A recent article by Célia Sapart, Postdoctoral Researcher, Atmospheric Physics and Chemistry Group at Utrecht University about how long human society has been having an affect on global atmospheric climate suggests that it may be far longer than anyone had previously thought.
“When snow falls on polar ice sheets, in Greenland and Antarctica for example, ai r is trapped between the snowflakes. Year after year, the snow compacts under its own weight to become ice, and air is enclosed in small bubbles. These are the best atmospheric archives on Earth.
By analysing the air enclosed in polar ice, we can reconstruct past changes in the atmosphere’s composition. We have reconstructed past methane (CH4) variations back to the Roman Empire period, and discovered that humans emitted significant amounts of methane 2,000 years ago.
Nobel Prize winner in chemistry Paul Crutzen described the current geological period as the “Anthropocene”, or the human era. It started with the onset of the industrial revolution in the second half of the 19th century, when human-related emissions of atmospheric trace gases strongly increased.
But did it really start then? For how long have humans influenced the composition of the atmosphere?
A decade ago, famous climatologist William Ruddiman suggested humans influenced the climate much earlier than previously thought. Ruddiman’s hypothesis was criticised, but a few years later isotope measurements on methane trapped in polar ice cores indicated strong biomass burning – likely related to human activity – had increased atmospheric methane levels before the 16th century.
The strength of isotope measurements is that they allow distinguishing variations in methane emitted from various sources. Indeed, every type of sources produces methane with a characteristic isotopic signature.
Because methane is emitted by multiple sources, understanding its budget is not straightforward. These sources can be divided into three categories: biogenic, pyrogenic and fossil sources, with each category comprising both natural and anthropogenic methane emissions.
Biogenic methane is formed by tropical and boreal wetlands, ruminants, rice paddies, landfills and waste water treatment. Pyrogenic emissions include biomass burning and the combustion of bio fuel. And fossil sources can be divided into two groups: fossil fuel and geological sources (methane formed deep in the Earth’s crust, which then travels upward through the sediment to the atmosphere).
In order to better understand the contribution of the different methane sources to the atmospheric burden, we have analysed the methane isotopic signature on ice core samples from Greenland. These samples date back to the Roman empire period.
Our results were interpreted with the help of atmospheric models. They show that the centennial-scale variations in isotope ratios can be attributed to changes in pyrogenic and biogenic sources. They also reveal several distinct periods of higher methane emissions from biomass burning within the last two thousand years.
Variations in biomass burning coincided partly with climate variability (changes in temperature and precipitation), but also with changes in human population and land use. For example, the burning-related emissions decreased during the decline of the Roman empire and the Han dynasty, and increased during the population expansion of the Medieval period. This is attributed to increased deforestation during those periods, but also to the burning of wood for heating purposes and metallurgy.
The construction of armour in medieval periods also affected the Earth’s atmosphere. DavidInc/Flick
Heavy metals in dust were recorded in the sediment of several lakes in Asia and in Greenland ice. This shows metallurgy, especially to produce weapons and tools, was important during these periods.
Further analysis of changes in land use was carried out by EPFL’s Atmosphere Regolith Vegetation group in Lausanne, Switzerland. Their results, together with the methane data, suggest that the long-term increase in methane concentration over the last two thousand years is caused at least partly by agricultural activities. For example, the development of rice paddies and irrigation of agricultural fields, thereby providing experimental evidence for the Ruddiman hypothesis.
It seems humans had a global impact on the atmosphere long before industrialisation. The results of our study show a need to reconsider the benchmark of natural versus “anthropogenic” eras, while aiming to predict future climates.”
In a recent article by ABC reporters Eleanor Bell and Suzanne Smith titles “Future of food now a global battle” the issue of gene patenting was examined in the context of current research to uncover the genes responsible for stress and drought resistence (something that PolyGenomX has extensive knowledge of). Snippets of the report below, for the full article click here.
The race is on to find and patent all the known stress resistant and drought resistant plant genes in the world. The largest private and public seed, biotech and agrichemical companies and institutions have been granted at least 900 patents over plant genes that will be able to survive a world beset by climate change.
Scientists predict continents such as Africa will need crops that can survive at least a two degree rise in temperature, otherwise thousands of people could starve.
With predictions too that the world’s population will reach 9 billion by 2050, governments are also involved in building seed banks and working with big multinationals to find stress-resistant genes that can be scientifically altered to make plants more resilient.
According to Monsanto Australia’s Peter O’Keefe, Australia is in a unique position to benefit from and contribute to solving the global food shortage expected over the next few decades.
“We’re a big exporter on the world stage, so it’s important that we do our bit,” he said.
“But secondly, Australian farmers need to remain competitive, so we need to have access new technologies and particularly biotechnology to be able to increase production and remain competitive.”
But concerns about the rise in the number of patents being awarded to the top 10 multinational companies, who also have significant market share in seeds, chemicals and other essential farming stock, has prompted Liberal Senator Bill Heffernan to launch another inquiry into the issue of patents over genes.
The inquiry, to begin on June 30, will look at whether the patents granted already over plant genes give too much control to companies and institutions and how that control might affect farmers in the future.
A recent Senate inquiry into patents on human genes is expected to report in early June. A landmark court case in the US has also found patents were wrongly awarded over the breast cancer BRCA 1 and 2 genes; the company who owns the patents, Myriad Technologies, is appealing the decision. Currently Myriad Technologies charges women in the United States more than $3,000 for the breast cancer susceptibility test to see whether they carry the BRCA 1 and 2 genes. There is no second opinion tests allowed.
Senator Heffernan says, “In terms of national security and sovereignty, countries need to have control over their seed production not necessarily commercially controlled; now, if a company in America owns the absolute gene patent to a seed bank where does it leave countries like Africa (sic) and God knows where?”
But there is debate about whether the patents are actually granted over natural biological material. Supporters of the patents say the companies who have isolated the genes have done so by using an “invention” and therefore should be allowed control over the genes. Opponents believe the genes are natural biological material and no different when transferred to a lab environment and therefore should be judged as a “discovery” and not be allowed to be patented. The US District Court in the Myriad case found that the patents were null and void because the genetic material claimed in the patents was identical to that which exists inside the body.
Monsanto Australia – one of the top five multinational companies in the seed, biotech and agrichemicals business – says patents drive innovation. Executive director Peter O’Keefe says, “Without patents there’s no reward for commercial companies that spend a lot of time and effort on research and development, discovery and innovation. Patents are the key to ensuring that this research continues.”
He says Monsanto will be applying for more plant gene patents in the future and is happy to comply with Australian regulatory processes.
“We’re in the process of commercialising water-use efficient or drought tolerant corn in North America at the moment. It’s hypothetical but if we were able to bring that product to Australia then we would go through the regulatory process.”
Monsanto rejects Senator Heffernan’s belief that there is no inventive stage in the current plant gene patents.
“There’s a misconception that genes can be patented, that genetic material in its native state can be patented, and that’s incorrect. There has to be a lot more involved in the patent application than just picking a piece of genetic material and slapping a patent on it … it is about combining those genes with other genetic material, reinserting it into another plant. So the plants are lot more complicated than what we call genes or what we refer to genes.”(PGX note – this is specific to GMO’s, our plant technology recreates a natural process called polyploidy in which the plant replicates its genetic material in response to stress, polygenomic plants created through our unique technology are NOT GMO!)
Monsanto says it broadly licenses its developments so the technology is widely used and not restricted. The company says it also waives licence fees and is not charging royalties on some crops in Africa as a philanthropic exercise.
Global markets and the patent system
Geoff Tansey, trustee of the UK Food Ethics Council and author of The Future Control of Food, says global markets and the OECD nations have developed a patent system that benefits the big players and not the small operators and farmers.
Under the World Trade Agreement, all countries must sign up to the Trade-related Aspects of Intellectual Property rights or ‘TRIPS’ convention. The convention forces each country to protect patent owners’ rights. Trade sanctions can be issued if signatories fail to honour patent holders’ intellectual property rights.
The impact on science
The CSIRO has patents on plant genes in crops, and benefits from revenue generated by its patents. One of its scientists, Dr TJ Higgins, is optimistic about the future of crop biodiversity.
“We have access to 300 different crops at least for food. Intellectual property rights are probably concentrated on five or six out of that group so I don’t see it as a major threat … but from the point of food security for the future I don’t see it as playing a major role. It’s much more important that we get stuck into research and development to feed the nine billion people.”
Dr Higgins says being fearful of patents is an old-fashioned view.
“When people say that patents are the worst thing to happen to Australian agriculture I think that’s a simple view of the world and probably not all that realistic. It would be nice to go back to the old ways, but the world has changed,” he said.
One patent expert, Dr Richard Jefferson, a molecular biologist and founder of a not-for-profit research organisation CAMBIA, says patents are encouraging the push to monetise research outcomes in the public sector. He says this could have severe implications for the type of science performed in Australia.
While Dr Jefferson believes Monsanto’s research is a critically important area of investigation, because of Australia’s arid environment he says the public sector should pursue different research initiatives.
“In our rush to find one effective tool, we may neglect many other alternatives that are very effective,” Dr Jefferson said.
He says complex research involving changing agricultural eco-systems through pest introduction or crop rotations aren’t receiving adequate funding. These methods, developed in paddocks and laboratories alike, often require interdisciplinary research and are difficult to commercialise.
We need a treaty to help people displaced by climate change
By David Hodgkinson, University of Western Australia
Climate change will lead to significant human displacement. The Intergovernmental Panel on Climate Change (IPCC) and other groups warn that the effects – including rising sea levels, heavier floods, more frequent and severe storms, drought and desertification – will cause large-scale population movements. How can we help these displaced people? I believe an international treaty could be the answer.
It’s important to take account of the different contexts and forms that climate change displacement may take. As Oli Brown of the International Organization for Migration has said, we need “international recognition of the problem, a better understanding of its dimensions and a willingness to tackle it”.
Existing law does not adequately provide for climate change displaced persons (CCDPs). There has been no coordinated response by governments to address human displacement due to climate change. And given the nature and magnitude of such displacement, ad-hoc measures may lead to inconsistency, confusion and conflict.
This can by addressed by collaboration among the international community. There seems to be a common interest in reaching a resolution, either by providing adaptation assistance or pre-emptive resettlement.
How a treaty could work
Parties to a treaty would be both developed and developing states. It would encompass those displaced internally and those who cross international borders. Most displacement will take place within a state.
The International Council on Human Rights Policy notes that “the most dramatic impacts of climate change are expected to occur in the world’s poorest countries”.
Assistance for those displaced internally would be shared by the home state and the international community. For those who have migrated across state borders, the treaty would outline the obligations of the CCDP and both the home and “host” states.
Significant numbers of people are likely to be displaced by climate change. Given that, en-masse designations of the status of climate change displaced persons through a process of request and determination by state parties and the treaty organisation is more workable and more appropriate than the individual satisfaction of definition-based criteria.
In the event of international displacement, the treaty would not compel state parties to the treaty to accept CCDPs. State parties may choose to enter bilateral displacement agreements between “home” and “host” states.
Keeping people at home
Any treaty would first contemplate providing pre-emptive assistance; then, if necessary, resettlement. It would prioritise those most at risk from the impacts of climate change. Providing assistance under the treaty could then be described as “anticipatory adaptation”.
Any treaty would largely operate prospectively, rather than reacting to a situation. Assistance to CCDPs would be based on a “bottom-up/top-down” assessment of their environment’s susceptibility to the effects of climate change. Ultimately, it would look at the likelihood of a place becoming uninhabitable.
The aim of the treaty, above all else, would be to enable people to stay in their homes as long as possible and, failing that, to move in a planned manner over time.
Determining whether people are displaced by climate change
A treaty would acknowledge problems in determining the impact of climate change on the displaced. It would also consider to which extent humans have contributed to a particular climate change event.
The treaty could adopt a “very likely” standard (greater than 90% probability) to identify “climate change events” as caused by human-induced climate change. Such a standard would provide increased certainty and targeted resource allocation, vital in the context of a treaty that could potentially apply to hundreds of millions of people.
Adopting a “very likely” standard means requests from state parties that might set the treaty in motion would overwhelmingly be about slow-onset, gradual displacement. This kind of displacement is more likely to be seen as a result of anthropogenic climate change than a sudden disaster.
Seeking progress where we can
It’s clear that there are obstacles to treaty-making. In terms of the UN Framework Convention on Climate Change (UNFCCC), the current negotiating process is unlikely to make significant progress. First the positions of major developed and developing states and their relationships with the climate must change. As has been noted, “since an agreement among the major emitters is unikely anytime soon, we should seek progress where we can, through whatever means and in any forums that are available”.
If the climate change problem is broken up and addressed in pieces, then it may be that any climate change displacement treaty could form one element of such a climate change governance approach, or part of any climate change “regime complex”.
A final point: in the Andes, if warming trends continue, many tropical glaciers may disappear within 20 years. This threatens the water supplies of over 70 million people. Bolivia’s ambassador to the United Nations, Pablo Solón, asks this question: “What do you do when your glacier disappears or your island is under water?”
One solution is a treaty for climate change displaced persons which sets out a framework for the collaborative provision of pre-emptive adaptation assistance – and, if necessary, relocation before glaciers melt and before islands are under water.
David Hodgkinson leads an international project team drafting a treaty for climate change displaced persons.
David Hodgkinson does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.
Interesting video on Youtube explaining a pilot scale torrefaction unit in Georgia;
March 27, 2012
Destroyed … Kalimantan peat swamp.
A $47 million Australian government project to restore Indonesian forests and peatland to protect large carbon stores has been quietly scaled back and is failing to meet even its modest revised goals, new research has found.
The findings follow an investigation by ANU academics Erik Olbrei and Stephen Howes into the progress of the Kalimantan Forests and Climate Partnerships project, launched in 2007 by the Howard government and since continued under Labor.
The project had originally aimed to re-flood 200,000 hectares of dried peatland, protect 70,000 hectares of peat forests, and plant 100 million trees in Central Kalimantan.
But in a new paper, the researchers say advice they received from AusAid officials in February suggests that now just over 10 per cent – or 25,000 hectares – of the original 200,000 hectares of peatland is expected to be re-flooded.
The authors also say to date only 50,000 trees have been replanted, well short of the 100 million target first touted.
There has also been little progress on removing large canals to drive the peatland re-flooding, due to delays around local environment permits.
Professor Howes and Mr Olbrei said delays in implementing many elements of the project would mean ”in our judgment, it is unlikely that the project, even in its scaled-back form, will be complete by July 2013”
The Kalimantan project is part of a $273 million government program to develop global action on reducing deforestation and developing a forest carbon offset market.
The researchers said the slow progress of such projects compared with the rapid rate of deforestation and peatland destruction in Indonesia, meant current approaches were not working. They recommended that if Australia decided to remain in the project it should be more ambitious, supported by high-level policy dialogue and larger public funds.
A spokesman for the Department of Climate Change said they were working with the Indonesian government to deliver on the objectives of the Kalimantan project in as short a time as possible, but did not have any plans to increase funding.
”As an innovative project, the Kalimantan Forests and Climate Partnerships is trialling new approaches.
”There have been challenges during the project so far; we are using those to learn and improve our approaches,” the spokesman said.
- Interesting follow up to this story is that PolyGenomX has previously developed a Eucalyptus robusta specifically for growing in the Peat Swamps of Borneo!
The ABC recently released a very indepth page on their website looking at all the issues arising from the contentious Coal Seam gas industry.
You can find it here;
PolyGenomX has a range of unique biological solutions for dealing with the salt and other contaminants that are released through the process of dewatering to capture the gas. For a brief overview click here.
On 28 October Air China conducted its first trial flight of a passenger jet powered by a mix of biofuel and traditional aviation fuel.
The Jet A-1 biofuel kerosene used in the flight was derived from the seeds of tung trees, more commonly known as japtropha.
Air China’s Boeing 747-400 landed safely at Beijing Capital International Airport at 9:30 a.m. after burning more than 10 tons of the biofuel, a 50-50 mixture of traditional Jet A-1 derived from oil and Jet A-1 processed from the japtropha seeds. The jatproha Jet A-1 is what’s known as a drop-in, simply being admixed in a 50-50 ratio with conventional Jet A-1, and requires no engine modifications.
Air China Vice President He Li said the composition and the burning efficiency of the biofuel admixture had been tested along with its impact on the Boeing 747′s four Pratt and Whitney JT9D high-bypass turbofan engines.
The Hydro-treated Renewable Jet Fuel (HRJ) used Honeywell/ Universal Oil Products’ process to produce the biofuel. According to Jennifer Holmgren , UOP’s former director for renewable energy and chemicals, UOP licenses the process “nonexclusively.” UOP said in a statement, “The flight is a result of a broader effort kicked-off in 2010 by China’s National Energy Administration and the U.S. Trade and Development Agency to address the technical, economic and institutional factors required for the development of a new biofuels industry in China.”
Air China is the People’s Republic of China flag carrier and one of the country’s major airlines, the world’s tenth largest airline company according to fleet size, operating nine Boeing 747s scheduled to be phased out. Air China has already retired five Boeing 747s.
According to the International Energy Agency, China will lead the world in “demand growth” for jet fuel through 2012, reaching 5.6 percent. Total worldwide demand for Jet A-1 is forecast to reach 239.4 million gallons per day during the same period, compared 214.2 million gallons in 2007, a demand-growth rate of 2.3 percent. A 2007 422-page National Petroleum Council study, Facing the Hard Truths About Energy, reports that global demand for energy, including jet fuel – will grow by as much as 60 percent by 2030. It is China’s growing civilian air capacity that makes the test significant, as China Civil Aviation Administration official Zhang Hongying said following the test that the jatropha-derived biofuel was now ready to be used for commercial flights.
The Air China test flight is the world’s sixth such demonstration flight using Jet A-1 derived from jatropha.
The success was long in coming. PetroChina vice president Shen Diancheng remarked that it had taken PetroChina a decade to overcome the technical barriers of converting jatropha oil into Jet A-1 aircraft, but now that tests have proven its viability, PetroChina expects to ramp up production to 60,000 tons of jatropha Jet A-1 annually by 2014.
China’s interest in developing biofuels for industrial use is growing rapidly. In late 2009 Boeing and China signed a biofuel agreement with the Chinese Academy of Sciences and Chinese universities calling for research and development that potentially could support commercialization of jatropha. China has been proactive in the biofuel area for a number of years, with jatropha planted in 2007, and the plant – either wild or cultivated – can be found in Sichuan, Yunnan and Guizhou provinces as well as the Guangxi Zhuang autonomous region. Yunnan currently has 33,000 hectares under cultivation and the Xinhua news agency reports that the country will have 13 million hectares of biofuel plantations by 2020 that will produce 6 million tons of biodiesel annually.
But commercial jatropha production has its bottlenecks. While jatropha grows wild in tropical regions and can be cultivated on land not suitable for crops, it produces a lot more on cropland, suggesting that if it becomes popular, airlines will have to be careful that it is not squeezing out crop production. Initial field tests of jatropha cultivation suggest that high oil yields require that the plant receive water, nutrients, and soil conditions that are comparable to many food crops.
A substantial drawback to jatropha is that it is currently harvested manually and commercial producers have found that the plant is more labor intensive than originally thought, especially for harvesting.
Despite these setbacks, commercial jatropha production is underway or being established abroad. Abundant Biofuels Corporation, which is headquartered in California, has jatropha cultivation projects underway in the Philippines, Columbia, Peru, and the Dominican Republic. D1 Oils plc of London, United Kingdom, has announced large projects in India, Malawi, and Zambia. A number of companies are reported to have recently acquired rights to cultivate jatropha in Ghana. The central and some state governments of India are promoting jatropha production on tens of millions of acres, although these efforts have been criticized for potential adverse impacts on forested areas, biodiversity, and food production. Early yields in India have been below expectations.
Accordingly, commercial firms growing jatproha and airlines worldwide will be watching events in China with great interest. Fuel and oil comprise 25 percent of airlines’ operating costs and when the price of jet fuel rises one cent, it increases the global cost of aviation $195 million.
Given the fiscal resources available in China, it therefore seems most likely that jatropha commercial aviation biofuel production will arise their first, if sufficient land not impacting the nation’s food production can be found.
Perhaps in the future the East will not be so red as green.
By. John C.K. Daly of http://oilprice.com
The Universtiy of Tenesse’s Institute of Agriculture released a paper titled “Are fast grown trees of low quality?” with some interesting revelations. PolyGenomX Partner Allan Abbott had this to say,
“After an in-depth discussion of what defines quality in wood, the conclusion is that “Healthy trees grow more quickly, but this does not necessarily imply a reduction in wood quality. For a given species, larger and older trees are usually the most valuable for wood products.” Larger trees are better, and that’s what we produce . . . nice to see it confirmed!”
A recent article in the BBC news sparked interest among PolyGenomX HQ, reporter Mark Kinver had this to say;
How Trees Boost Crop Yields & Food Security
The nitrogen-fixing roots of certain trees provide valuable nutrients to resource-poor arable land
Planting trees that improve soil quality can help boost crop yields for African farmers, an assessment shows.
Fertiliser tree systems (FTS) also help boost food security and play a role in “climate proofing” the region’s arable land, the paper adds. Researchers from the World Agroforestry Centre say poor soil fertility is one of the main obstacles to improving food production in Africa. The results appear in the International Journal of Agricultural Sustainability.
“In Africa, it is generally agreed that poor soil management – along with poor water management – is most greatly affecting yields,” explained co-author Frank Place, head of the centre’s Impact Assessment team.
He said that despite chemical fertilisers having been on the market for more than half a century, farmers appeared reluctant or unable to buy them. “Therefore, there have been a lot of attempts to bring in other types of nutrients from other systems – such as livestock and plants” he told BBC News.
“We have been working quite a lot on what is broadly referred to as ‘fertiliser tree systems’.”
Although it has been known for centuries that certain plants, such as legumes, “fix” nitrogen in the soil and boost food crop yields, Dr Place said that the centre’s researchers had been looking to develop a more active management approach such as FTS.
“Some farms, for example in Zambia, where the farms are larger, it is possible to rest arable land and allow it to lie fallow,” he observed. “But in places such as much of Malawi, where population densities are higher, they cannot afford to fallow their land; so we came up with alternative management systems where they could intercrop the trees with the (maize).”
While the technique is not new, Dr Place said that some of the nitrogen-fixing species used by farmers were probably not the most effective.
For example, farmers in East Africa had been using Cajanus cajan (also known as pigeon pea).
“A lot of the nitrogen was being stored in the trees’ seeds; so there was an effort to use other trees that put a greater volume in the soil, such as Gliricidia sepium (one of its common name is mother of cocoa),” he said.
“A really nice thing about G. sepium is that we have been coppicing some of those trees for 20 years and they still continue to grow back vigorously.”
What is ‘nitrogen-fixing’?
The atmosphere consists of about 80% nitrogen, but plants cannot use it in this form certain plants, such as legumes, have bacteria growing in their root hairs that convert it into a form that plants can use this form of nitrogen is know as “green manure” and is a nutrient that helps plants, such as food crops, to grow (Source: World Agroforestry Centre). However, he acknowledged that there were a number of challenges that had to be addressed in order to maximise yields.
For example, some systems suggested planting rows of trees between rows of crops with mixed results.
“We realised that there were a few management problems with that sort of system – what tended to happen was that there was too much competition between the crops and the trees,” Dr Place explained.
“We developed a new management system where the trees were cut very low to the ground at the time you are planting the crop so then there was no light competition.
“The trees go into a dormant state when you cut them like this, so the root system is not competing straight away for the nutrients, so the maize is free to become established. “The trees only really start to come out out of the dormant phase when the maize is already tall.” Another challenge was to provide enough seeds in order to have mass-scale planting. He said that balancing the provision of high-quality seeds with large local engagement was another hurdle that had to be overcome.
But the rewards in improved yields were noticeable, he added. “Some of the studies have shown that in TFS across Africa as a whole, yields are doubling or more in two-thirds of cases.”
Where the systems were not delivering such good results, Dr Place said that scientists were looking to refine current practices and modify them to suit the local conditions.
As well as helping to boost yields, the use of trees in agriculture has other benefits – such as helping to “climate proof” agriculture land.
One example, Dr Place said, was the use of Faidherbia albida (common names include winter thorn and apple-ring acacia) in West African arable landscapes. “It has a deep penetrating tap root, and it can secure a good water supply even in dry years,” he explained. “Generally speaking, tree roots do go much deeper than crop roots, so it is recycling nutrients and water from deeper reaches. There are also studies showing that these roots act as conduits and bring up water to surface root systems (such as those belonging to crops).”
The editor-in-chief of the International Journal of Agricultural Sustainability, Professor Jules Pretty from Essex University in , said the study illustrated that there was a growing movement of agricultural innovations across Africa that were increasing yields and at the same time improving the environment.
“Trees and shrubs in agricultural systems seem to break some of the rules of agriculture – in this case, farmers are using shrubs to create a diverse rotation pattern rather than year-on-year maize,” he told BBC News.
“The trees fix nitrogen and improve the soil; the leaves can be fed to livestock; the crops then benefit greatly in subsequent years.”
Article by Mark Kinver, Environment reporter, BBC News