This year’s wheat harvest is currently underway across the country after a difficult growing season, with harvest itself being delayed due to intermittent stormy weather. The high levels of rainfall at the start of the growing season meant that less winter wheat could be planted and dry weather in April and May caused difficulties for spring wheat as well. This decline in the wheat growing area has caused many news outlets to proclaim the worst wheat harvest in 40 years and potential bread price rises.
Difficult weather during this year’s growing season. Photo: Joe Oddy
This is also the first wheat harvest in which I have a more personal stake, namely the first field trial of my PhD project; looking at how asparagine levels are controlled in wheat. It seemed like a bad omen that my first field trial should coincide with such a poor year for wheat farming, but it is also an opportunity to look at how environmental stress is likely to influence the nutritional quality of wheat, particularly in relation to asparagine.
The levels of asparagine, a nitrogen-rich amino acid, in wheat grain have become an important quality parameter in recent years because it is the major determinant and precursor of acrylamide, a processing contaminant that forms during certain cooking processes. The carcinogenic risk associated with dietary acrylamide intake has sparked attempts to reduce consumption as much as possible, and reducing asparagine levels in wheat is a promising way of achieving part of this goal.
Asparagus, from which asparagine was first discovered and named.
Previous work on this issue has shown that some types of plant stress, such as sulphur deficiency, disease, and drought, increase asparagine levels in wheat, so managing these stresses with sufficient nutrient supply, disease control, and irrigation can help to prevent unwanted asparagine accumulation. Stress can be difficult to prevent even with such crop management strategies though, especially with environmental variables as uncontrollable as the weather, so it is tempting to speculate that the difficulties experienced this growing season will be reflected in higher asparagine levels; but we will have to wait and see.
Soil is a very precious asset whether it be in your garden or an allotment. Soil has physical and chemical properties that support its biological life. Like any asset understanding its properties is fundamental for its effective use and conservation.
Soils will contain, depending on their origin four constituents: sand, clay, silt and organic matter. Mineral soils, those derived by the weathering of rocks contain varying proportions of all four. But their organic matter content will be less than 5 percent. Above that figure and the soil is classed as organic and is derived from the deposition of decaying plants under very wet conditions forming bogs.
Essentially this anaerobic deposition produces peat which if drained yields highly fertile soils such as the Fenlands of East Anglia. Peat’s disadvantage is oxidation, steadily the organic matter breaks down, releases carbon dioxide and is lost revealing the subsoil which is probably a layer of clay.
Cracked clay soil
Mineral soils with a high sand content are free draining, warm quickly in spring and are ‘light’ land. This latter term originates from the small number of horses required for their cultivation. Consequently, sandy soils encourage early spring growth and the first crops. Their disadvantage is limited water retention and hence crops need regular watering in warm weather.
Clay soils are water retentive to the extent that they will become waterlogged during rainy periods. They are ‘heavy’ soils meaning that large teams of horses were required for their cultivation. These soils produce main season crops, especially those which are deeply rooting such as maize. But in dry weather they crack open rupturing root systems and reducing yields.
Silt soils contain very fine particles and may have originated in geological time by sedimentation in lakes and river systems. They can be highly fertile and are particularly useful for high quality field vegetable and salad crops. Because of their preponderance of fine particles silt soils ‘cap’ easily in dry weather. The sealed surface is not easily penetrated by germinating seedlings causing erratic and patchy emergence.
Soil finger test
Soil composition can be determined by two very simple tests. A finger test will identify the relative content of sand, clay and silt. Roll a small sample of moist soil between your thumb and fingers and feel the sharpness of sand particles and the relative slipperiness of clay or the very fine almost imperceptible particles of silt. For a floatation test, place a small soil sample onto the top of a jam jar filled with water. Over 24 to 48 hours the particles will sediment with the heavier sand forming the lower layer with clay and silt deposited on top. Organic matter will float on the surface of the water.
Soil floatation test
Transferring plants between countries was a profitable source for novel commercial and garden plants until quite recently.
Potato crop: Geoff Dixon
Potatoes and tomatoes are classic examples arriving in Europe from South America during the 16th century. Substantial numbers of new plants fuelled empire expansion founding new industries such as rubber and coffee. One of the earliest functions of European botanic gardens was finding potentially valuable new crops for colonial businesses. At home selecting orchids and other exotics from imported plants brought fame and fortune for head gardeners managing the large 19th century estates such as Chatsworth. Commercially seed merchants selected by eye and feel new and improved vegetables, fruit and flowers.
The rediscovery of Mendel’s laws of inheritance brought systematic science and formalised breeding new crops and garden plants. Analysing the effects of transferring physical, chemical and biological characters identified gene numbers and their functions.
Colour range in Gladioli: Geoff Dixon
As a result, varieties with improved colourfulness, fruitfulness, yield and pest and pathogen tolerance fill seedsmen’s catalogues. Breeding increased food supplies and added colour into the gardens springing up in suburban areas as affluence increased.
Greater plant reliability and uniformity arrived with the discovery of F1 hybrids.
Hybrid Sunflowers: Geoff Dixon
Selected parental lines each with very desirable characters such as fruit colour are in-breed for several generations. Then they are crossed bringing an explosion of vigour, uniformity and reliability (known as heterosis). Saving seed from the hybrid lines does not however, perpetuate these characters; new generations come only from remaking the original cross. That is a major boon for the breeder as competitors cannot pirate their intellectual property.
Knowledge at the molecular level has unravelled still further gene structure and functioning. Tagging or marking specific genes with known properties shortens the breeding cycle adding reliability and accuracy for the breeder. Simplifying the volume of genetic material used in crosses by halving the number of chromosomes involved adds further precision and control (known as haploidisation).
Opportunities for breeding new plants increases many-fold when advantageous genes are transferred between species. Recent developments of gene-editing where tailored enzymes very precisely snip out unwanted characters and insert advantageous ones is now offering huge opportunities as a non-transgenic technology. Breeding science makes possible mitigation of climate change, reducing for example the impact of soil degradation brought about by flooding.
Flood degraded land: Geoff Dixon
The European Court of Justice (ECJ) ruled in July 2018 that onerous EU regulations for GMOs should also be applied to gene edited crops. The ECJ noted that older technologies to generate mutants, such as chemicals or radiation, were exempt from the 2001 GMO directive, but all other mutated crops should be regarded as GMOs. Since gene editing does not involve foreign DNA, most plant scientists had expected it to escape GMO regulations.
‘We didn’t expect the ruling to be so black and white and prescriptive,’ says Johnathan Napier, a crop scientist at Rothamsted Research. ‘If you introduce a mutant plant using chemical mutagenesis, you will likely introduce thousands if not millions of mutations. That is not a GMO. But if you introduce one mutation by gene editing, then that is a GMO.’
What is genetic modification? Video: The Royal Society
The ECJ ruling will have strong reverberations in academe and industry. The European Seed Association described the ruling as a watershed moment. ‘It is now likely that much of the potential benefits of these innovative methods will be lost for Europe – with significant economic and environmental consequences,’ said secretary general Garlich von Essen.
In 2012, BASF moved its plant research operations to North Carolina, US, because of European regulations. ‘If I was a company developing gene editing technologies, I’d think of moving out of Europe,’ says Napier.
‘The EU is shooting itself in the foot. Its ag economy has been declining since 2005 and it has moved from net self-sufficiency to requiring imports of major staples,’ says Maurice Moloney, CEO of the Global Institute for Food Security in Saskatchewan, Canada. ‘Paradoxically, it still imports massive quantities of GM soya beans and other crops to feed livestock.’
Combatting malnutrition in all its forms – overweight and obesity as well as undernutrition and micronutrient deficiencies – is a global problem.
The European Academies Science Advisory Council (EASAC) recently published a report calling for urgent action on food and nutrition security: this action will need to include consideration of the options for changing European diets to mitigate climate change, conferring co-benefits for health.
The European Commission estimates 51.6% of the EU’s population is overweight. Image: Tony Alter/Flickr
EASAC brings together EU member states’ national science academies with the aim of offering evidence-based advice to European policy makers. EASAC provides a means for the collective voice of European science to be heard and its recent report is part of a global project led by the InterAcademy Partnership (IAP).
The analysis and recommendations for Europe are accompanied by parallel activities focusing on Africa, Asia and the Americas. The IAP report will be published later in 2018.
EASAC recommendations will incorporate global challenges and needs, not just those in Europe. Image: Pixabay
In the EASAC report we emphasise that research and innovation are central to finding solutions. We recommend being more ambitious in identifying and using scientific opportunities: How can the current evidence base shape understanding of both supply- and demand-side challenges? And how should the research agenda be defined, including basic research, to fill knowledge gaps?
Climate change will have negative impacts on food systems, necessitating the introduction of climate-smart agriculture such as the adoption of plant breeding innovations to cope with drought.
Climate-Smart Agriculture in Action. Video: Farming First
Agriculture and current diets also contribute significantly to climate change. Mitigating this contribution depends on land-sparing and agronomic management practices together with efforts to influence consumer behaviours associated with excessive greenhouse gas emissions from agriculture, including the over-consumption of calories and meat.
Among the core findings in our report is that food consumption will need to change to improve consumer health. It is important to explore individual responsiveness to nutrition and the links to health, and to consider the particular needs of vulnerable groups.
High meat production has been linked to increasing carbon emissions. Image: Pixabay
As part of the changes to food consumption patterns, a decrease in the consumption of animal protein could be important for both health and the environment but, globally, more research is needed to clarify these relationships and to measure sustainability related to consumption of healthy diets. We also call for policy makers to introduce incentives for affordable nutrition.
Agriculture has significant impacts on the environment. We call for the revamp of the Common Agricultural Policy to focus on innovation rather than subsidies, in order to play a key role in European competitiveness and the bioeconomy.
Alternatives to traditional forms of animal protein include food from the oceans, laboratory-grown meat and insects. Research is needed to understand and inform consumer attitudes to innovative food and diets.
Also, research objectives for the next generation of biofuels should include examining the potential of cellulosic raw materials. Further ahead, energy research must continue to explore how to engineer systems with improved photosynthesis.
Biofuels are derived from common crops, including wheat, corn and sugar. Image: Public Domain Pictures
Europe should not stall on opportunities for innovation coming within range. Breakthroughs in genome editing and other genetic research are crucial to the future of agriculture. European policy makers must capitalise on these scientific advances.
For improved plant and animal breeding, it is important to protect and characterise wild gene pools and to continue sequencing and functional assessment to unveil the potential of genetic resources. Precision agriculture offers many opportunities to improve productivity with reduced environmental impact. Large data sets are vital to support innovation and prepare for risk and uncertainty.
Open-source automated precision farming | Rory Aronson | TEDxUCLA. Video: TEDx Talks
Underpinning all our recommendations is the recognition that research and innovation must be better integrated, across disciplines and the public and private sectors, in order to better understand the interfaces between health, nutrition, food and other ecosystem services.
EASAC emphasises that efforts to increase food systems’ efficiency should not focus on increasing agricultural productivity by ignoring environmental costs.
A new type of wheat, chock full of healthy fibre, has been launched by an international team of plant geneticists. The first crop of this super wheat was recently harvested on farms in Idaho, Oregon, and Washington state in the US, ready for testing by various food companies.
Food products are expected to hit the US market in 2019. They will be marketed for their high content of ‘resistant starch’, known to improve digestive health, be protective against the genetic damage that precedes bowel cancer, and help protect against Type 2 diabetes.
How do carbohydrates impact your health? Video: TED-Ed
‘The wheat plant and the grain look like any other wheat. The main difference is the grain composition: the GM Arista wheat contains more than ten times the level of resistant starch and three to four times the level of total dietary fibre, so it is much better for your health, compared with regular wheat,’ says Ahmed Regina, plant scientist at Australian science agency CSIRO.
Starch is made up of two types of polymers of glucose – amylopectin and amylose. Amylopectin, the main starch type in cereals, is easily digested because it has a highly branched chemical structure, whereas amylose has a mainly linear structure and is more resistant.
Bread and potatoes are foods also high in starch. Image: Pixabay
Breeders drastically reduced easily digested amylopectin starch by downregulating the activity of two enzymes, so increasing the amount of amylose in the grain from 20 to 30% to an impressive 85%.
The non-GM breeding approach works because the building blocks for both amylopectin and amylose starch synthesis are the same. With the enzymes involved in making amylopectin not working, more blocks are then available for amylose synthesis.
‘Resistant starch is starch that is not digested and reaches the large intestines where it can be fermented by bacteria. Usually amylose is what is resistant to digestion,’ comments Mike Keenan, food and nutrition scientist at Louisiana State University, US. ‘Most people consume far too little fibre, so consuming products higher in resistant starch would be beneficial.’
He notes that fermentation of starch in the gut causes the production of short-chain fatty acids such as butyrate that ‘have effects throughout the body, even the mental health of humans’.
The GM wheat will hit US supermarkets in 2019. Image: Pxhere
The super-fibre wheat stems from a collaboration begun in 2006 between French firm Limagrain Céréales Ingrédients, Australian science agency CSIRO, and the Grains Research and Development Corporation, an Australian government agency.
This resulted in a spin out company, Arista Cereal Technologies. After the US, Arista reports that the next markets will be in Australia and Japan.
The Haber process currently helps feed more than half the world, producing 150m tonnes of ammonia a year. This is forecast to rise further, in line with the food demand of a growing world population.
And yet, it has serious drawbacks. In its traditional form, the process requires high temperatures – around 500°C – to make the extremely stable molecule nitrogen reactive.
The Haber process takes place at extremely high temperatures, similar to that of an average fire.
It also needs high pressure to shift the equilibrium towards the desired product. The process is sensitive to oxygen, meaning that nitrogen and hydrogen must be introduced as purified elements, rather than as air and water.
These requirements together make the process extremely energy-hungry; estimated to consume between 1% and 2% of global primary energy production. In 2010, the ammonia industry emitted 245m tonnes of CO2 globally, corresponding to half the UK’s emissions.
The Haber process was developed by Carl Bosch (left) and Fritz Haber (right) in the early 20th century. Image: Wikimedia Commons
In nature, the process relies on the highly complex enzyme nitrogenase, operating at an ambient pressure and temperature. But using the entire biological system would not be economical for large-scale industrial synthesis, and thus the search for an inorganic system that matches the performance of the biological has become an important challenge.
In recent years, novel electrochemical approaches and new catalysts have yielded promising results suggesting that, at least for small-scale synthesis, other ways may have a future.
The chemical reaction that feeds the world. Video: TED-Ed
‘The last [few] years brought some spectacular results on ammonia synthesis research,’ comments Hans Fredriksson from Syngaschem at Eindhoven, Netherlands.
‘On the catalyst side, there is the discovery of ‘super promoters’, helping N2 dissociation, allowing lower process temperatures, while optimised catalyst formulations yield significant improvements in activity.
‘Perhaps even more exciting are new approaches in processing, for example by electrochemistry, or simply running the reaction in an electric field, or bringing plasmas into play,’ he said.
In 2013, Shanwen Tao, then at the University of Strathclyde, Glasgow, UK, and colleagues demonstrated for the first time the production of ammonia from air and water, at ambient temperature and pressure, using a proton-conducting Nafion membrane in an electrochemical approach.
Nafion, a Teflon-like material that conducts cations but neither electrons nor anions, is also used in fuel cells.
‘Electrochemical synthesis of ammonia is an important new approach for efficient synthesis of ammonia using green renewable electricity as the energy source. This could be a key technology for a possible ‘ammonia economy’,’ where ammonia replaces or complements hydrogen as an energy carrier, says Tao.
Researchers hope new approaches will be supported by renewable energy, reducing CO2 emissions. Image: Pexels
Separate efforts using different routes are being developed in Japan, with a particular focus on ruthenium as an efficient catalyst. One approach is to apply super promoters to provide electrons that destabilise nitrogen by weakening the triple bond and making the molecule more reactive for ammonia synthesis.
This was first reported in 2012 by Hideo Hosono’s group at the Tokyo Institute of Technology, who used ruthenium catalysts in combination with ‘electrides’ – a new class of ionic materials where electrons serve as the anions.
The method operates at atmospheric pressure and temperatures between 250 and 400°C, and hydrogen poisoning of ruthenium catalysts is no longer a problem.
Ruthenium is a type of metal in the platinum group. Image: Metalle-w/ Wikimedia Commons
‘This catalyst exhibits the highest activity and excellent long-term stability,’ says Hosono, who sees the future of his methods in distributed, small-scale applications of ammonia synthesis.
Hans Niemantsverdriet, director of SynCat@Beijing, China, acknowledges the rapid progress being made, but also strikes a note of caution.
‘In spite of interesting discoveries, I find it hard to imagine that these improvements will be able to replace the current large-scale and fully optimised technology,’ he says. ‘In the fertiliser area, novel technology will at best become a niche market for very special situations. Also, the CO2 footprint is hardly diminished.’
Ammonia is a core component of fertiliser, feeding nitrogen to plants for photosynthesis. Image: Maurice van Bruggen/Wikimedia Commons
In the long term, Niemantsverdriet has hope for the ammonia economy as championed by Tao and others, providing carbon-free hydrogen from renewable energies.
‘I strongly believe that there will be scope for large industrial parks where this technology can be cleverly integrated with gasification of coal in China, and perhaps biomass elsewhere,’ he says. ‘If dimensioned properly, this has the potential to reduce the carbon footprint in the future.’
Russian researchers have developed new fertilisers based on nanopowders of transition metals. In field trials on agricultural crops, harvests increased by more than a quarter, compared with conventional fertilisers.
Iron, cobalt and copper affect a plant’s level of resistance to pests and diseases. These microelements are typically introduced into the soil as soluble salts, but rain and irrigation can wash them away, requiring further applications. They also have potential to disrupt local ecosystems as they pass into the groundwater.
An irrigation system in Idaho, US. Image: Jeroen Komen@Wikimedia Commons
The team, led by the National University of Science and Technology (NUST) in Moscow, has developed a group of fertilisers that are applied as a powder to plant seeds, without losses to the soil or water systems. In this way, ‘the future plant is provided with a supply of necessary microelements at the stage of seeding,’ reports Alexander Gusev, head of the project at NUST’s Department of Functional Nanosystems.
‘[It’s] a one-seed treatment by a product containing the essential microelements in nanoform. These particles of transition metals – iron, copper, cobalt – have a powerful stimulating effect on plant growth in the initial growth phase.’
Gusev reports improved field germination and increased yields of 20-25%.
The main difficulty was to produce a powder from the nanoparticles, which tended to quickly stick together as aggregates, says Gusev – a problem they solved by using organic stabilisers and then subjecting the colloidal solutions to ultrasonic processing.
Gusev now wants to discvover how the new fertiliser acts in different soils, and in relation to different plant cultures. Its environmental safety also needs to be evaluated before widespread use, he adds.
But Steve McGrath, head of sustainable agricultural sciences at Rothamsted Research, is sceptical. Plants are adapted to take up ionic forms of these microelements, not nanoparticles, he says. ‘Also, seeds do not take up much micronutrients. Roots do that, and depending on the crop and specific nutrient, most uptake is near to the growing ends of the root, and throughout the growing season, when the seed and nearby roots are long gone.’
Critics are skeptical of the efficacy of the new kind of fertiliser. Image: Pexels
If there is an effect on crop yield, he thinks it is more likely to be due to the early antifungal and antibacterial effects of nanoparticles. ‘They have a large and highly reactive surface area and if they are next to membranes of pathogens when they react they generate free radicals that disrupt those membranes. So, in a soil that is particularly disease-infected, there may be some protection at the early seedling stage.’
A world with a rapidly increasing population needs a rapidly increasing food supply. However, with a limited amount of land to work with, farmers must maximise agricultural production on the land they have available.
Modern-day intensive agriculture techniques include mechanical ploughing, chemical fertilisers, plant growth regulators, pesticides, biotech, and genetic modification.
1. Crop production has rapidly expanded in the past few centuries
Farming has drastically changed since the time this picture was taken at the California Manzanar Relocation Centre in 1943. Image: Ansel Adams
Worldwide, the amount of cultivated land increased 466% between 1700 and 1980, with global food production doubling four times between 1820 and 1975. In 1940, the average farmworker supplied 11 consumers; in 2006, each supplied 144 customers. Two out of five American labourers were farmers in 1900, but now only one in 50 work in agriculture. In 1830, five acres of wheat took 250-300 hours of work to produce. By 1975, it only took 3¾ hours.
2. Crops can be grown without soil
Organic hydroponic culture in Ho Chi Minh, Vietnam. Image: Frank Fox
Using a crop-growing method called hydroponics, instead of putting plants in soil, a mineral solution is pumped around the roots. This makes it possible to grow crops in regions with low-quality soil or none at all, increasing the amount of space that can be used for agriculture. This technique also allows for the nutrients to be effectively recycled and eliminates the risk of soil organisms that cause disease.
3. At least 90% of the soy, cotton, canola, corn, and sugar beets sold in the US are GMOs
Since the 1970s, scientists have been working on genetically modifying crops to make them tougher, disease-resistant, more nutritious, and higher yielding. Though the first commercially available GMO came onto the market just 23 years ago, global markets have already been transformed by the ground-breaking innovation.
4. Regenerative grazing increases the health and productivity of pastures
Image: Tom Koerner/USFWS
Regenerative grazing - staggering grazing on different plots of land according to a calendar – has proven to increase soil health. By allowing plots to rest after grazing, the soil and anything living in it is able to recover before the next time it is used. Regenerative grazing cultivates fields with less bare soil and increases populations of earthworms and soil organisms. Not only that, it also eliminates the need for chemical fertiliser, increases grass growth by 14%, and causes a 10% decrease in carbon footprint per litre of milk.
5. Agricultural robots are transforming the industry
If you’re interested in the issues surrounding global food sustainability, you can watch the full video of Sir John Beddington’s recent SCI Andrew Medal Lecture: ‘Global Sustainability Challenges: Food, Water, and Energy Security’, here.