Tuesday, 13 December 2011

We need a new ‘Brown Revolution’

The Worldwatch blog, ‘Nourishing the Planet’, reports that Howard Buffet has called for an African ‘brown revolution’ which focusses on improving soil conditions. The philanthropist and farmer, president of the Howard G. Buffett Foundation, has called on the international community to rethink its approach to agricultural development in Africa. Although he acknowledges that a variety of solutions are needed to make Africa food secure, he argues that aid agencies must devote their attention to soil conditions across the continent.

He expects his ideas to meet resistance among those hoping to replicate in sub-Saharan Africa the phenomenon of the “Green Revolution,” which introduced improved seed varieties, pesticides, and fertilizer to farmers in Southeast Asia. While the Green Revolution is credited with dramatically boosting yields in the late 20th century, opponents claim that its high-tech solutions destroyed local environments and made farmers dependent on expensive inputs.

“A Green Revolution really won’t work for the majority of Africa farmers,” says Buffett – a keynote speaker at the recent World Food Prize symposium in Des Moines, Iowa, USA. “We need a Brown Revolution. We need to change the debate about how to help African farmers.” His foundation released a new report on food insecurity in Africa, which can be accessed here.

Thursday, 17 November 2011

Trees 'boost African crop yields and food security'

A recent BBC online article refers to a study reported in the International Journal of Agricultural Sustainability which shows that planting trees which improve soil quality can help boost crop yields for African farmers. In addition, fertiliser tree systems (FTS) also help boost food security and play a role in "climate proofing" the region's arable land.

The BBC quotes researchers from the World Agroforestry Centre who say poor soil fertility is one of the main obstacles to improving food production in Africa. "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.

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 fertiliser tree systems (FTS).

In some regions it is possible to rest land and leave it to lie fallow between crops. In others, where population density and food demand is higher, other means to boosts soil fertility are necessary which don’t limit crop production, such as intercropping annual crops with leguminous trees.

Read more here.

Friday, 11 November 2011

US researchers studying using perennial grasses for biofuels and biochar

Farmers in the United States will be urged to grow perennial grasses for biofuel production, as a result of a $25 million research grant aimed at developing transportation and aviation biofuels made from tall grasses, crop residues and forest resources.

According to Wallaces Farmer, a multi-state, interdisciplinary team led by Ken Moore, Iowa State University professor of agronomy, recently won a $25 million USDA grant and will develop the blueprint for using marginal farmlands to grow perennial grasses that will, in turn, provide a biomass source for a drop-in biofuel.

The article states that growing perennial grasses on marginal Midwest cropland has many environmental advantages, including reducing soil and nutrient runoff, slowing soil erosion and increasing carbon sequestration. Growing those grasses currently has few benefits for the farmers who own the land and make the production decisions, however. And convincing farmers to take land out of corn production when prices hover near $6 to $7 per bushel will require developing a market for the perennial grass that gives farmers a solid return. The researchers claim that using marginal land for this kind of biofuel production takes the "food-versus-fuel" argument out of the equation.

"In general, the lands we are using in our research aren't really very good for producing food, so we are taking the food-versus-fuel argument out of the equation," says Moore. "By using perennial grasses on this land, we are reducing soil erosion, improving soil and water quality and even providing wildlife habitat."

The comprehensive study will also involve researchers from many disciplines in order to look at the big picture. For instance, some will be studying pyrolysis, which is a process that uses thermal decomposition of biomass in the absence of oxygen to produce an energy-rich liquid known as bio-oil. Additional refining turns the bio-oil into gasoline and petrochemicals.

A co-product of the pyrolysis process is a carbon- and nutrient-rich solid called biochar that can be used to as a soil amendment to increase the productivity of poor soils. The researchers say that preliminary research suggests that biochar can improve corn production in marginal soils, and can even double yields in poor soil.

A twitter account has been set up to follow the research at @cenusabioenergy.

Read the full article here.

Friday, 4 November 2011

Arsenic-eating bacteria may boost food production

Physorg.com reports that arsenic-resisting bacteria could greatly improve cleanups of toxic environments and potentially boost agricultural production, according to a new University of Florida study. The bacteria were found in arsenic-contaminated soil surrounding the Chinese brake fern, a plant known for its ability to remove arsenic, a deadly, carcinogenic poison, from the environment.

After the scientists isolated bacteria from the soil, they added it to the fern’s growing environment in the laboratory where it broke arsenic down into a more available form readily absorbed by the fern. In addition to the increase in arsenic absorption, they also noted a gain in the uptake of the nutrient phosphorus by the fern, which led to better growth.

The researchers said that said more studies are needed to explore whether the bacteria can be widely used in agriculture.

Read the full article here.

Monday, 31 October 2011

Water: inefficient use not shortage the problem in food production

New Agriculturalist – funded by the UK’s Department for International Development – reports that the world's major river systems have enough water to double food production by 2050 if it’s used efficiently and distributed fairly.  The quoted CGIAR study finds that inefficient use and inequitable distribution of water are the problem, not water scarcity. With a 50 per cent increase in water productivity in rain-fed agriculture, the authors argue that the world can be easily fed if farmers have access to the proper inputs, technology and markets.

Water scarcity is not affecting our ability to grow enough food today," says Alain Vidal, director of the Challenge Program on Water and Food (CPWF). "Yes, there is scarcity in certain areas, but our findings show that the problem overall is a failure to make efficient and fair use of the water available in these river basins. This is ultimately a political challenge, not a resource concern." He adds, "Huge volumes of rainwater are lost or never used, particularly in the rain-fed regions of sub-Saharan Africa. With modest improvements, we can generate two to three times more food than we are producing today.”

Tuesday, 18 October 2011

Sunflowers no help for decontamination efforts

I reported in an earlier blog post that growing sunflowers on Fukushima’s radioactive soil may help to decontaminate it. Well, unfortunately, this has not happened.

The Japanese Daily Yomiuri reports that in spite of their reputation for absorbing radioactive caesium, they have had little effect on cleaning up the soil around the damaged nuclear plant.

The experiment on removing caesium started in May in farmland totalling 7,000 square metres in Iitatemura and other locations in Fukushima Prefecture. Following the outbreak of the nuclear crisis, a large amount of radioactive substances were released, contaminating the areas around the plant. Four soil decontamination treatments were trialled, the least effective of which was the use of plants. The most effective was scraping away the topsoil, but this is very expensive and leaves a large amount of radioactive soil which needs to be properly disposed of.

Read more here.

Monday, 10 October 2011

Organics – it is, or is perhaps not, the answer

Two interesting articles I’ve come across in the past couple of weeks which explore the seemingly age-old question of which is better – organic or non-organic food and production. This seems to be one of those debates which will go on forever, and while the mudslinging (in the UK at least) seems to have abated in recent years, it seems a shame that the two production systems are so often presented as ‘either/or’, diametrically opposing and incapable of existing alongside one another.

Me? I think that both systems have a lot to offer and that more should be done to foster links and share knowledge between them. They can both play a part in meeting the challenges of the 21st century.  I do believe that organic agriculture has a lot to offer in terms of its proponents' and practicioners' better understanding of soil managament and health, in general, than the conventional sector.  Conventional agriculture also has substantial potential, not least it's enthusiasm for embracing new technology, including GM (where caution is definitely needed), which may be viewed with suspicion by organic enthusiasts.

According to this report which quotes Dr Steve Savage from the University of California, organic agriculture will neither save, nor feed, the planet.  In a nutshell, his reasons for this are that the sector is too small, production costs make organic food too expensive and, in general, organic production systems just aren't as productive as conventional ones.

Conversely, however, this article reports on America's longest running side-by-side comparison of organic and conventional farming practices has come out with some results which appear to contradict the views above.   Originally created to study the transition from conventional to organic production, this 30-year study also examined productivity, soil quality, energy and economics.   Key findings show that organic yields match or surpass conventional yields and outperform them in drought years.   Organic farming systems build rather than deplete soil organic matter, and use 45% less energy than conventional production.   In addition, the report finds that organic farming systems are also more profitable.

Wednesday, 28 September 2011

Increasing water use efficiency in potato production

Planting potatoes in flat, rather than ridged beds can increase irrigation water use efficiency in some production systems, according to U.S. Department of Agriculture (USDA) researchers.

Historically, US potato growers seeded their crops in ridged rows (as British growers tend to do) and watered their plants by channelling surface irrigation to flow through the furrows between the rows. Even though most commercial potato producers in the Pacific Northwest now irrigate their crops with sprinklers, they still typically use ridged-row planting systems.

But this planting configuration allows irrigation runoff to collect in the furrow and percolate below the crop root zone. This means that the water is unavailable to the crops, and can also lead to increased nitrate leaching from the soil.

The researchers found that using a flat bed system increased yields by an average of 6 percent, even though 5 percent less water was used for irrigation. This meant that using flat beds instead of ridged rows for potato production led to an overall 12 percent increase in irrigation water use efficiency. The gains were attributed to several factors, especially the probability that planting potatoes in flat beds improves water and nitrogen use efficiency because more water reaches the potato roots.

Read the report in full here.

Wednesday, 21 September 2011

Increased tropical forest growth could release carbon from the soil

Research by the UK Centre for Ecology & Hydrology and the University of Cambridge shows that as climate change enhances tree growth in tropical forests, the resulting increase in litterfall could stimulate soil micro-organisms leading to a release of stored soil carbon.

The study, published in the scientific journal Nature Climate Change, looked at rainforest at the Smithsonian Tropical Research Institute in Panama, Central America, to study how increases in litterfall - dead plant material such as leaves, bark and twigs which fall to the ground - might affect carbon storage in the soil.

Results show that extra litterfall triggers an effect called 'priming' where fresh carbon from plant litter provides much-needed energy to micro-organisms, which then stimulates the decomposition of carbon stored in the soil.

Read more here.

Monday, 19 September 2011

Radical overhaul of farming could be 'game-changer' for global food security

New practices could enhance rather than degrade the world's ecosystems, double agricultural production and protect natural systems.

According to the authors of new research released recently at the World Water Week in Stockholm, a radical transformation in the way farming and natural systems interact could simultaneously boost food production and protect the environment — two goals that often have been at odds.  The authors warn, however, that the world must act quickly if the goal is to save the Earth's main breadbasket areas — where resources are so depleted the situation threatens to decimate global supplies of fresh water and cripple agricultural systems worldwide.

A new analysis resulting from the joined forces of the International Water Management Institute (IWMI) and the United Nations Environment Programme (UNEP) outlines the urgent need to rethink current strategies for intensifying agriculture, given that food production already accounts for 70 to 90 percent of withdrawals from available water resources in some areas.   The report, An Ecosystem Services Approach to Water and Food Security, finds that in many breadbaskets, including the plains of northern China, India's Punjab and the Western United States, water limits are close to being "reached or breached."  Meanwhile, 1.6 billion people already live under conditions of water scarcity, and the report warns that number could soon grow to 2 billion.   The current situation in the Horn of Africa is a timely reminder of just how vulnerable to famine some regions are.

Read more here.

Tuesday, 13 September 2011

Crops with deeper roots capture more carbon, fight drought

Creating crops with deeper roots could soak up much more carbon dioxide from the air, help mankind fight global warming and lead to more drought-tolerant varieties, a British scientist says in a study. Douglas Kell of the University of Manchester says crops can play a crucial role in tackling climate change by absorbing more of mankind's rising greenhouse gas emissions from burning fossil fuels.

Doubling root depth to two metres would also make crops more drought resistant, improve soil structure and moisture, store more nutrients and reduce erosion, Kell says in the study published online in the Annals of Botany journal. Plants use carbon dioxide (CO2) and sunlight to grow and carbon is stored in the roots and leaves. Deeper and more bushy roots would store more carbon underground.

Many crop varieties have root systems that don't extend beyond one metre, limiting their access to water during drought but ensuring rapid growth above ground and bumper yields when the weather is good.

"Doubling root biomass to a nominal two metres is really the key issue, together with the longevity of the carbon they secrete and sequester below-ground," Kell says in the study.

He said previous studies have doubted the benefits of deep roots locking away large amounts of carbon. But this was because the studies did not take soil measurements much below a metre.

"What matters is not so much what is happening now as what might be achieved with suitable breeding of plants with deep and reasonably long-lived roots. Many such plants exist, but have not been bred for agriculture," he says.

Read more from Reuters here.

Tuesday, 6 September 2011

USDA Scientists Study Effects of Rising Carbon Dioxide on Rangelands

Rising carbon dioxide (CO2) levels can reverse the drying effects of predicted higher temperatures on semi-arid rangelands, according to a study published in the scientific journal Nature by a team of U.S. Department of Agriculture (USDA) and university scientists.

Warmer temperatures increase water loss to the atmosphere, leading to drier soils. In contrast, higher CO2 levels cause leaf stomatal pores to partly close, lessening the amount of water vapour that escapes and the amount of water plants draw from soil. This new study finds that CO2 does more to counterbalance warming-induced water loss than previously expected. In fact, simulations of levels of warming and CO2 predicted for later this century demonstrated no net change in soil water, and actually increased levels of plant growth for warm-season grasses.

"By combining higher temperatures with elevated CO2 levels in an experiment on actual rangeland, these researchers are developing the scientific knowledge base to help prepare managers of the world's rangelands for what is likely to happen as climate changes in the future," said Edward B. Knipling, administrator of the Agricultural Research Service (ARS), USDA's principal intramural scientific research agency.

Read more from the USDA here.

Friday, 2 September 2011

Intercropping perennials with maize brings substantial benefits

Growing perennial cover crops under annual maize crops can bring substantial benefits to the soil and environment without compromising maize yields, according to Iowa State University research. The study shows that soil and water quality, and possibly even farm profits could all stand to benefit from this technique.

The researchers used standard agronomic practices to manage a cover crop of perennial Kentucky bluegrass – the most suitable crop found – between rows of maize which was established annually using strip tillage. The system they used kept soil, carbon and nutrients in the fields, rather than it being lost to erosion, runoff and the atmosphere, and still allowed 200 bushels of corn to be yielded per acre (12.6 tonnes/hectare). This compares very favourably with these 10-year average yields for the state of IOWA.

One of the drivers for the research was the potential future demand for stover – corn residues – for use in producing biofuels. Currently this usually remains on the ground after the crop is harvested and helps reduce soil erosion and replenishes nutrients and organic matter. But the prospect of this being removed led many to fear that soil erosion and nutrient loss would increase as biofuel technologies developed.

Read the full report here.

Wednesday, 31 August 2011

Beetles: an alternative to herbicides?

British and French researchers have found that ground beetles can reduce the number of weed seeds surviving in the soil, thus contributing to weed management and reducing the need for herbicides. The findings provide further support for calls to conserve farmland biodiversity.

The study, funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the French Institut National de la Recherche Agronomique (INRA), found that grass weeds were reduced more than other weeds, which is important because many UK farms have severe grass weed problems. Some of the species which were targeted by ground beetles are increasingly resistant to herbicides and can have significant effects on crop yields owing to competition for resources.

As herbicides become increasingly restricted, alternative means of weed control have the potential for significant impact. The report suggests that with the right management, ground beetles could replace some herbicide applications and significantly reduce weed populations. It goes on to say that agri-environment schemes such as Environmental Stewardship can already help to create suitable habitats for such invertebrates.

Read the full report here.

Friday, 26 August 2011

Roundup damages soil?

A recent Reuters report claims that heavy use of the glyphosate-based herbicide Roundup can cause damaging changes to soils as well as compromising yields of GM crops which US farmers are cultivating. Repeated use of glyphosate damages plant root structure and research indicates that the chemical could also cause fungal root disease, according to the United States Department of Agriculture (USDA).

According to the Reuters report, Roundup is the world's best-selling herbicide and its use has increased as Monsanto, the world's biggest seed company, continues to roll out herbicide-tolerant "Roundup Ready" crops. Roundup Ready corn, soybeans and other crops are beloved by farmers because farmers can spray the herbicide directly onto their crops to kill surrounding weeds, and Roundup Ready corn and soybeans varieties make up the vast majority of those crops grown in the United States.

In addition, website Motherjones.com quotes Iowa-based agronomy consultant Dr Michael McNeill, who claims that "farmers' increased use of Roundup is actually harming their crops because it is killing micronutrients in the soil that they need, a development that has been documented in several scientific papers by the nation's leading experts in the field. For example, harmful fungi and parasites like fusarium, phytopthora and pythium are on the rise as a result of the poison, while beneficial fungi and other organisms that help plants reduce minerals to a usable state are on the decline. The overuse of glyphosate means that oxidizing agents are on the rise, creating oxides that plants can't use, leading to lower yields and higher susceptibility to disease."

Monsanto has said in the past that glyphosate binds tightly to most types of soil, is not harmful and does not harm the crops. The company has said that its research shows glyphosate is safe for humans and the environment.

Wednesday, 24 August 2011

Livestock key to less desertification

A report in Australian magazine Farm Weekly suggests that using livestock is the only management tool available to combat climate change-induced desertification.

The ‘unpopular and controversial’ idea arises from observations made by Allan Savory, president of the Africa Centre for Holistic Management, of southern Africa, where it was noticed that the African savannah could support extremely large herds of herbivores year after year without degradation.

In contrast to this, land that was destocked to accepted optimum conditions and allowed to return to wilderness was increasingly subject to desertification. Mr Savory argues that subjecting grassland to occasional heavy grazing, which mimicked ‘natural’ conditions, actually improved vegetation growth. 

Read the full report here.

Wednesday, 17 August 2011

Pesticides lost to the atmosphere exceed losses through runoff

American researchers have revealed that pesticide losses to the atmosphere, through volatilisation, increase when soil moisture levels are high. A long-term U.S. Department of Agriculture (USDA) study found that herbicide volatilisation regularly exceeded herbicide losses arising through field runoff.

Scientists from the USDA Agricultural Research Service studied the field dynamics of atrazine and metolachlor, two herbicides commonly used in maize production. Both herbicides are known to contaminate surface and ground water, which was primarily thought to occur through surface runoff.

The team found that when air temperatures increased, so too did soil moisture’s role in influencing atmospheric losses – volatilisation – of these two chemicals, something that had not been considered or observed in earlier experiments. When soils were dry and air temperatures increased, there was no increase in herbicide volatilization, but herbicide volatilization increased significantly when temperatures rose and soils were wet.

According to the report, most surprising was that throughout the study, herbicide volatilization losses were significantly larger than surface runoff. When averaged over the two herbicides, loss by volatilization was about 25 times larger than losses from surface runoff. Read more here.

Thursday, 11 August 2011

Wildfires spur emissions of greenhouse gases from soil

The Summit County Voice reports that an accidental bush fire during a climate change experiment revealed that wildfires can significantly increase the release of the environmentally-damaging gas nitrous oxide, which can, in turn, accelerate climate change.

“Soils are the major source of nitrous oxide in the atmosphere,” said Jamie Brown, graduate student in biological sciences at Northern Arizona University (NAU) and co-author of the study. “So increased soil emissions of nitrous oxide will accelerate global warming.”

Brown worked with other researchers from NAU, Stanford University, the University of Paris and the University of Lyon. Their experiments were based on an experimental grassland which was exposed to simulated and simultaneous environmental changes relating to heat, extra carbon dioxide in the atmosphere, more rain, more nitrogen deposition, and, when part of the experiment accidentally burned, wildfire.

“Alone, the treatments had little influence on nitrous oxide emissions, but what was really surprising was the interaction with wildfire, causing a huge burst of nitrous oxide production,” said NAU professor Bruce Hungate, Brown’s thesis adviser and co-author on the study.

“Increasing wildfire frequency and the changing climate could cause these soil micro-organisms to release more nitrous oxide into the atmosphere, accelerating global warming,” Brown said. Read the full report here.

Tuesday, 9 August 2011

Sunflowers may heal Fukushima’s radioactive soil

According to this report, activists in Japan are looking to sunflowers to help decontaminate soil affected by the Fukushima nuclear disaster. A group of civil servants and young entrepreneurs are asking people to grow sunflowers, then harvest and send the seeds to north-eastern Japan to grow in, and hopefully clean, the contaminated soils near to the damaged power station.

Japanese scientists have already conducted a test by growing sunflowers in the contaminated soil on farmland near the nuclear plant. Sunflowers have already been shown to germinate and sprout in this soil and if it is confirmed that the growing plants have absorbed significant quantities of radioactive caesium, scientists will use bacteria to decompose the plants into what will be classified as radioactive waste.

The report explains how the sunflowers can help: “The process of extracting contaminants from the soil via plants is called phytoremediation. While animals can move away from pollutants or other toxics (if they’re lucky), plants have evolved ways to live with the toxics and eventually extract them from the soil. The downside is that the concentrated pollutants, such as radioactivity or lead, can then pass along the food chain if not disposed of properly. Sunflowers were used to suck up radioactive caesium and strontium in a pond at the Chernobyl nuclear accident site in 1994 and to remove uranium from contaminated springs near the Oak Ridge (TN) National Laboratory in 1996.”

Friday, 5 August 2011

Growing plants with friendly fungi

As the UK bathed in a rain-free spring this year and global rainfall patterns are forecast to shift and alter, being able to maintain and increase food production with intermittent rainfall will become increasingly important. Researchers at the University of Exeter are looking at ways of tackling this problem by studying whether adding a safe and harmless fungus to compost boosts the growth and proliferation of crops' roots which can help them grow using less water.

The research, highlighted on the Biotechnology and Biological Sciences Research Council (BBSRC) website, also includes trials involving a supplier to a major supermarket brand which are investigating whether the plants exposed to the fungus can be grown in the absence of fertiliser too.

Dr Chris Thornton, one of the researchers, has been studying the growth promotion effect of the fungi in glasshouse-grown lettuce. "In the absence of fertiliser you still get an amazing growth increase with a five-fold improvement in root matter," says Thornton. "This is the first time we know of that it's been tried on brassica [broccoli and sprouts] plants in the field."

In addition, previous studies have shown that the fungus has properties as a natural biocontrol agent of pathogenic fungi and could reduce the need for synthetic fungicides. For more on the research, click here.

Wednesday, 3 August 2011

Soils and climate change

Two recent articles, one from Australia and one from the US, refer to sometimes contrasting attitudes in the debate about how best to manage soils effectively in the face of a changing climate.

In Cellulosic Fantasy: Ending Corn Ethanol Subsidies, writer Steve Breyman argues against the development of new technologies which will convert plant ‘waste’ into biofuels; specifically, cellulosic ethanol.   Apparently it’s currently harder, more expensive, and unprofitable to produce ethanol from cellulose (woody biomass) as compared to corn kernels but the US Department of Energy is reported to be supporting (with a $105 million loan guarantee) the expansion of an ethanol refinery in Iowa.

The New York Times states that commercial production of ethanol from waste products like husks is the ‘holy grail’ of the ethanol industry.   Professor Breyman, however, argues (quite rightly in my opinion) against this sort of technology on the basis that this so-called waste is of vital importance to the soil and contributes to maintaining and increasing soil organic matter (SOM) levels which help to reduce erosion and improve drainage and moisture retention.  Read more of what he has to say here.

The Australian government seems to be taking a different approach to its US counterpart, however, over how soils can help society deal with climate change.   To complement the carbon farming initiative  (which will allow farmers to earn credits for planting trees, reducing pollution from fertiliser and methane emissions from livestock), farmers stand to gain from $429 million-worth of funding into the best ways to store carbon in the soil and drive down pollution in the agriculture sector.

According to a report in The Australian newspaper, an additional $201m has been secured from the federal government to engage scientists and independent experts to develop ways to improve soil carbon storage and reduce emissions from livestock and crops.   Read the full story here.