated climatic changes. The renewed rise just 800 years later likely amplified these communities’ woes, keeping them from making the transition to agriculture.

Past fluctuations in sea levels have already had a significant effect on human history during the early days of agriculture, the authors note, warning that it would be unwise to dismiss the challenges it will place in our path in the future.

“Due to climate change, we expect global sea levels to rise by up to one meter over the next 100 years,” Herrle adds. “Millions of people could thus be displaced from coastal regions, with severe social and economic consequences.”

The paper “Black Sea outflow response to Holocene meltwater events” has been published in the journal Scientific Reports.

Researchers create the ‘crop hotspot’ map of Mars so we know where to settle

We may not be on Mars yet, but new research has made sure that when we get there, we’ll know exactly where to settle.

Mars Map.

You don’t know this yet but those blue areas? They mean food!
Image credits Wieger Wamelink, Line Schug / Wageningen University & Research

What would life be without food? Well, for starters, really short; but also quite unpleasant. Precisely because of that, colonists going to Mars in the future will need to settle in a place that’s good for agriculture — as good as can be, on a planet with almost no atmosphere.

To their aid comes a study from the Wageningen University & Research, which has identified the areas on Mars which are favorable for the growing of plants. Even though the crops will be grown indoors, local factors still play a part — chief among them being the presence of regolith and ice deposits, both of which will be used to sustain the crops.

Mars’ cropspots

In order to estimate which areas of the planet would be most suitable, the team combined data on Martian geography and geology to create a 3D, Mars-wide landing map, showcasing the best spots for agriculture. The datasets included information about mineral content — relating to calcium and heavy metal content in the soils, for example. Other important element ‘maps’ were those for potassium, chloride, iron, and silicon. The team also mixed in data pertaining to climate, terrain altitude, and radiation exposure.

That’s a lot of data, and several scientific bodies — including the JPL, the Arizona State University, and NASA — pitched in.

“Without them this endeavour would not have been possible”, says Wieger Wamelink, one of the two researchers who created the map.

That’s because each of these elements has a hand to play in the suitability of each area for agriculture. They needed all this data to control for as many factors as possible — and any missing piece could have drastically reduced the work’s applicability. All the maps were merged and, based on the data each contained, were used to calculate a ‘score’ for every area — with high scores marking the best sites, just like in a video game.

Some factors, naturally, were more decisive than others:

“High levels of heavy metals in the soil and strong radiation make a location unsuitable for establishment,” explains Line Schug.

The map revealed that the Mars Pathfinder and Viking 1 landed at ‘hotspots’ for colonies, while the MSL Curiosity and Viking 2 crafts landed on less favorable spots.

The research is part of the larger “Food for Mars and Moon” project unrolling at Wageningen. It aims to develop a sustainable agricultural system that we can take with us to space. The most important element it relies on is the presence of soils and water, both on Mars and the moon.

The first experiments in the project started in 2013. Researchers used soil simulats supplied by NASA — from a volcano in Hawaii (Mars) and a desert in Arizona (moon) — to try and grow crops. At first, the results weren’t very encouraging. But today the team can grow over a dozen crops. The only species that has stubbornly refused to take the plunge to space-soils is spinach. Chemical analysis showed that the plants are safe for human consumption, but there were fears that the plants would accumulate heavy metals more readily than in Earth soils — that’s why this factor was given more importance when creating the agricultural potential map of Mars.

After they were tested, the veggies were cooked and served to those who supported the project via its crowdfunding campaign. I imagine the attendees considered the food to be “stellar” and “out of this world”.

Using rocks for farming could improve soil quality, reduce CO2 emissions

Adding minute rock pieces to soils can release important soil nutrients and also suck up significant quantities of carbon dioxide.

Destruction and rebirth

Fields of green: volcanic soils often host rich, lush vegetation, as can be seen in this photo of Oahu. Image credits: Jason Jacobs / Flickr.

Since the dawn of mankind, humans have tried to find ways to improve agricultural yield — a goal still sought after today. With the global population set to reach 9.7 billion by 2050, researchers are looking for better ways to safely feed the world. Now, an innovative study by University of Sheffield researchers reports an unexpected way through which we can improve production, while also helping reducing carbon dioxide emissions: using rocks as fertilizers.

The idea is that adding fast-reacting silicate rocks to croplands could capture CO2 and give increased protection from pests and diseases. In time, this process would also restore soil structure and fertility, protecting against erosion.

Professor David Beerling, lead author of the research, explains.

“Human societies have long known that volcanic plains are fertile, ideal places for growing crops without adverse human health effects, but until now there has been little consideration for how adding further rocks to soils might capture carbon.”

Volcanic eruptions can be devastating — they destroy everything in their wake, burying surroundings in a blanket of hot ash. But in the long term, volcanic deposits can develop into some of the richest agricultural lands on earth. Take the soils in Italy, for example. The southern parts of the country feature dry, limestone-rich soils. But if you move towards the north, particularly around Naples, the soils are much more fertile — largely due to the eruptions of Mount Vesuvius. Similarly, volcanic areas like New Zealand or Hawaii often feature rich, lush vegetation.

This isn’t anything new. What Beerling is proposing, however, is taking crushed, small carbon-rich rocks (such as basalt) and using them to fertilize agricultural soils. As these minute pieces dissolve in the soil, they would take in carbon dioxide and eliminate nutrients.

The destruction once caused by volcanoes could be used to inject new life into soils.

Two birds with one stone

“The magnitude of future climate change could be moderated by immediately reducing the amount of CO2 entering the atmosphere as a result of energy generation. Adopting strategies like this new research that actively remove CO2 from it can have a massive impact and be adapted very quickly,” Beerling adds.

Of course, this could be applied to all types of soils for the purpose of absorbing CO2, but to take full advantage of the process, it would be best applied over arable land. This would not only absorb CO2 but also improve soil quality and reduce the need for pesticides.

The good thing about this approach is that it would work with a wide variety of rocks — the more calcium-rich, the better. However, the fastest weathering volcanic rocks are not suitable, Beerling told ZME Science in an email.

“The approach work would work best with basic silicate rocks, richer in magnesium and calcium, that weather faster and therefore capture more CO2. But as we point out the paper, the fastest weathering basic rocks — called ultramafics – are typically enriched in metals that can be toxic so you wouldn’t want to use them on croplands.”

Even better, many areas already spread crushed limestone over arable land to reverse acidification of soils caused by farming practices, including the use of fertilizers. So the machinery and infrastructure for the practice already exists — all that needs to be done is change the rock type.

“Crushing technology is common in the mining industry,” Beerlong added in our correspondence. “The size is the particles is a crucial determinate of the rate of chemical reactions. Small particles with a high surface area react faster. Limestone — essentially calcium carbonate — reacts very fast but more often than not releases carbon dioxide rather than sequesters it.”

Professor Stephen Long at the University of Illinois Champaign-Urbana, and co-author of the study, commented:

“Our proposal is that changing the type of rock, and increasing the application rate, would do the same job as applying crushed limestone but help capture CO2 from the atmosphere, storing it in soils and eventually the oceans.”

Long also notes that people don’t understand the full extent of climate change, and scientists haven’t been truly effective in communicating these issues. He added:

“Global warming is a problem that affects everyone on the planet. Scientists generally have done a poor job of getting across the point that the world must reduce emissions of greenhouse gases from fossil fuels and combine this with strategies for extracting carbon dioxide from the atmosphere to avoid a climate catastrophe.”

The research focus now is to see how much carbon dioxide the approach would capture, how much rock is required, and how much energy is required to crush and distribute the rock, researchers say. They also want to assess the long-term impact the treatment has on soils and watercourses.

 

Farmer toy.

Europe’s first farmers mingled with the locals, slowly mixing the communities together

Early farmers didn’t move in and replace hunter-gatherers from the get-go, new research has found. Instead, the two coexisted and interacted for some time after early farmers spread across Europe.

Farmer toy.

Image credits Erika Wittlieb.

The agricultural revolution is one of the most hotly debated turning points in human history. In Europe, the shift from foraging and hunting to a more sedentary, farming lifestyle started around 10.000 years ago. It would culminate in farmers largely replacing pre-existing hunter-gatherer communities.

‘How do you do’ or ‘I’m gonna stab you’?

Previous studies of ancient DNA have shown that the agricultural revolution in Europe wasn’t based on a flow of ideas. Rather, the spread of farming throughout the continent was owed to farmer populations from the Near East expanding into the continent and bringing the practice along with them. Finding a single point of origin for early farming populations throughout Europe was an unexpected discovery, given how diverse prehistoric cultures were in this area.

However, the intricacies of this process are still poorly understood. For example, we don’t really know if it was a peaceful transition, one done at scythe-point, or one aided by disease. In other words, whether newly-arrived farmers would displace the people already living in Europe through war and disease, or they simply co-existed with and out-competed them over time.

The current study suggests it was likely the latter. It found that these two groups likely lived side-by-side following farmers’ migration into Europe. Later, they would start slowly integrating local hunter-gatherers into their communities, a process that seems to have increased in speed and scope as time went on.

The authors from Harvard Medical School, the Hungarian Academy of Sciences, and the Max Planck Institute for the Science of Human History say that these early farming communities also exhibited various levels of hunter-gatherer ancestry. The current paper focused on this element, and the wider framework of interactions between early farmers and preexisting hunter-gatherer groups in three locations: the Iberian Peninsula (today’s Spain and Portugal), the Middle-Elbe-Saale region in north-central Europe, and the Carpathian Basin (largely overlapping today’s Hungary and western Romania).

The team drew on high-resolution genotyping techniques to analyze the genomes of 180 early farmers, 130 of whom are newly reported in this study. The individuals lived from around 6000 BC to 2200 BC.

“We find that the hunter-gatherer admixture varied locally but more importantly differed widely between the three main regions,” says Mark Lipson, a researcher in the Department of Genetics at Harvard Medical School and co-first author of the paper. “This means that local hunter-gatherers were slowly but steadily integrated into early farming communities.”

The share of hunter-gatherer genes in these communities’ genome never reached high levels, but it did increase over time. This suggests that hunter-gatherers weren’t pushed out by the encroaching farmers — rather, the two groups lived side-by-side, developing deeper ties and interacting more frequently over time.

Local interactions

Furthermore, the team reports that farmers in each location only mingled with hunter-gatherers from the same area. This suggests that once they remained largely sedentary after settling an area, thus limiting their interaction with farming or hunter-gatherer communities farther away.

This allowed the researchers to differentiate groups of early European farmers by their “specific local hunter-gatherer signature,” says co-first author Anna Szécsényi-Nagy of the Hungarian Academy of Sciences, adding that it’s the first time anyone has been able to do so. Farmers in Spain, she explains, “share hunter-gatherer ancestry with a pre-agricultural individual from La Braña, Spain.” Those in central Europe are more closely tied to groups such as hunter-gatherers from the Loschbour area, Luxembourg, and those in the Carpathian basin share ties with local groups in their area.

Using statistical models to track the origin of DNA blocks inherited by 90 individuals from the Carpathian Basin who lived in roughly the same period, the team also produced a rough estimate of how the populations mixed. The results indicate an ongoing process, starting off small and picking up in speed and intensity over time.

“We found that the most probable scenario is an initial, small-scale, admixture pulse between the two populations that was followed by continuous gene flow over many centuries,” says senior lead author David Reich, professor of Genetics at Harvard Medical School.

The team believes that thorough, detailed databases similar to the one used in their study could help reveal new information about how and when peoples in other areas of the world mixed and evolved.

The paper “Parallel palaeogenomic transects reveal complex genetic history of early European farmers” has been published in the journal Nature.

Reinventing rice: New saltwater rice developed in China could feed over 200 million people

The new salt-resistant species could boost China’s production by 20%, providing unexpectedly good yields.

There are also reported benfits to these strains. Image credits: Xinhua.

Rice can be grown pretty much anywhere in the world, even on steep hills and mountain areas. However, it’s labor-intensive and requires ample quantities of water, which has made it a staple in many parts of Asia, where labor is cheap and water is abundant. However, rice is also grown in many low-lying coastal areas, such as Bangladesh or Eastern China, where millions of hectares are threatened by soil salinity. If soil salinity grows too much, it affects the plant’s physiology, destroying entire crops. This is why having salt-resistant rice can be such a game changer.

At the Saline-Alkali Tolerant Rice Research and Development Center in Qingdao, eastern China, researchers and students planted over 200 types of rice. They then treated the soil with seawater from the Yellow Sea, and progressed just like with a regular rice paddy. The scientists were confident in their projects and expected yields of around 4.5 tons per hectare, but the results were even better: four types registered 6.5 to 9.3 tons per hectare, making the prospect of commercial availability much more likely. This is significantly higher than the global average yield, which is around 4.5 tons per hectare.

[Also Read: Simple way of cooking rice could halve its calories]

This approach is not new. In the 1970s, Chinese researchers started looking at ways to make rice more resistant to salt. After decades of trait selection, cross-breeding and genetic screening, they finally narrowed it down to eight species — but yields were still low, just around 2 tons per hectare. Now, they seem to have finally achieved the big breakthrough. Although costs are still a big problem, the fact that they are the biggest problem is a good sign.

Surprisingly high yields made saltwater rice much more attractive. Image credits: Xinhua.

A kilogram of the rice costs 50 yuan (US$7.50), about 8 times more than regular rice. However, cost is expected to go down as mass production increases, and rice itself is a pretty cheap food. Considering that in total, China has more than one million square kilometres of waste land — an area big enough to fit Texas and California — it’s easy to see why researchers are so thrilled. It offers the potential to feed a lot of people, even if it does mean paying a bit more.

There are also other benefits to this technique. Saltwater keeps pests and parasites at bay, meaning that producers might reduce costs even more. Also, while the rice itself is not salty, it is richer in nutrients such as calcium. Professor Huang Shiwen, the leader of the rice disease research team at the China National Rice Research Institute in Hangzhou, Zhejiang, said this could help keep many potentially harmful bacteria at bay.

“To survive in the harsh environment, these species must have some ‘diehard’ genes which may enable them to better resist the attack of certain diseases or bugs, especially those happening at the root or lower stalk,” he said.

Yuan Longping, who has long studied salt-resistant rice founded Yuan Ce Biological Technology, a Qingdao-based start-up which plans to bring this modified rice to the tables. He believes that already by the end of the year, the “sea rice” will make 10 million yuan ($1.5 million) in revenue, a very optimistic figure for something up to a few months ago was completely uncertain.

The new rice reportedly has a different texture and flavor. Image credits: Xinhua.

However, not everyone is a fan of this project. Liu Guangfei, a wasteland treatment expert at Beijing-based Eagle Green Technology Development, said that the rice would only grow in China’s coastal areas, whereas 90 per cent of the saline and alkaline soils in China are in inland areas. These soils are also rich in sodium sulphate, which the rice isn’t prepared to deal with. Furthermore, he adds, planting the new rice species would only enable soils to gather more and more salt, rendering then completely unusable for any other plants. Instead, Liu argues, other commercial plants such as jujube and wolfberry could be grown over these soils, helping reduce the salt quantity and improving overall soil quality.

“Planting this rice will keep the land salty forever,” he said. “It cannot be used to grow other crops.”

But again, the decisive argument will perhaps be the economic one. This is a spectacular achievement which could make a big difference in some parts of the world, but at the same time — China now has a surplus of rice. Whether or not it can fit the new addition to the market remains to be seen.