Enriching poor fields with a new cost-effective subsurface water retention technology

Farmers install SWRT membranes in Marange area of Zimbabwe as part of the technology’s first trial in Africa in September 2019. CREDIT N. Chirinda / CIAT

Smallholder poverty in sub-Saharan Africa is often linked to sandy soils, which hold little water and are low in nutrients. A new technology may be able to enrich fields and farmers without massive investments in irrigation and fertilizer,

Many farmers across sub-Saharan Africa try to coax crops out of sandy soils that are not ideal for holding water and nutrients. Their harvests are predictably poor. A traditional approach would have them apply more fertilizers and use irrigation, but both of these options require access to resources and infrastructure that many of them do not have. A relatively new technology modeled for eight African countries, and currently being tested in Zimbabwe, shows potential for substantially improving harvests through increased water retention and accumulation of organic material to make soils more fertile.

The technology consists of long strips of polyethylene membranes installed in a U-shape below and near the root zones of crops. Known as subsurface water retention technology (SWRT), these membranes have mostly been used in different soils in other regions of the world. Now for the first time, their impact was modeled for Africa. Projected results showed that the SWRT could increase maize yields in the eight African countries in the study by close to 50 percent and capture some 15 million tons of carbon in 20 years.

“With this new technology, sandy soil has the potential to lead a new green revolution,” said George Nyamadzawo, a professor at Bindura University in Zimbabwe.

The researchers said this simple technology, if deployed and adopted at scale, could address major issues facing sub-Saharan African farmers, including food security and erratic rainfall patterns, while also helping countries meet climate change mitigation targets. The study was published in Frontiers in Sustainable Food Systems in in September.

“We should refuse to allow sandy soils to limit smallholder farmers from reaching their full potential,” said Ngonidzashe Chirinda, a researcher at the International Center for Tropical Agriculture (CIAT) who co-authored the research. “In arid and semiarid regions with poor soils, smallholder communities continue to suffer due to soil-based poverty. Our research shows SWRT has the potential to effectively change this without recurring to traditional and potentially expensive remedies.”

For the study, SWRT was modeled for the sandy soils of eight countries in Southern Africa and Eastern Africa: Angola, Botswana, Kenya, Namibia, Mozambique, South Africa, Tanzania, and Zimbabwe. The main objective of the study was to model scenarios of adoption of SWRT and estimate increases in maize yields, crop biomass, and soil carbon sequestration.

Co-authors include scientists at the Swedish University of Agricultural Sciences (SLU), in Sweden; Jomo Kenyatta University of Agriculture and Technology, in Kenya; Cape Peninsula University of Technology, in South Africa; Bindura University of Science Education, in Zimbabwe; and Michigan State University (MSU), in the United States.

“Potential benefits are obvious with new technologies such as SWRT, but there is a need to overcome non-technical barriers; this requires support from decision-makers who can put in place the necessary policies and financial mechanisms to support farmer adoption,” said Libère Nkurunziza, the lead author and researcher at SLU. “Similar technologies should be tested and adapted to smallholder farmer conditions to solve productivity challenges on sandy soils.”

Using data collected in other regions where SWRT has been tested, the authors made their projections for Africa. The technology is now being tested in Zimbabwe, through a new Swedish Research Council-funded project, called Productive Sands, that is being led by SLU.

“The new innovative, long-term SWRT will lead the way for modifying soils that best assist plant resilience to changing climates and associated weather patterns, enabling smallholder farmers of sandy soils to establish reasonable nutritious food supplies and annual income across all nations,” said Alvin Smucker, a co-author from MSU and one of the pioneers of the technology.

Learn more: No soil left behind: How a cost-effective technology can enrich poor fields

 

The Latest on: Water retention technology

via  Bing News

 

Kilometer long threads of artificial spider silk

Figure 1. Biomimetic spinning of artificial spider silk.
a) Highly concentrated spider silk protein solution in a syringe is pumped through a pulled glass capillary with a tip size of 10-30 micrometre, with the tip submerged into a low pH aqueous collection bath. Fibers can be taken up from the collection bath (arrow) and rolled up onto frames. Photo: Marlene Andersson, Swedish University of Agricultural Sciences/Nature Chemical Biology
b) Photo of a fiber as it is spun in the low pH aqueous collection bath. Photo: Marlene Andersson, Swedish University of Agricultural Sciences/Nature Chemical Biology
c) Wet fiber nest in low pH buffer. Photo: Lena Holm, Swedish University of Agricultural Sciences/Nature Chemical Biology
d) As-spun fibers on a frame. Photo: Marlene Andersson, Swedish University of Agricultural Sciences/Nature Chemical Biology
Fiber diameter in (b-c) is approximately 40 micrometre and in (d) 15 micrometre. Scale bar in (a) 3 cm, (b) 3 mm, and (c-d) 5 mm.

Being able to produce artificial spider silk has long been a dream of many scientists, but all attempts have until now involved harsh chemicals and have resulted in fibers of limited use. Now, a team of researchers from the Swedish University of Agricultural Sciences and Karolinska Institutet has, step by step, developed a method that works.

Today they report that they can produce kilometer long threads that for the first time resemble real spider silk.Spider silk is an attractive material–it is well tolerated when implanted in tissues, it is light-weight but stronger than steel, and it is also biodegradable. However, spiders are difficult to keep in captivity and they spin small amounts of silk. Therefore, any large scale production must involve the use of artificial silk proteins and spinning processes. A biomimetic spinning process (that mimics nature) is probably the best way to manufacture fibers that resemble real spider silk. Until now, this has not been possible because of difficulties to obtain water soluble spider silk proteins from bacteria and other production systems, and therefore strong solvents has been used in previously described spinning processes.

Spider silk is made of proteins that are stored as an aqueous solution in the silk glands, before being spun into a fiber. Researcher Anna Rising and her colleagues Jan Johansson and Marlene Andersson at the Swedish University of Agricultural Sciences and at Karolinska Institutet have previously shown that there is an impressive pH gradient in the spider silk gland, and that this well-regulated pH gradient affects specific parts of the spider silk proteins and ensures that the fiber forms rapidly in a defined place of the silk production apparatus.

This knowledge has now been used to design an artificial spider silk protein that can be produced in large quantities in bacteria, which makes the production scalable and interesting from an industrial perspective.

“To our surprise, this artificial protein is as water soluble as the natural spider silk proteins, which means that it is possible to keep the proteins soluble at extreme concentrations”, says Anna Rising.

To mimic the spider silk gland, the research team constructed a simple but very efficient and biomimetic spinning apparatus in which they can spin kilometer-long fibers only by lowering the pH.

“This is the first successful example of biomimetic spider silk spinning. We have designed a process that recapitulates many of the complex molecular mechanisms of native silk spinning. In the future this may allow industrial production of artificial spider silk for biomaterial applications or for the manufacture of advanced textiles”, says Anna Rising.

Learn more: Spinning spider silk is now possible

 

 

 

Receive an email update when we add a new SPIDER SILK article.

 

The Latest on: Artificial spider silk

via  Bing News

 

Microplastics in agricultural soils: A reason to worry?

Oceans are not the only receivers of microplastics. (Photo: Wikimedia Commons)

Oceans are not the only receivers of microplastics. (Photo: Wikimedia Commons)

Microplastics are increasingly seen as an environmental problem of global proportions. While the focus to date has been on microplastics in the ocean and their effects on marine life, microplastics in soils have largely been overlooked. Researchers are concerned about the lack of knowledge regarding potential consequences of microplastics in agricultural landscapes from application of sewage sludge.

Microplastics are tiny plastic particles (1?m – 5 mm) which originates from degeneration of car tires, domestic goods, industrial processes and from degeneration of surfaces composed of, or coated with, plastics, i.e. artificial grass. Most of these particles originate in urban areas. In most developed regions, urban run-off water ends up in sewage treatment plants.

Sewage sludge is in principle waste, but it can also represent a resource in agriculture and horticulture. Fertilizer based on sludge contains valuable nutrients, but sustainable use requires that the levels of undesirable substances in the sludge is kept under control. Waste water treatment plants receive large amounts of microplastics emitted from households, industry and surface run-off in urban areas. Most of these microplastics accumulate in the sewage sludge.

Today, sludge from municipal sewage treatment plants is applied to agricultural areas as a supplement to traditional fertilizers. These applications are generally well regulated as sludge might contain hazardous substances of different sorts. Microplastics are however not currently on the regulatory agenda for the use of sludge in agriculture. The potential consequences for sustainability and food security have not been adequately analyzed.

These concerns have been expressed in an article recently published in the journal Environmental Science & Technology. The researchers behind the article are Luca Nizzetto and Sindre Langaas from the Norwegian Institute for Water Research (NIVA) and Martyn Futter from the Swedish University of Agricultural Sciences (SLU) in Uppsala.

Unknown consequences

– We have found figures from the Nordic countries suggesting that a large fraction of all the microplastics generated in Western societies tend to end up in the sludge in wastewater treatment plants, says Nizzetto. Via the sludge the particles are transferred to agricultural soils.

The amount of sewage sludge used as fertilizer varies greatly from country to country. In Europe and North America approximately 50 % of this sludge is reused as fertilizer on average. According to Statistics Norway, about two thirds of the sludge is reused in this manner.

– Our estimates suggest that between 110.000 and 730.000 tons of microplastics are transferred every year to agricultural soils in Europe and North America, comprehensively. This is more than the estimated total burden of microplastics currently present in ocean water.

These figures are of concern since the effects of microplastics accumulating in agricultural soils are unknown.

– We have very little knowledge on the effect of microplastics on soil organisms, and their impact on farm productivity and food safety is unknown.

Microplastics are tiny plastic particles which originates from household articles, industrial processes and degeneration of plastic products. (Photo: Oregon State University)

The first simulation of microplastic fate on land and rivers

In an earlier study from the same authors, and researchers of Oxford University, the first mathematical model describing the dynamics of microplastics’ fate in terrestrial environments and rivers was presented. Due to a lack of empirical data on microplastics emissions and concentrations in soils and the stream system, this study was conceived to provide a purely theoretical, nevertheless rigorous, assessment of microplastics circulation.

The model is called INCA Microplastics, and simulations have showed a strong influence of meteorological conditions and river characteristics and flows in controlling the export of microplastics from agricultural soils and their transport to the ocean. Application of sewage sludge to soils likely represent a considerable source of microplastics to the coastal and ocean environments. Similar predictions for the transport of microplastics in rivers were independently confirmed by a follow-up study by Besseling et al.

INCA Microplastics is an important tool for risk assessment and evaluating sludge management scenarios. It is the first model able to simulate microplastic applications to land, and the consequent fate of these materials in soils and surface waters.

>> Read more: A new “high-resolution” computer simulator to predict future environmental pollution scenarios

Surprising knowledge gap

The consequences of transfers of microplastics from urban waste water to agricultural soil barely have been considered by researchers and authorities, particularly in lieu of the extended attention directed at microplastics in the ocean.

– Clearly further research is needed to get an overview of the problem – and to find solutions – so that the growing need in the community for recycling and so-called circular economy can be safeguarded, Luca Nizzetto says.

Learn more: Microplastics in agricultural soils: A reason to worry?

 

 

The Latest on: Microplastics in agricultural soils

via  Bing News

 

Edible crickets can be reared on weeds and cassava plant tops

Deep fried corn tortillas with garlic fried house crickets, white bean mash with smoked garlic, rocoto salsa, epazote, and avocado, salsa verde, onion and cilantro. Photo: Jenny Svennås-Gillner

Deep fried corn tortillas with garlic fried house crickets, white bean mash with smoked garlic, rocoto salsa, epazote, and avocado, salsa verde, onion and cilantro. Photo: Jenny Svennås-Gillner

To become a sustainable alternative to meat, reared crickets must be fed feeds other than the chicken feed that is most commonly used today.

Researchers from the Swedish University of Agricultural Sciences now present a study which shows that there are weeds and agricultural by-products that actually work as single ingredients in feeds for crickets. The study was conducted in Cambodia, where many children suffer from malnutrition and where the need for cheap protein is large.

The study was led by Anna Jansson, professor of animal physiology at the Swedish University of Agricultural Sciences. The results have very recently been published in the Journal of Insects as Food and Feed.

“Since there are both climate and environmental benefits of eating insects, we believe that this habit will become more common, also in Western countries. What our study shows is that it is possible to rear crickets on feeds that don’t compete with other kinds of food production”, says Anna Jansson.

Reared insects are increasingly seen as an environmentally friendly alternative to meat, even by the United Nations. The future food for a growing world population.

In the Western world there is a cultural reluctance to eating insects, but also a cautious curiosity, and there is an increasing interest among scientists. In other parts of the world, such as Asia, there is a tradition to eat insects, and some species are regarded as delicacies. Many insects also seem to have a high nutritional value. So far, people mainly catch wild insects, but rearing them is emerging as a way to meet the growing demand.

Crickets are prized as food and they also seem to be quite easy to rear. Today crickets are usually reared on chicken feed, and this production has limited environmental benefits compared to chicken production, since crickets and chickens grow equally well on this feed. Also, this feed is too expensive for poor people, and its nutritional value is so high that people could just as well eat it themselves.

To be a climate and environmentally smart food, crickets have to be reared on feeds that have little value in other kinds of agricultural production, such as residues or weeds, and they must be cheap enough for poor people. Scientists know that many cricket species can feed on “a little of everything” but very few attempts have been made to rear crickets on residues, and none using weeds.

What Anna Jansson and her colleagues now show is that there are weeds and residues that perform as well as chicken feed for the Cambodian field cricket. Now their recommendations are passed on to people who want to rear crickets in Cambodia.

A number of Cambodian weeds and various residues from agricultural and other food production were tested in the study. Today these commodities are available for free or nearly free, which means that even very poor people would be able to rear crickets, at least to cover their own family’s needs. The best ingredients were cassava tops and the weed Cleome rutidosperma (Fringed Spider Flower or Purple Cleome), both of which could be used as a single ingredient cricket feed.

Background to the project

Cambodia is one of the world’s poorest countries. It is estimated that 40 percent of Cambodian children under the age of 5 suffer from malnutrition, which inhibits both their physical and mental development. The Swedish University of Agricultural Sciences has for many years run Sida-funded PhD projects in developing countries, and this project is one example.

Learn more: Edible crickets can be reared on weeds and cassava plant tops

 

 

The Latest on: Alternative to meat

via  Bing News

 

Tiny grains of rice hold big promise for greenhouse gas reductions, bioenergy

In addition to a near elimination of greenhouse gases associated with its growth, SUSIBA2 rice produces substantially more grains for a richer food source. The new strain is shown here (right) compared to the study's control. Image courtesy of Swedish University of Agricultural Sciences

In addition to a near elimination of greenhouse gases associated with its growth, SUSIBA2 rice produces substantially more grains for a richer food source. The new strain is shown here (right) compared to the study’s control.
Image courtesy of Swedish University of Agricultural Sciences

Discovery delivers high starch content, virtually no methane emissions

Rice serves as the staple food for more than half of the world’s population, but it’s also the one of the largest manmade sources of atmospheric methane, a potent greenhouse gas. Now, with the addition of a single gene, rice can be cultivated to emit virtually no methane from its paddies during growth. It also packs much more of the plant’s desired properties, such as starch for a richer food source and biomass for energy production, according to a study in Nature.

With their warm, waterlogged soils, rice paddies contribute up to 17 percent of global methane emissions, the equivalent of about 100 million tons each year. While this represents a much smaller percentage of overall greenhouse gases than carbon dioxide, methane is about 20 times more effective at trapping heat. SUSIBA2 rice, as the new strain is dubbed, is the first high-starch, low-methane rice that could offer a significant and sustainable solution.

Researchers created SUSIBA2 rice by introducing a single gene from barley into common rice, resulting in a plant that can better feed its grains, stems and leaves while starving off methane-producing microbes in the soil.

The results, which appear in the July 30 print edition of Nature andonline, represent a culmination of more than a decade of work by researchers in three countries, including Christer Jansson, director of plant sciences at the Department of Energy’s Pacific Northwest National Laboratory and EMSL, DOE’s Environmental Molecular Sciences Laboratory. Jansson and colleagues hypothesized the concept while at the Swedish University of Agricultural Sciences and carried out ongoing studies at the university and with colleagues at China’s Fujian Academy of Agricultural Sciences and Hunan Agricultural University.

“The need to increase starch content and lower methane emissions from rice production is widely recognized, but the ability to do both simultaneously has eluded researchers,” Jansson said. “As the world’s population grows, so will rice production. And as the Earth warms, so will rice paddies, resulting in even more methane emissions. It’s an issue that must be addressed.”

Read more: Tiny grains of rice hold big promise for greenhouse gas reductions, bioenergy

 

The Latest on: SUSIBA2 rice
  • Addition of a single gene makes rice more environmentally friendly
    on August 8, 2015 at 5:00 pm

    The PNNL team reasoned that if they could persuade rice to act more like other cereals, it would not only increase yields, but also help cut down on methane emissions. SUgar SIgnaling in BArley 2 ...

  • Grains of rice hold big promise for GHG reductions, bioenergy
    on August 5, 2015 at 3:54 pm

    SUSIBA2 rice, as the new strain is dubbed, is the first high-starch, low-methane rice that could offer a significant and sustainable solution. Researchers created SUSIBA2 rice by introducing a single ...

  • Tiny grains of rice hold big promise for greenhouse gas reductions, bioenergy
    on July 29, 2015 at 12:01 pm

    SUSIBA2 rice, as the new strain is ... Tiny grains of rice hold big promise for greenhouse gas reductions, bioenergy: Discovery delivers high starch content, virtually no methane emissions.

  • Tiny grains of rice hold big promise for greenhouse gas reductions, bioenergy
    on July 29, 2015 at 9:12 am

    SUSIBA2 rice, as the new strain is dubbed, is the first high-starch, low-methane rice that could offer a significant and sustainable solution. Researchers created SUSIBA2 rice by introducing a single ...

  • SUSIBA2 Rice Compared to Control (image)
    on July 29, 2015 at 8:50 am

    In addition to a near elimination of greenhouse gases associated with its growth, SUSIBA2 rice produces substantially more grains for a richer food source. The new strain is shown here (right) ...

  • Tiny grains of rice hold big promise for greenhouse gas reductions, bioenergy
    on July 27, 2015 at 5:00 pm

    In addition to a near elimination of greenhouse gases associated with its growth, SUSIBA2 rice produces substantially more grains for a richer food source. The new strain is shown here (right) ...

  • New GM rice "can cut greenhouse emission"
    on July 23, 2015 at 2:25 am

    By inserting a barley gene into rice, Sun Chuanxin and his colleagues created SUSIBA2 Rice, which stores more starch in the section of the rice above ground, according to a paper published on the ...

  • Scientists create low-methane rice
    on July 22, 2015 at 2:48 pm

    Groundbreaking' work - Tackling the problem differently, a team from China, the United States and Sweden added a barley gene to a conventional rice cultivar to create a variety dubbed SUSIBA2.

  • Scientists create low-methane rice
    on July 21, 2015 at 5:00 pm

    Tackling the problem differently, a team from China, the United States and Sweden added a barley gene to a conventional rice cultivar to create a variety dubbed SUSIBA2. "Three-year field trials in ...

  • Bypassing the methane cycle
    on July 21, 2015 at 5:00 pm

    Although Su and colleagues have made the groundbreaking demonstration that high-starch, low-methane rice plants can be generated, their study raises many issues. The most obvious is that SUSIBA2 rice ...

via  Bing News