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New Research: Synthetic Nitrogen Destroys Soil Carbon, Undermines Soil Health

Author: Tom Philpott | February 24, 2010

“Fertilizer is good for the father and bad for the sons.”
–Dutch saying

For all of its ecological baggage, synthetic nitrogen does one good deed for the environment: it helps build carbon in soil. At least, that’s what scientists have assumed for decades.

If that were true, it would count as a major environmental benefit of synthetic N use. At a time of climate chaos and ever-growing global greenhouse gas emissions, anything that helps vast swaths of farmland sponge up carbon would be a stabilizing force. Moreover, carbon-rich soils store nutrients and have the potential to remain fertile over time–a boon for future generations.

The case for synthetic N as a climate stabilizer goes like this. Dousing farm fields with synthetic nitrogen makes plants grow bigger and faster. As plants grow, they pull carbon dioxide from the air. Some of the plant is harvested as crop, but the rest–the residue–stays in the field and ultimately becomes soil. In this way, some of the carbon gobbled up by those N-enhanced plants stays in the ground and out of the atmosphere.

Well, that logic has come under fierce challenge from a team of University of Illinois researchers led by professors Richard Mulvaney, Saeed Khan, and Tim Ellsworth. In two recent papers (see here and here) the trio argues that the net effect of synthetic nitrogen use is to reduce soil’s organic matter content. Why? Because, they posit, nitrogen fertilizer stimulates soil microbes, which feast on organic matter. Over time, the impact of this enhanced microbial appetite outweighs the benefits of more crop residues.

And their analysis gets more alarming. Synthetic nitrogen use, they argue, creates a kind of treadmill effect. As organic matter dissipates, soil’s ability to store organic nitrogen declines. A large amount of nitrogen then leaches away, fouling ground water in the form of nitrates, and entering the atmosphere as nitrous oxide (N2O), a greenhouse gas with some 300 times the heat-trapping power of carbon dioxide. In turn, with its ability to store organic nitrogen compromised, only one thing can help heavily fertilized farmland keep cranking out monster yields: more additions of synthetic N.

The loss of organic matter has other ill effects, the researchers say. Injured soil becomes prone to compaction, which makes it vulnerable to runoff and erosion and limits the growth of stabilizing plant roots. Worse yet, soil has a harder time holding water, making it ever more reliant on irrigation. As water becomes scarcer, this consequence of widespread synthetic N use will become more and more challenging.

In short, “the soil is bleeding,” Mulvaney told me in an interview.

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Get Your Dirt Working With Microbes

Fighting the carbon battle one compost bin at a time

Author: Cody Hooks | Published: November 9, 2017

My first composting experiment started in college with a cute, ceramic bin on the kitchen counter of the drafty house I shared with seven other people. We were being green and trying to find ways to actually keep the smell of eight people (hippies, no less) in check.

My second composting operation was here in Taos — the most sensible way to use up the food scraps and help out the plants I’d grow the following season.

But what if compost could address issues other than wounds suffered by the ego for not having a greener thumb? What if compost could actually be part of the constellation of solutions to humanity’s biggest challenge – climate change?

It can.

Rivers and Birds, an environmental education nonprofit based in Arroyo Seco, recently hosted a workshop by the New Mexico State University scientist and compost innovator, David C. Johnson.

Together with his wife, Hui-Chan Su Johnson, the pair created the Johnson-Su Composting Bioreactor.

Making compost that helps regenerate the natural processes in dirt doesn’t take a specific recipe. As Johnson explained, he created a stationary composting bin, or bioreactor, that costs about $40 in materials and can turn leaves, manure or food scraps into a compost dense with a diversity of microbes and fungi.

And Johnson’s research, undertaken in the dry, hot environment of southern New Mexico, has shown that soil treated with his compost can be more productive than even the rainforests of the Amazon.

“If we are to achieve long-term stability in our agricultural systems,” Johnson wrote in a bioreactor manual, “it may be advantageous for us to start emulating the composting actives of nature and our ancestors.”

Mighty microbes

Let’s start with the amazing fact that there are microbes (tiny, invisible fungi, bacteria and single-cell organisms) are everywhere and life is utterly dependent on them.

The human body is a perfect example of this microbial dependence in action. Cell to cell, every human is outnumbered by the microbes that live in and on the body. Our shared space isn’t neutral; fecal transplants (of gut microbes) and eating fermented foods (rich in beneficial bacteria) are among the ways of restoring a healthy microbiome.

And in the same way microbes are essential to the body, they’re essential to the soil.

But agriculture disturbs the soil. Tilling quite literally turns well-established microbial communities upside down. And in the process, stores of carbon are released.

“Plowing actually damages the soil structure and exposes soil carbon — the crumbling blackness that generations of farmers have recognized as a feature of the best, richest soil — to the air, where it combines with oxygen and floats away as carbon dioxide,” Kristin Ohlson wrote in her 2014 book, “The Soil Will Save Us.”

And carbon dioxide is a big contributor to climate change, according to scientists.

Sequestering carbon – trapping the gas back in the ground – is a big step in mitigating climate change as best we can. But getting carbon back into the ground is going to take working with the soil as a whole ecosystem and not as an isolated input in agricultural production.

“We’ve bred plants to grow in poor soils,” Johnson explained. “Let’s flip that. Let’s fix our soils and see what plants can do.”

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Biochar Market: Agriculture Sector and Waste Management Leading Application Segments

Author: Hiren Samani | Published: October 11, 2017

Biomass, the carbon-rich product produced from the pyrolytic treatment of biomass or greenwaste, can be used to improve the environment and agriculture in a number of ways. The high level of persistence of the substance in soil combined with its nutrient-retention properties make it an ideal solution for soil amendment and a way of improving crop yields. Moreover, the substance is used as an ideal way of carbon sequestration, providing significant implications for the mitigation of environmental degradation owing to the rising levels of CO2 in the atmosphere.

In a recent report, Transparency Market Research estimates that the global biochar market will chart an impressive CAGR of 14.5% from 2017 to 2025, incrementing to an opportunity of US$14,751.8 thousand by 2025 from its estimated valuation of US$444.2 thousand in 2016.

In this blog post, TMR analysts answer questions related to some of the most crucial aspects of the Global Biochar Market:

Which feedstock is most prominently used for the production of biochar?

A variety of feedstock is used for the production of biochar, including animal manure, woody biomass, agricultural waste, and produces such as sugarcane, coconut, rice, bamboo, and cereals. Of these, the segment of woody biomass accounted for nearly 50% of the overall market in 2016. The high quality of biochar produced from woody biomass finds vast usage in the field of soil amendment. The improvement of quality of soil achieved with the use of biochar is highly valued in areas such as agriculture, forestry, and gardening. In the near future as well, woody biomass will continue to remain the most used feedstock for the production of biochar, accounting for a significant share of the global biochar market in the near future.

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Climate Change Is Making It Harder to Grow Rice

Malaysian farmers are watching changing weather patterns threaten their staple crops, and switching to other crops might be the only answer.

Author: Sawsan Morrar | Published: October 11, 2017

When Abdulhamid bin Saad, 68, reminisced over the 50 years he’s worked the rice paddies, he had no problem remembering what farming was like before using the new technologies available today. But Saad could not explain why the weather feels warmer these days, or why rainfall seems to occur less frequently. “I’m just a farmer,” he told me.

Saad might not fully grasp why the changes are occurring, but the new generation of farmers in Malaysia are already experiencing what rising temperatures does to their paddy fields. Shafrizal bin Abdulhamid, Saad’s son, said that while this year’s rain came surprisingly early, the stresses over climate change are mounting, threatening their crop and their livelihoods.

These shifts in weather patterns are spurring what once had seemed unimaginable: A reconsideration of rice as the central food in Malaysia’s diet. While domestic consumption is about 2.8 million tons this year, the average local rice yield was 30 to 50 percent lower than its potential, according to Malaysian research. Local researchers are now looking towards more climate-adaptive foods, imagining a way to move forward with climate change in mind.

And it’s poised to become worse. The world is expected to warm by an additional three degrees Celsius by 2050. While a warmer climate may affect rain and irrigation, other changes are not as apparent. As temperature rises and carbon dioxide levels are elevated, the nutritional content in crops begins to decrease due to the changes. This means less food, and less profit for farmers.

Saad’s paddy fields are conveniently located next to the largest irrigation channel in Malaysia, Wan Mat Saman, allowing him access to fresh water. Many farmers in the area, though, are not so fortunate. According to the International Rice Research Institute (IRRI), approximately 35 percent of Malaysian rice is solely grown with rainwater, leaving farmers even more vulnerable to changing weather patterns.

“It’s difficult to prepare for harvest when you cannot rely on rainwater, and you don’t know its schedule,” Abdulhamid said.

Abdulhamid’s family eats rice three times a day. When I visited in March, they gathered at lunch to enjoy a meal of chicken legs, yams, and white rice under a sheltered patio that overlooks acres of their paddy field. Beyond their field are other paddy fields as far as the eye can see. The patchwork of crops stretches to Alor Setar, the capital of Kedah, only minutes away by motorcycle, a common form of transportation in the state.

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Climate Change: Could Sustainable Agriculture Be the Silver Bullet We Are Looking For?

Agriculture has become one of the greatest threats to the future of our planet, writes Magdy Martínez-Solimán from UNDP.

Author: Magdy Martinez-Soliman | Published: October 5, 2017

As world leaders convened at the UN’s annual General Assembly last week, amidst the backdrop of New York’s Climate Week, the message was clear: we must act now and we must act together to tackle climate change.

It’s inspiring rhetoric but what exactly does this mean in practice?

When we, the global community, are confronted with mounting and seemingly overwhelming challenges in the face of climate change, it’s often difficult to know what to tackle first.

Where should we focus our efforts? Protecting the forests, the lungs of our Earth? What about the increasing scarcity of fresh water, waning food security, air pollution, reducing poverty, disaster preparedness in the face of more ferocious storms? The list goes on.

However, there is a more holistic way to tackle these issues and it starts with agriculture.

Many of these challenges can be considered symptoms of a broader, and frankly unsustainable, global agriculture economy which, until recently, we have been reluctant to collectively confront.

Agriculture in the 21st century is fundamental; it’s essential to our very existence. Today, the commercial production of agricultural commodities is a dominant economic force in many national and developing rural economies. Worldwide, the livelihoods of 2.5 billion people depend on agriculture.

Yet, ironically, agriculture has also become one of the greatest threats to the future of our planet. Considered to be the biggest driver of tropical deforestation today, the consequences of unsustainable agriculture include losses to habitats and biodiversity, rising carbon dioxide levels as well as the degradation of essential ecosystem services such as clean water and fresh air which we depend on for our very survival.

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Can American Soil Be Brought Back to Life?

A new idea: If we revive the tiny creatures that make dirt healthy, we can bring back the great American topsoil. But farming culture — and government — aren’t making it easy.

Author: Jenny Hopkinson | Published: September 13, 2017

Four generations of Jonathan Cobb’s family tended the same farm in Rogers, Texas, growing row upon row of corn and cotton on 3,000 acres. But by 2011, Cobb wasn’t feeling nostalgic. Farming was becoming rote and joyless; the main change from one year to the next was intensively planting more and more acres of corn and soy, churning up the soil and using ever more chemical fertilizers and herbicides to try and turn a profit.

“I’d already had the difficult conversation with my dad that he would be the last generation on the farm,” Cobb said.

While looking for a new job, Cobb stopped into a local office of the U.S. Department of Agriculture to pick up some paperwork. That day, the staff was doing a training session on soil health. He stayed to watch and was struck by a demonstration showing a side-by-side comparison of healthy and unhealthy soils.

A clump of soil from a heavily tilled and cropped field was dropped into a wire mesh basket at the top of a glass cylinder filled with water. At the same time, a clump of soil from a pasture that grew a variety of plants and grasses and hadn’t been disturbed for years was dropped into another wire mesh basket in an identical glass cylinder. The tilled soil–similar to the dry, brown soil on Cobb’s farm—dissolved in water like dust. The soil from the pasture stayed together in a clump, keeping its structure and soaking up the water like a sponge. Cobb realized he wasn’t just seeing an agricultural scientist show off a chunk of soil: He was seeing a potential new philosophy of farming.

“By the end of that day I knew that I was supposed to stay on the farm and be part of that paradigm shift,” Cobb said. “It was that quick.”

The shift he’s talking about is a new trend in agriculture, one with implications from farm productivity to the environment to human health. For generations, soil has been treated almost as a backdrop — not much more than a medium for holding plants while fertilizer and herbicides help them grow. The result, over the years, has been poorer and drier topsoil that doesn’t hold on to nutrients or water. The impact of this degradation isn’t just on farmers, but extends to Americans’ health. Dust blowing off degraded fields leads to respiratory illness in rural areas; thousands of people are exposed to drinking water with levels of pesticides at levels that the Environmental Protection Agency has deemed to be of concern. The drinking water of more than 210 million Americans is polluted with nitrate, a key fertilizer chemical that has been linked to developmental problems in children and poses cancer risks in adults. And thanks to some modern farming techniques, soil degradation is releasing carbon—which becomes carbon dioxide, a potent greenhouse gas—instead of holding on to it. In fact, the United Nations considers soil degradation one of the central threats to human health in the coming decades for those very reasons.

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Author Judith Schwartz Examines Water Management

Author: Tracy Frisch | Published: July 19, 2017

When writer Judith Schwartz learned that soil carbon is a buffer for climate change, her focus as a journalist took a major turn. She was covering the Slow Money National Gathering in 2010 when Gardener’s Supply founder Will Raap stated that over time more CO2 has gone into the atmosphere from the soil than has been released from burning fossil fuels. She says her first reaction was “Why don’t I know this?” Then she thought, “If this is true, can carbon be brought back to the soil?” In the quest that followed, she made the acquaintance of luminaries like Allan Savory, Christine Jones and Gabe Brown and traveled to several continents to see the new soil carbon paradigm in action. Schwartz has the gift of making difficult concepts accessible and appealing to lay readers, and that’s exactly what she does in Cows Save the Planet And Other Improbable Ways of Restoring Soil to Heal the Earth, which Elizabeth Kolbert called “a surprising, informative, and ultimately hopeful book.”

For her most recent project, Water in Plain Sight: Hope for a Thirsty World, Schwartz delves into the little-known role the water cycle plays in planetary health, which she illustrates with vivid, empowering stories from around the world. While we might not be able to change the rate of precipitation, as land managers we can directly affect the speed that water flows off our land and the amount of water that the soil is able to absorb. Trees and other vegetation are more than passive bystanders at the mercy of temperature extremes — they can also be powerful influences in regulating the climate.

The week after this interview was recorded, Schwartz travelled to Washington, D.C., to take part in a congressional briefing on soil health and climate change organized by Regeneration International. As a public speaker, educator, researcher and networker, she has become deeply engaged in the broad movement to build soil carbon and restore ecosystems.

ACRES U.S.A. Please explain the title of your book, Water in Plain Sight.

JUDITH D. SCHWARTZ. The title plays on the idea that there is water in plain sight if we know where to look. It calls attention to aspects of water that are right before us but we are not seeing. By this I mean how water behaves on a basic level, not anything esoteric.

ACRES U.S.A. How should we reframe the problems of water shortages, runoff and floods?

SCHWARTZ. Once we approach these problems in terms of how water moves across the landscape and through the atmosphere, our understanding shifts. For example, when we frame a lack of water as “drought,” our focus is on what water is or isn’t coming down from the sky. That leaves us helpless because there’s really not much we can do. But if we shift our frame from drought to aridification, then the challenge becomes keeping water in the landscape. That opens up opportunities.

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Here’s What Indonesia Is Doing About Haze From Forest and Peatland Fires

Author: Nithin Coca | Published: August 10, 2017

In 2015, massive fires burned across Indonesia, releasing hazardous smoke across neighboring countries. How close is the country to meeting its goal of reducing haze from future fires?

August 10, 2017 — Two years ago, Indonesia experienced the largest fire event in modern human history, with more than 2.5 million hectares (6 million acres) of tropical landscape burning, emitting more greenhouse gases than all of Germany does in a year. But the most visible sign of the disaster was the haze that spread across a huge swath of Asia; the particulates in the smoke sullying the air that tens of millions of people breathed. According to one study, the haze resulted in an estimated 100,000 deaths

It was a watershed moment — and one the world knew could not be repeated as global attention focused on the role forests play in regulating climate during that year’s COP-21 climate conference. Fires in the tropics are dangerous, emitting huge amounts of greenhouse gases and releasing toxins, especially when they sit atop carbon-dense peat bogs. But these disasters have become commonplace in Indonesia due to exploitation of peatlands. 

“The root cause of this crisis was forest clearance and peatland drainage at large scale by the plantation sector, which has turned previously valuable ecosystems into huge monoculture plantations, while leaving remaining forests and peatland at high risk of burning,” says Annisa Rahmawati, forests campaigner at Greenpeace Southeast Asia. For years, both palm oil and paper pulp industries built canals to drain peatlands across the country to expand production, which cause them to turn from wet landscapes to dry ones, ready to burn. 

“Fires were a symptom of failed policies,” says Arief Wijaya, senior manager for climate and forests at the World Resources Institute Indonesia. “How the government managed land use was not effective.” 

Historically, agencies at national and local levels distributed land to smallholders and large plantation companies under a patchwork system with no comprehensive national oversight. The result was overlapping and conflicting boundaries, making it impossible to determine who controls burned land. 

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The Most Neglected Threat to Public Health in China Is Toxic Soil

Published: June 8, 2017 

Tang Donghua, a wiry 47-year-old farmer wearing a Greenpeace T-shirt, smokes a cigarette and gesticulates towards his paddy fields in the hills of southern Hunan province. The leaves of his rice plants poke about a foot above water. Mr Tang says he expects to harvest about one tonne of rice from his plot of a third of a hectare (0.8 acres) near the small village of Shiqiao. There is just one problem: the crop will be poisoned.

Egrets and damselflies chomp lazily on fish and insects in the humid valley below the paddy fields. But just beyond this rural scene lurks something discordant. Mr Tang points to a chimney around 2km away that belches forth white smoke. It belongs to the smelting plant which he blames for bringing pollution into the valley. Cadmium is released during the smelting of ores of iron, lead and copper. It is a heavy metal. If ingested, the liver and kidneys cannot get rid of it from the body, so it accumulates, causing joint and bone disease and, sometimes, cancer.

Hunan province is the country’s largest producer of rice—and of cadmium. The local environmental-protection agency took samples of Mr Tang’s rice this year and found it contained 50% more cadmium than allowed under Chinese law (whose limits are close to international norms). Yet there are no limits on planting rice in polluted areas in the region, so Mr Tang and his neighbours sell their tainted rice to the local milling company which distributes it throughout southern China. Mr Tang has sued the smelter for polluting his land—a brave act in China, where courts regularly rule in favour of well-connected businesses. His is an extreme case of soil contamination, one of the largest and most neglected problems in the country.

Soil contamination occurs in most countries with a lot of farmland, heavy industry and mining. In Ukraine, for example, which has all three, about 8% of the land is contaminated. A chemical dump in upstate New York called Love Canal resulted in the poisoning of many residents and the creation of the “superfund”, a federal programme to clean up contaminated soil. But the biggest problems occur in China, the world’s largest producer of food and of heavy industrial commodities such as steel and cement.

China’s smog is notorious. Its concentrations of pollutants—ten or more times the World Health Organisation’s maximum safe level—have put clean air high on the political agenda and led the government to curtail the production and use of coal. Water pollution does not spark as much popular outrage but commands the attention of elites. Wen Jiabao, a former prime minister, once said that water problems threaten “the very survival of the Chinese nation”. China has a vast scheme to divert water from its damp southern provinces to the arid north.

Dishing the dirt

Soil pollution, in contrast, is buried: a poisoned field can look as green and fertile as a healthy one. It is also intractable. With enough effort, it is possible to reduce air or water pollution, though it may take years or decades. By contrast, toxins remain in the soil for centuries, and are hugely expensive to eradicate. It took 21 years and the removal of 1,200 cubic metres of soil to clean up the Love Canal, a site covering just 6.5 hectares.

China’s soil contamination is so great that it cannot adopt such a course (see map). The country is unusual in that it not only has many brownfield sites (contaminated areas near cities that were once used for industry) but large amounts of polluted farmland, too. In 2014 the government published a national soil survey which showed that 16.1% of all soil and 19.4% of farmland was contaminated by organic and inorganic chemical pollutants and by metals such as lead, cadmium and arsenic. That amounts to roughly 250,000 square kilometres of contaminated soil, equivalent to the arable farmland of Mexico. Cadmium and arsenic were found in 40% of the affected land. Officials say that 35,000 square kilometres of farmland is so polluted that no agriculture should be allowed on it at all.

Stick in the mud

This survey is controversial. Carried out in 2005-13, it was at first classified as a state secret, leading environmentalists to fear that the contamination might be even worse than the government let on. Not everyone, however, is as pessimistic. Chen Tongbin, head of the Institute of Geographic Sciences and Natural Resources Research in Beijing, thinks the figure of 19.4% is too high. Based on local studies, he says 10% is nearer the mark. Even that would be a worrying figure, given that China is trying to feed a fifth of the world’s population on a tenth of the world’s arable land. The conclusion seems to be that China’s soil pollution is widespread and that information about it is disturbingly unreliable.

There are three reasons why the contamination is so extensive. First, China’s chemical and fertiliser industries were poorly regulated for decades and the soil still stores the waste that was dumped on it for so many years. In 2015, for example, 10,000 tonnes of toxic waste was discovered under a pig farm in Jiangsu province in the east of China after a businessman proposed plans to build a warehouse on the plot and tested the soil. In 2004 construction workers on the Beijing metro suddenly fell ill when they started tunnelling under a site previously occupied by a pesticide factory.

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Prince Charles Urges Diversity in the Crop World

Author: Umberto Bacchi  | Date Published: June 7, 2017 

Britain’s Prince Charles called on Wednesday for greater diversity in crop planting to feed a growing population in the face of global warming.

Access to a large pool of genetic information held by different plant varieties is key for scientists, who are racing to find crops capable of tolerating increasingly high temperatures, water shortages and dry conditions.

Three quarters of the world’s plant genetic diversity has been lost since the 1900s, as farmers shift from local varieties to genetically uniform, high-yielding crop breeds, according to the U.N. Food and Agriculture Organization (FAO).

Speaking in a video message in support of an international lobby group, Food Forever, Charles said the trend to grow fewer varieties was “profoundly alarming”.

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