Think of Earth as an apple and the soil as the peel. Now, imagine that more than 70% of this apple’s surface is covered in water. That veneer of peel suddenly seems very small indeed.
Dig beneath the surface and you realise that the world’s soil resources aren’t as plentiful as you first thought. When you take into account all of the uninhabitable, non-arable land on our planet, including the snow-bound poles and deserts, you’re left with just 3% of total landmass to grow all the fruit and vegetables we eat.
After reminding her listeners of some stark facts at the Soil resources in the UK: overlooked and undervalued? webinar, Jane Rickson, Professor of Soil Erosion and Conservation at Cranfield University, reminded us that soil is a precious, finite resource. “We’re dealing with a very thin resource that has to deliver all of these goods and services.”
You just need to think of your breakfast, lunch, and dinner to realise just how important soil is. Of all the food we eat, 97% comes from terrestrial sources. However, in recent decades, the many benefits brought by soil have been taken lightly. Apart from providing food, animal fodder, and a surface for football, it plays a vital role in climate change mitigation.
‘Soil is excellent for climate change mitigation,’ said Professor Rickson, recipient of the prestigious Dr Sydney Andrew Medal for 2021. ‘We know that healthy soils can support vegetation and crops and plants in taking out atmospheric CO2.’
A cross section of soil layers. Unless you live on fish and seaweed, it’s likely that almost all of your food sources will come from terrestrial sources.
However, she and her colleagues at Cranfield University have unearthed some unsettling facts about the state of our soils. She mentioned that 12 million hectares of agricultural land worldwide is lost each year due to soil degradation. In the UK, soil erosion rates can be as high as 15 tonnes per hectare per year, with soil formation rates only compiling at a rate of 1 tonne per hectare per year; and, based on current rates of erosion, some soils could disappear completely by 2050.
So, what is being done to arrest this problem? The obvious mammoth in the room is climate change, with extreme weather events such as flash floods precipitating a huge amount of soil erosion. Obviously, climate change mitigation measures on a national scale would help, but adjustments to farming practices could also improve soil resilience on a more local level.
A lot of work is also being done to reduce the intensity of farming to improve soil health. The aim, according to Rickson, is to maintain a fertile seedbed while retaining maximum resistance to soil degradation. There are lots of different ways to do this.
One approach being taken is cover cropping, whereby a crop is grown for the protection and enrichment of the soil rather than for immediate sale. This enriches the soil and helps prevent soil erosion. Another approach is strip-tillage – a minimum tillage system that disturbs only the portion of the soil that contains the seed row, with the soil between rows left untilled. She also mentioned the benefits of soil improvement, with poultry manure and mushroom compost used to improve soil health by Benedict Unagwu among others.
Cover crops such as vetch and oats improve the structure and fertility of the soil.
It is difficult not to have sympathy for farmers at the moment. Climate change falls heavily upon their lands, and they must battle flooding and drought to keep their farms financially viable. Professor Rickson often speaks to the farming community about soil health, with the focus placed on realistic solutions. As one farmer told her: ‘It's hard to be green when you’re in the red.’
Perhaps soil doesn’t capture the imagination the same way as an oak forest or a field ablaze with wildflowers, but its mismanagement is costing us a fortune. She estimated that the combined annual economic cost of soil degradation in England, Scotland, and Wales is £1.5 billion.
According to Professor Rickson, the US is probably the home of soil conservation following the harsh ecological lessons learnt from the Dust Bowl disaster of the 1930s. However, she believes the UK has plenty of knowhow in the area.
‘The UK has an opportunity to be world-leading in this,’ she said. ‘I think we are as good as anyone. Our scientific community understands soil and is really pushing the boundaries in terms of soil science.’
Farmers today are under pressure to produce more food with fewer resources and without damaging the environment around them. Faced with factors such as land pressures, soil fertility, pest management and agricultural policy, farming today is all about efficiency, time and energy saving technology, and the drive to make solutions as sustainable as possible.
This obviously poses the question: what can the agrochemical industry do to increase output on one hand and protect the environment and improve applicator safety on the other?
Formulation technology is becoming increasingly important in answering this question. By designing innovative formulations, agrochemical products can become more effective as well as safer. Without the right formulation, even the best active substance is worth nothing.
Most pesticidal active ingredients are not water soluble or water dispersible, yet the most common mode of delivery is via spray applications of aqueous dilutions. It is necessary to create a formulation of the active ingredient in a way that makes it easily dispersible in water and able to maintain stability over the application time period. Changing what goes into this formulation alongside the active ingredient is crucial in how effectively that material is delivered to where it needs to be.
Demonstration of an EC formulation.
Two of the most common types of agricultural formulations that tackle this issue are emulsifiable concentrates (ECs) and suspension concentrates (SCs). EC formulations are suited to active ingredients that are oil soluble and have low melting points. As they are purely a solubilised active ingredient in an oil or solvent with the presence of emulsifiers, they are simple to manufacture and relatively easy to stabilise. The presence of an oil also enhances the biological activity of the application, making them more efficacious in the field.
SC formulation, with an indication of what occurs upon dilution into the spray tank prior to application.
SC formulations, on the other hand, are suitable for insoluble active ingredients and those with higher melting points. Crucially, as water is the continuous phase, they are also typically safer and more convenient in use for the operator; there is an absence of dust, flammable liquids, and volatile organic compounds.
Built into each of these formulations alongside the active ingredient are formulation additives. Formulation additives, referred to as inert ingredients, are critical to provide the long-term stability to agrochemical products and their ability to mix effectively in the spray tank, making them suitable for [field spray] applications.
While the formulation type targeted is often dictated by the chemical characteristics of the active ingredient, the formulator has the ability to change every element of the spray quality characteristics and agrochemical delivery through selection of formulation additives. Changing both the formulation type and the additives within will habitually have a dramatic effect on the field efficacy of that application and subsequent yield and quality of the crop. Selecting the correct formulation additives is essential in creating a successful formulation, arguably making them as significant as the active ingredient itself.
How formulators learn to map the complex effects within formulations for improved crop protection is just one facet of today’s agriculture challenge.
Interested in learning more about how the formulation of agrochemicals plays its part in feeding the world? Visit: www.crodacropcare.com
More people are looking at their nutritional intake, not only to improve wellbeing but also reduce their environmental impact. With this, comes a move to include foods that are not traditionally cultivated or consumed in Europe.
Assessing whether this growing volume of so called ‘novel foods’ are safe for human consumption is the task of the European Food Safety Authority. The EFSA points out, ‘The notion of novel food is not new. Throughout history new types of food and food ingredients have found their way to Europe from all corners of the globe. Bananas, tomatoes, tropical fruit, maize, rice, a wide range of spices – all originally came to Europe as novel foods. Among the most recent arrivals are chia seeds, algae-based foods, baobab fruit and physalis.’
Under EU regulations any food not consumed ‘significantly’ prior to May 1997 is considered to be a ‘novel food’. The category covers new foods, food from new sources, new substances used in food as well as new ways and technologies for producing food. Examples include oils rich in omega-3 fatty acids from krill as a new source of food, phytosterols as a new substance, or nanotechnology as a new way of producing food.
Providing a final assessment on safety and efficacy of a novel food is a time consuming process. At the start of 2021 the EFSA gave its first completed assessment of a proposed insect-derived food product. The panel on Nutrition, Novel Foods and Food Allergens concluded that the novel food dried yellow meal worm (Tenebrio molitor larva) is safe for human consumption.
Dried yellow meal worm (Tenebrio molitor larva) is safe for human consumption, according to the EFSA.
Commenting in a press statement, as the opinion on insect novel food was released, Ermolaos Ververis, a chemist and food scientist at EFSA who coordinated the assessment said that evaluating the safety of insects for human consumption has its challenges. ‘Insects are complex organisms which makes characterising the composition of insect-derived products a challenge. Understanding their microbiology is paramount, considering also that the entire insect is consumed,’
Ververis added, ‘Formulations from insects may be high in protein, although the true protein levels can be overestimated when the substance chitin, a major component of insects’ exoskeleton, is present. Critically, many food allergies are linked to proteins so we assess whether the consumption of insects could trigger any allergic reactions. These can be caused by an individual’s sensitivity to insect proteins, cross-reactivity with other allergens or residual allergens from insect feed, e.g. gluten.’
EFSA research could lead to increased choice for consumers | Editorial credit: Raf Quintero / Shutterstock.com
The EFSA has an extensive list of novel foods to assess. These include dried crickets (Gryllodes sigillatus), olive leaf extract, and vitamin D2 mushroom powder. With the increasing desire to find alternatives to the many foods that we consume on a regular basis, particularly meat, it is likely that the EFSA will be busy for some time to come.
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.
A growing population is placing greater pressure on limited resources including land, oceans, water and energy. If agricultural production continues in its present form, water degradation, biodiversity loss and climate change will continue. As a result, people are adopting an increased interest in the environmental impact of food choice, choosing alternatives like insects.
This round-up explores examples of the various insect-based alternative foods.
According to data from Grand View Research, a US-based market research company, the global healthy snacks market is expected to reach $32.88 billion by 2025. Companies across Europe are developing healthy snack products based on insects, tapping into our desire for a variety of foods and tastes.
Eat Grub, established in 2013 and based in London UK, developed an insect snack made from house crickets, which are farmed in Europe. They are a sustainable, nutritious and tasty source of food, rich in protein. Research has indicated that insects are good for gut health due to their high chitin content. Chitinous fibre has been linked to increased levels of a metabolic enzyme associated with gut health.
A start-up Belgian beer company, Belgium Beetles Beer, described their drink as a real Belgium blond beer enriched with insect vitamins and proteins.
Upon ‘accidentally’ developing this product, they realised that the dry beetle powder offered a rich, light sweet, slightly bitter flavour.
A growing number of companies are now focusing their efforts on producing a product that looks and tastes like a traditional meat-based burger.
Bugfoundation’s burgers are based on buffalo worms, which are the larvae of the Alphitobius Diaperinus beetle. The company’s founders said that they decided to use buffalo worms because of their ‘slightly nutty flavour.’
The idea stemmed from a trip to Asia, where co-founder, Max Charmer came across fried crickets. His experience inspired him to bring these flavours to the west, hoping to please western tastes and comply with evolving European regulations.
Concerns regarding the livestock system have prompted novel inventions in the food space; insects, considered a source of protein, could outperform conventional meats to reduce environmental impacts.
So, will consumers soon be able to introduce insects to their everyday diets? Only time will tell.
How does climate change impact agriculture? Our Agrisciences group will be hosting an event on 6 March to look at just that!
Not only does climate change have a significant impact on agriculture, and the future of food security, but agricultural practices also directly contribute to climate change. Scientists, farmers and policy makers are coming together to find dynamic solutions to the problems caused by climate change in agriculture.
Agriculture provides food. Comprising of a variety of different farming systems, from crops to livestock, agriculture exists in almost every part of the world. Agriculture relies on knowing your geography – its soil properties, local pests and wildlife – but most importantly, the local climate. When these factors start to change, farming becomes a challenge.
We are already experiencing the effects of climate change, and turbulent or extreme weather is becoming more of the norm. As much as environmentalists can try to combat the development of these problems, agriscientists and farmers need to work together to overcome problems.
Consequences of climate change
One of the main consequences of climate change is a temperature increase. Even a slight temperature change can result in a significant effect on crop yields. Further to that, temperature change can result in drought, which affects the soil and plants alike, and lead to a change in pest numbers. An increase in atmospheric CO2 can also affect crops and livestock. Crops that thrive in higher CO2 levels will do better, but others may be negatively affected.
Not only will crop growth be affected directly by the weather, we could see a change in the diversity and number of pests. Image: Pixabay
Extreme weather events are also rapidly increasing in frequency. These include tornadoes, floods, heat waves, all of which can have quickly detrimental effect on farms. The 2018 British summer heat wave significantly affected crop farming in the UK.
As well as being affected by it, agriculture itself contributes to climate change. An estimated 10-20% of greenhouse gases are produced by agriculture, mainly from livestock.
Addressing the challenge
It is easy to consider that the impact of climate change on agriculture is something which can feel beyond our control. However, it is a dynamic challenge, and brings together scientists, academics, farmers, industry and policy makers, to overcome the negative impacts that a changing climate can have on agricultural systems.
Firstly, scientists can work to breed crops that are more resilient to these changes. They can identify genes for traits like heat and drought tolerance, pest resistance and stability under extreme conditions.
Solutions include plant breeding, GM crops, smart crop protection, policy changes and large collaborations across sectors. Image: Pixabay
Livestock farmers can help to curb climate change by introducing new diets that produce less overall methane. Other farmers can make shifts in their farming systems to more sustainable practices.
Policy makers can help with reducing the impact of climate change on agriculture. Not only by supporting environmental policies that potentially reduce the effects of climate change, they can also encourage scientific developments and relevant legislation relating to pest control, GM plants and other key areas.
Alterations to consumer practices can also reduce the impact of agriculture on climate change, and changes need to be made at all levels of the farming and supply chain.
How does climate change affect agriculture? Source: Syngenta
Overall, many parties need to collaborate to help to reduce the impact of agriculture on climate change, and help to overcome the problems that the future might hold, ensuring food security through a changing climate.
Figures on global data availability and growth are staggering. Data are expected to grow by an astounding factor of 300 between 2005 and 2020, and are predicted to reach 40 trillion bytes by 2020. This creates significant opportunities for data-based decision-making in industries such as agriculture.
Indeed, ongoing developments in precision agriculture and web-based apps can help the farmer to greatly enhance their efficiency, productivity and sustainability, and to prepare themselves for potentially catastrophic climatic events in real time.
On the other hand, farmers have traditionally relied on a more conventional approach for monitoring and improving their performance, namely, benchmarking. In a nutshell, benchmarking is about comparing one’s performance to that of their peers in terms of one or more performance indicators, typically expressed as ratios – i.e. output over input.
For instance, a dairy farmer may want to know how far their milk production per cow is from the top 10% of farms, or whether farms with a different management strategy than theirs (e.g. pasture-based farm vs. all-year housed system) could deliver higher milk yields. Farm benchmarking reports are standard practice in agricultural extension and consultancy.
However, these reports can be overly simplistic, because partial performance ratios cannot capture the multifaceted nature of agricultural sustainability, encompassing environmental (e.g. carbon footprints), social (e.g. labour use) and other indicators (e.g. animal health and welfare), in addition to economic and technical ones.
In April, EU Members States voted for a near complete ban of the use of neonicotinoid insecticides – an extension to restrictions in place since 2013. The ban, which currently includes a usage ban for crops such as maize, wheat, barley, and oats, will be extended to include others like sugar beet. Use in greenhouses will not be affected.
Some studies have argued that neonicotinoids contribute to declining honeybee populations, while many other scientists and farmers argue that there is no significant field data to support this.
In response to the recent ban, SCI’s Pest Management Science journal has made a number of related papers free to access to better inform on the pros and cons of neonicotinoids.
Like to know more about neonicotinoids? Click the links below…
Robin Blake and Len Copping discuss the recent political actions on the use of neonicotinoids in agriculture, and the UK’s hazard-based approach following field research unsupportive of an outright ban on the insecticides.
Conflicting evidence on the effects of neonicotinoids on the honeybee population has beekeepers confused and has led to the increase in the use of older insecticides, reports one beekeeper.
Following the 2013 EU partial ban on neonicotinoids, experts called for good field data to fill knowledge gaps after questioning of the validity of the original laboratory research. To encourage future debate, realistic field data is essential to discouraging studies using overdoses that are not of environmental relevance.
This paper describes the consequences of the ban on neonicotinoid seed treatments on pest management in oilseed rape, including serious crop losses from cabbage stem flea beetles and aphids that have developed resistance to other insecticides.
The Research Articles
Particle size is one of the most important properties affecting the driftability and behaviour of dust particles scraped from pesticide dressed seeds during sowing. Different species showed variable dust particle size distribution and all three techniques were not able to describe the real-size distribution accurately.
Aside from particle size, drift of scraped seed particles during sowing is mainly affected by two other physical properties – particle shape and envelope density. The impact of these abraded seed particles on the environment is highly dependable on their active ingredient content. In this study, the envelope density and chemical content of dust abraded from seeds was determined as a function of particle size for six seed species.
Substantial honey bee colony losses have occurred periodically in the last decades, but the drivers for these losses are not fully understood. Under field conditions, bee colonies are not adversely affected by a long‐lasting exposure to sublethal concentrations of thiacloprid – a popular neonicotinoid. No indications were found that field‐realistic and higher doses exerted a biologically significant effect on colony performance.
Currently one of the least digitised industries in the world, the agricultural sector is fast becoming a hub of innovation in robotics. One report suggests the agricultural robotics industry will be worth £8.5bn by 2027.
Feeding the increasing global population – set to hit 8bn by 2023 – is a major concern in the sector, with farmers already stretched to capacity with current technology.
With this said, the European Commission – via Horizon 2020 – has launched a programme and fund to drive research and innovation in the area. Developments in precision agriculture, which uses data and technology for a more controlled approach to farming management, has been particularly encouraging.
But similar to other labour-intensive industries, such as manufacturing, robots could be used to relieve workers in difficult conditions, and there are many projects close to commercialisation.
One such project is SWEEPER – a greenhouse harvesting tool that can detect when sweet peppers are ready to harvest through sensors. SWEEPER runs between the vines on a rail and uses GPS tracking to navigate through its environment.
Although focusing on sweet peppers for this research, the group say that the technology could be applied to other fruits and crops.
The EU-funded consortium in charge of the development of the SWEEPER robot is made up of six academic and industry partners from four countries: Belgium, Sweden, Israel and the Netherlands, where the research is based.
Greenhouses pose harsh working conditions during harvesting season, including excessive heat, humidity, and long hours.
The SWEEPER robot in action. Video: WUR Glastuinbouw
‘The reduction in the labour force has put major pressure on the competitiveness of the European greenhouse sector,’ said Jos Balendonck, project coordinator from Wageningen University & Research, the Netherlands.
‘We hope to develop the technology that will prevent greenhouse food production from migrating out of Europe due to the 40 % expected rise in labour costs over the coming decade.’
Currently testing the second version of the robot, the research group already envision adding improvements – from sensors that can detect vitamin content, sweetness levels and the sweet pepper’s expected shelf life to the ability to alert farmers when crop disease could hit their crops in advance.
A world first
Meanwhile, engineers at Harper Adams University in Shropshire, UK, and agriculture firm Precision Decisions have become the first group to harvest a crop completely autonomously.
The Hands Free Hectare project – funded by Innovate UK – modified existing farming machinery to incorporate open-source data that would allow the control systems to be located externally.
At the start of the season, an autonomous tractor sows the crops into the soil using GPS positioning, and sprays them periodically with pesticides throughout their growth. A separate rover takes soil samples to analyse nutrient content and to check pH levels are maintained.
When the crops begin to sprout from the ground a drone is used to monitor growth by taking images. Finally, a combine harvester controlled from outside of the field harvests the crops.
Kit Franklin, an Agricultural Engineering lecturer at the university, said: ‘As a team, we believe there is now no technological barrier to automated field agriculture. This project gives us the opportunity to prove this and change current public perception.’
Image: Hands Free Hectare
Despite innovation in the area, farmers have been slow to embrace the new technology, partially due to the lack of high quality data available that would allow more flexibility in the sector. Others, including the wider public, worry that development will lead to job losses in the industry.
However, scientists say the jobs will still be there but farmers and agricultural workers will use their skills to control the autonomous systems from behind the scenes instead.
‘Automation will facilitate a sustainable system where multiple smaller, lighter machines will enter the field, minimising the level of compaction,’ said Franklin.
‘These small autonomous machines will in turn facilitate high resolution precision farming, where different areas of the field, and possibly even individual plants can be treated separately, optimising and potentially reducing inputs being used in field agriculture.’
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.
On average, 10% of all crop production is lost annually to drought and extreme heat, with the situation getting worse year on year. Heat stress happens over short-time periods, but drought happens over longer timescales and is linked to drier soils. Maize and wheat are especially hard hit, with yields falling by up to 50% if drought hits.
On the High Plains, the largest US wheat-growing region, drought is a possibility every season. ‘Drought stress can be a key concern, especially in dry lands, but even in irrigated areas we can’t expect the same levels of water in future and farmers face restrictions,’ says Chris Souder at Monsanto.
So, this is not simply a developing world problem. Pedram Rowhani, University of Sussex, UK, found cereals in more technically developed agricultural systems of North America, Europe, and Australia suffered most from droughts. Yield losses due to drought were 19.9% in the US compared to almost no effect in Latin America.
Crop breeders in the past paid a great deal of attention to yield, but not enough to resilience to extreme events such as drought, Rowhani says, but this is changing. Growers increasingly want built-in drought resilience and plant scientists are looking for novel solutions. New, unconventional approaches based on novel insights from basic science might be necessary.
Hundreds of genes and proteins are involved in the complex trait of drought resistance. Plants avoid drought stress by shortening their life cycle with accelerated flowering, or cut down water loss by closing leaf pores called stomata. One approach by breeders is to target specific traits by crossing individual plants that perform best under drought conditions.
Stomata are found of the underside of leaves and are used for gas exchange. Image: Pixabay
‘About 97% of plant water loss occurs through the stomata. If you want to regulate the amount of water a plant uses, regulate the stomata,’ says Julie Gray, University of Sheffield, UK. Gray has been genetically tweaking wheat, barley, and rice plants so they have fewer of these pores.
She believes rising CO2 levels in the atmosphere means that they do not suffer from less carbon dioxide from opening their stomata. ‘CO2 levels have gone up 40% over the last 200 years. It’s quite possible they are producing more stomata than they need,’ says Gray.
Power plant in Tihange, Belgium. CO2emissions continue to increase. Image: Hullie@Wikimedia Commons
Gray reports that plants grown at 450ppm CO2 with reduced stomatal density, but increased stomatal size, had larger biomass and increased growth tolerance when water was limited. ‘Plants can operate with perhaps half as many stomata before you see significant effects on photosynthesis, so you can definitely reduce water loss this way,’ says Gray.
Root of the issue
At the other end of the plant plumbing system are roots. Susannah Tringe, Joint Genome Institute, UK, is seeking microbes that can gift stress-tolerance to their plant hosts. ‘The microbes associated with plants are likely to be just as important for plant growth and health as the microbiome of humans,’ says Tringe.
Though a lot of work has focused on finding the ‘magic microbe,’ Tringe believes whole communities will be necessary in real field conditions, whereas a single strain could be out-muscled by competitors.
Regular bouts of drought are leading to famine in developing countries. Video: Food and Agriculture Organization of the United Nations
Sugar and drought
‘Drought is probably the most widespread abiotic stress that limits food production worldwide. There is always need to improve drought tolerance,’ says Matthew Paul, Rothamsted Research Institute, UK.
‘Sucrose is produced in photosynthesis,’ Paul explains. ‘During drought conditions, plants will withhold sucrose from the grain, as a survival mechanism’. This can terminate reproductive structures and abort seed formation, even if drought is short-lived, greatly compromising yield.
A plant scientist studying rice plants. Image: IRRI Photos@Flickr
Rothamsted researchers have looked at modifying plants so sugar keeps flowing. ‘If you can get more sugar going to where you want it […] then this could improve yields and yield resilience,’ enthuses Paul. Field studies show that GM maize improved yields from 31 to 123% under severe drought, when compared with non-transgenic maize plants.
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.