terra pret / soil
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an 6 24
The "most-deprived" areas across the planet are in facing a land crisis, BBC reports, according to the World Food Programme.
Due to droughts and flooding, the organization's global office director Martin Frick told BBC, that because "the land can no longer sustain crops" in some places, there are "zero" harvests left as a result.
Furthermore, Frick warns that "that without efforts to reverse land degradation globally, richer countries would also begin to suffer crop failures" as well.
READ MORE: Don't say 'climate': Ron DeSantis signs bill removing references from state law
Frick noted that "as a father of three, he was 'not a fan of doomsday scenarios', but admitted that 'what we are seeing is most worrying,'" BBC reports.
The World Food Program director, however, offered a glimpse of hope by arguing that it's still possible for countries to move "toward localised farming that seeks to reinvigorate the land."
Still, BBC reports, "Meanwhile, flash floods in Afghanistan earlier this year are estimated to have destroyed 24,000 hectares of land already considered highly degraded. Environmentalists expect that as soil degrades, failing crops will strain global food supplies and increase migration from affected areas."
READ MORE:Is wastewater an answer for adapting to climate change?
Frick emphasized, "There's too much carbon in the air and too little carbon in the soils. With every inch of soil that you're growing, you're removing enormous amounts of carbon out of the atmosphere. So healthy soils – carbon-rich soils – are a prerequisite to fixing climate change."
Save Soil chief science officer Praveen Sridhar told the news outlet, "It's going to be disaster for human beings. It’s going to be like Mad Max."
Shrihar added, "There will be no humanity. There will be no charity. There will be no fairness... The only thing that lets you be will be survival."
*BBC's full report is available at this link.
http://www.allpowerlabs.com/news/a-perspective-on-terra-preta-and-biochar.html
[bkgd lit rev]
Is Terra Preta Charcoal Amended Soil?
The idea that terra preta is anthropogenic charcoal amended soil is not without controversy. Proponents of the hypothesis that terra preta is anthropogenic charcoal amended soil support this hypothesis on account of several findings: analytical methods examining the microstructure of the carbon in terra preta confirm that it is pyrogenic, and terra preta was often found to have pottery shards incorporated into it (whether incidentally or by design). Inferring from the thousands of hectares of land mass cultivated as terra preta, along with the depth of the terra preta and how thoroughly the charcoal is incorporated into the soil, the idea that terra preta formed by gradual incorporation of char from repeated massive forest fires seems implausible, especially given that it is found in the Amazon rainforest.
The strongest argument against terra preta being anthropogenic comes from the observation that terra preta regenerates. The late William Woods, one of the pioneering biochar researchers who contributed to the biochar renaissance, observed that in Brazil, terra preta has been mined and sold as fertile topsoil and potting mix for decades. The miners dig away the top 20cm of terra preta off the top of the mining area, and move on to another area, leaving the mined area to recover for 20 years. Over the course of time, the terra preta thickens as it regenerates itself from the forest litter that falls on it. By this account, it would appear that terra preta is merely a special form of forest litter compost. This also suggests that much of the observed depth of terra preta may not be originally cultivated material, but later growth due to the conversion of forest litter.
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The regeneration of terra preta from forest litter suggests that the microbiome of terra preta may have as much of an influence as added charcoal, imparting the character of the underlying material on organic material that decays upon it, analogous to the propagation of a sourdough starter “mother dough” into freshly added flour. However, it is important to point out that the charcoal content of terra preta cannot regenerate and cannot simply reproduce; pyrogenic carbon requires high temperatures to form its associated microstructures, and does not form in the decaying organic matter that builds up on terra preta. Furthermore, from the few videos and photos where terra preta mining can be observed, it appears that the material is not black like known examples of charcoal amended terra preta, but rather brown, suggesting that though this material is identified with terra preta, it probably does not contain charcoal, unless soil fauna have mixed deeper layers of soil with the new material (a process known as
If this is so, what is going on? What is the relationship and relative contribution of charcoal and the microbiome of terra preta? And what does this mean for our theories of the origins of terra preta and our attempts to optimally use charcoal as a soil amendment?
It turns out that terra preta is not the only soil that regenerates. The regeneration of terra preta appears to be an example of negative priming.
Negative Priming
Priming describes the phenomenon of the reduction of humus from soil and a multiplication of microbial biomass upon the decay of organic residues added to the soil, such as forest litter falling upon the ground in the autumn. As the microbial decomposers begin to consume the organic residue and multiply, there is a loss of humus and an increase in microbial biomass (called the priming effect), suggesting that the decomposition of fresh residues results in further decomposition of existing humus. As the decomposition finishes, the microbial biomass gradually reduces as the level of soil humus increases, resulting in a net increase in the amount of humus. This effect is observed in forest soils, and is termed negative priming....
...The regeneration of terra preta appears to be negative priming at work. The microbiome and charcoal are both involved, because the addition of charcoal appears to modify the microbiome of compost and soil. For example, the addition of biochar to compost (not the mixing of biochar with finished compost, but the addition of biochar at the beginning of the composting process) has been found to significantly abate the methane emissions of compost by favoring methanotrophs (methane eating bacteria) over methanogens (methane producing bacteria). Terra preta has even been found to foster mycorrhiza and host higher populations of free-living diazotrophs (nitrogen-fixing bacteria which are not bound to the root nodules of legumes). [SeeGeotherapy: Innovative methods of soil fertility restoration, carbon sequestration, and reversing CO2 increase, ch. 10,Geology into Biology, by David Yarrow. p. 208 and p. 219.] These are merely a couple of examples; compost and soil are home to tens of thousands of species of microbes, and biochar likely also exerts selection pressures on these microbes that result in significantly different proportions of various species, resulting in a significantly different microbiome from the surrounding soil. It would be this altered microbiome that colonizes and decomposes the new forest residue landing upon it, transforming it into regenerated terra preta populated with the same microbiome, exhibiting all of the characteristics to the parent material due to the microbiome, while lacking charcoal.
In our own field work with biochar at Gill Tract Community Farm in Albany, California, we have observed that biochar significantly alters the behavior of compost piles, resulting in compost with noticeably different characteristics. In 2018, Gill Tract Community Farm partnered with the Local Carbon Network as an early adopter of our biochar. Wary of the break-in period of suppressed plant growth incurred by adding biochar directly to soil, we decided to send the biochar through their compost piles as an exploratory application. Prior to adding biochar to their compost piles, the piles would heat up to about 130˚F, but the heat would dissipate when the piles were turned, and would not recover. After adding biochar to the compost pile, the compost would heat up to 155˚F, and would remain that hot for nearly a month. By the end of six weeks of composting, the piles would often be at temperatures over 130˚F.
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https://insideclimatenews.org/news/27092016/looking-earth-itself-climate-solution-soil-obama-vilsack-carbon-emissions
As President Obama scrambles to seal his climate legacy before he leaves office, his administration is taking a serious look downward—at soil.
The administration is intent on developing its plan to meet the emissions reductions goals it agreed to in last year's Paris climate accord, and that plan will likely outline how farmland, with its huge potential to sequester carbon, will play a key role.
"Attention to soil health is gaining momentum out of frustration with our inability to regulate greenhouse gas emissions at an economy-wide scale," said Thomas Driscoll, director of conservation policy and education for the National Farmers Union, the country's second-largest farm industry group. "People are starting to pay attention to farming and land-use because they're having so much trouble everywhere else."
The world's cropland has the potential to store 20 billion tons of carbon on about 4 billion acres over a 25-year period. That is enough to offset as much as 15 percent of carbon emissions from fossil fuel burning each year. France recently launched an international initiative to boost the organic carbon in soil by 4 parts per thousand, which it says is enough to offset annual increases in overall carbon emissions.
"I wish the U.S. were taking the lead. We're the world's breadbasket," saidRattan Lal, a soil science professor at Ohio State University and the incoming president of the International Union of Soil Sciences. "But the French are, and as long at the U.S. follows along, then at least we're heading in the right direction."
Soil scientists like Lal and conservation groups have long recognized farmland's ability to capture and store carbon, but the U.S. agricultural industry has been slow to embrace it. The American Farm Bureau, the biggest farm industry group in the country, has questioned the reality of manmade climate change, which makes it highly unlikely to push its members to take steps, particularly costly ones, to address carbon.
When soil is tilled or forests are cleared, natural carbon in the soil is released into the atmosphere, where it mixes with oxygen to form heat-trapping carbon dioxide. Since agriculture began about 10,000 years ago, soils have lost as much as 70 percent of their natural carbon. The simple solution is to stop clearing forests for cropland and reforest the ones that have been cleared, but increasingly, the focus has shifted to cropland's potential to capture and store carbon. With a growing global population and the need to feed an estimated 9.7 billion people by 2050, every acre of arable land will become essential.
By using techniques like "no-till," in which farmers plant crops without disturbing the soil, they can minimize the release of carbon. Farmers can also plant cover crops after the growing season that improve soil health by adding carbon, make the soil less prone to erosion and draw in and store carbon from the atmosphere.
More U.S. farmers may be asked to do their part and use these techniques soon.
The White House's Council on Environmental Quality recently held a series of meetings, including one with agriculture and forestry stakeholders, to investigate industry trends and these and other possible mitigation strategies. The White House Office of Science and Technology Policy in August announced a new interagency working group on soil health. And last year, Agriculture Secretary Tom Vilsack launched "Building Blocks for Climate Smart Agriculture," a framework for helpingfarmers deal with —and mitigate — climate change, including using carbon sequestration.
Through the Building Blocks initiative, the Agriculture Department aims to increase carbon stored in forest and soils by 120 million metric tons of carbon dioxide equivalent per year by 2025, a goal the agency has said will help the U.S. meet its mid-century targets.
Agriculture worldwide accounts for a quarter of all greenhouse gas emissions, but unlike industries such as transportation and energy, it has largely escaped discussion as a climate target.
"I think we're the only sector of the economy that has the potential to reduce existing emissions," said Driscoll. "What's exciting is that agriculture has the ability to reduce emissions — by buying an energy efficient grain drier or bolting solar panels on your barn for hot water or by applying fertilizer in ways that avoid nitrous oxide from going into the atmosphere. But we also have the ability to take carbon out of the atmosphere."
For the first time in more than 20 years of UN climate change talks, soil was on the agenda of at the Paris climate summit last year. The French government launched its initiative, dubbed "4 per Thousand," which encourages governments and NGOs to implement carbon sequestering and capturing practices.
The initiative, however, is based on voluntary commitments, an arrangement that critics say makes it merely symbolic. But it does signal that the government acknowledges the critical role that agricultural lands, and the farmers who make their living off them, play in stemming climate change.
"There's recognition that soils are a very large part of the carbon cycle, and when you look at options and potential around taking carbon out of the atmosphere and putting it somewhere else, soils are one of your greatest unexplored opportunities," said Harold M. van Es, a professor of soil science at Cornell University.
Over the past decade or so, more American farmers have started to employ the practices that store carbon or minimize its release.
"Soil health and soil carbon, which have been front and center for sustainable agriculture, including organic, for decades and decades, has suddenly become this big conversation in conventional agriculture, particularly around no-till and cover cropping," said Ferd Hoefner, policy director for the National Sustainable Agriculture Coalition. "It's one of the most hopeful things in agriculture.... It would be terrible if the U.S. submission for the mid-century [targets] in any way downplayed ag."
The numbers, however, are still relatively tiny. Only 2 percentof the farmland in the Mississippi River basin, for example, is planted with cover crops and about 35 percent of the cropland used to grow the eight major crops use no-till.
But environmental groups and academics are optimistic that more producers will start using these methods, not least because they improve soil health — and productivity.
Some Big Ag interests have started taking steps, largely because their industries depend on soil health. Monsanto, the world's largest seed company, announced last year that it would make its operations carbon-neutral by 2021 and the National Corn Growers Association linked up with conservation groups in 2014 to launch the Soil Health Partnership.
"I think they may be more swayed if they can be convinced of the benefits. It's their land," van Es said. "I think there are also indirect ways to encourage farmers. One is to provide carbon credits, or to reflect the increase in carbon in the soil in terms of land value."
Lal thinks the only way to get farmers to implement carbon sequestering practices is to pay them directly, a very hard sell to governments.
"I don't think farmers are going to do anything unless they're paid," he said. "So my suggestion was that every farmer that does conservation agriculture, should be given 16 dollars per acre.
"There's 4 bilion acres of cropland worldwide, so 16 times 4. It's a crude estimate. But that's the price of a few fighter jets, so do it."
PUBLISHED UNDER:
http://ecowatch.com/2016/05/21/carbon-farming-reverse-climate-change/
Are there agricultural practices that might offer more potential than the ones commonly discussed in the “carbon farming” conversation? In a companion post, I wrote about what the science tells us about cover cropping and reduced tillage, two practices getting a lot of attention in what I’ve called the “carbon farming” rage. Here I want to address some more agroecological practices, those that incorporate ecological principles and what is known from field research about their ability to add carbon to the soil.
:{ :(style="box-sizing:border-box;margin:0px;padding:0px;z-index:100;display:block;max-width:750px;max-height:563px"):}:Cattle graze here on a ranch in the Sand Hill region of North Central Nebraska. Grasslands cover a large percentage of the planet and research demonstrates greater potential with improved management (such as compost additions and plant composition) to increase soil carbon.
What Do We Know About Soil Carbon Potential Beyond the Basic Conservation Practices?
There is less research on the relationship of agroecological practices,such as crop rotations, agroforestry and improved grazing-based systems, with soil carbon—but what is known is very positive. A synthesis paper of global field studies found that crops in rotation plus cover crops increased total soil carbon by 8.5 percent. Some estimates have suggested that when land is shifted from use for growing agricultural crops to pasture for livestock, carbon increases significantly (by 19 percent, according to one study synthesizing several research sites). The same analysis found that returning some cropland to forest could lead to even larger soil carbon gains (up to 53 percent).
On grazing lands, which cover around 25 percent of lands globally, changes to management (for example, compost additions or improved grazing practices such as fertilizer additions or the use of native plant communities) can increase soil carbon such that small changes make a big difference when scaled up. Further, on the option of integrating of trees into agricultural lands, scientists have estimated the potential of agroforestry systems to increase soil carbon to be approximately 95 times greater than the conservation practices of no-till, cover crops and crop rotations (as estimated by one analysis that looked at many studies in the tropics).
This is quite impressive untapped potential, particularly when considering that many of these ecological practices receive a fraction of public research dollars. Of course, some of these practices require taking a small amount of land out of production, but if done strategically on low yielding unprofitable sections of a field, such diversification practices could offer a “win-win” in the form of cost savings for producers and environmental benefit for all.
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