The world faces a food security challenge to be able to produce more food sustainably. Previously on In Verba there have been contributions by Melanie Welham and Tim Benton discussing the complexities of food security and how to achieve it. Both note that research into a wide of technologies will be needed to address the challenge. Building on that, this blog post looks at research funded by the Royal Society which could contribute to food security.

Professor Martin Broadley, from the University of Nottingham, talks about the ‘Strengthening African capacity in soil geochemistry to inform agriculture and health policies’ project and the research on the importance of soil and micronutrients.

Dr Steven Spoel, from the University of Edinburgh, discusses the work he does as part of his University Research Fellowship on plant immunity.

Professor Martin Broadley – the importance of soil and micronutrients

Martin BroadlyRoyal Society: Tell us about your research

Martin Broadley: We look at plant mineral nutrition, which in general terms is the movement of mineral elements from the soil into plants and then into the food chain. We focus on plants as the entry point of minerals into the food chain. This is important against a backdrop of widespread mineral malnutrition, the need for sustainable intensification, and environmental degradation.

RS: What are you hoping to find out?

MB: Our research covers two general areas.

The first is looking at the mineral content of plants that enter the food chain. It is important for the health of people and animals that they get sufficient minerals from their diets. For example, about 2.5 billion people are deficient in zinc. To address this we can either add zinc to the fertiliser to make sure that plants that people at have enough zinc in them or breed new varieties of plants that have a higher zinc concentration.

The second is how we can use fewer inputs, like water and fertiliser, for crop production. This knowledge can be translated into applications to reduce pollution and the money wasted on unnecessary inputs.

As well as the plant science, we work with human and animal nutritionists and socio-economists to look at the costs and benefits of these types of approaches. This includes considering potential improvements to health. In the short term it might be more effective to add something to the fertiliser but over the longer term it might be more effective to look at breeding approaches for new kinds of plants that have, for example, higher mineral composition combined with good yields and resistance to disease or pests.

In the UK it is possible to get all the micro-nutrients that you need, but you have to eat a diverse diet. However, this might not always be possible for a number of reasons.  Also, there are potential constraints for some elements, such as selenium. Adequate dietary selenium is important for a healthy immune system.  For example, when the UK used to import most of its wheat from North America, where the soils are rich in plant-available selenium, most of the population would have had plenty of dietary selenium. Now that we grow most of our own wheat, which is a success in terms of production, many of us won’t eat sufficient selenium because our soils have less selenium. So unless people in the UK are eating a diverse diet they might be deficient in selenium. Food sources rich in selenium include offal and seafood.

We also work in subsistence-based food systems where more food is produced locally.  For example, we have been working for a number of years with colleagues in Malawi. The soils of Malawi are very different to those in the UK, they are much older and highly weathered.  There is very little plant-available selenium and limited quantities of other important nutrient elements, such as iodine, in these soils. Iodine is added to table-salt, so people in Malawi get most of their iodine that way. We are working with the Government in Malawi to track selenium and see if deficiency is affecting the population and if so what needs to be done to address it.  For example, it might be appropriate to use selenium fertilisers, as is practiced in several countries, including Finland.

RS: What are the implications of this?

MB: To use a breeding approach you must start with an understanding of the genetic variation and the interaction between the plant and the environment. I work with colleagues who are crossing wheat with wild relatives in order to improve resilience to heat, drought and salinity, and to have more nutritious grain.

Wheat and leafy vegetables have different abilities to accumulate different elements in their tissues, by identifying genes from more diverse types of non-domesticated plants or the molecular processes at work in grains and leaves of different species, we can selectively breed for beneficial traits into crops for cultivation.

For fertiliser we can improve the concentrations of minerals in the plants by understanding the interaction between the fertiliser and the crop. For both breeding and fertiliser research, we need to consider how these are deployed in the context of more sustainable production systems. For example, conservation agriculture seeks to minimise disturbance of soil which can help to improve soil fertility and moisture retention.

RS: Do you think that the way we produce food will change in the future?

MB: We routinely hear people giving dire predictions for food security, because of the rising population and climate change. However, I’m optimistic that research and innovation can help to support the sustainable intensification of crop production and wider food systems.

Food systems are immensely complex pathways from production to consumption. Research is important along this pathway, requiring contributions from both the natural and social sciences.

We are fortunate to have been awarded funding as part of a Royal Society-DFID Africa Capacity Building Initiative. This project is training PhD students in soil sciences in Malawi, Zambia and Zimbabwe. In addition to producing some excellent science to support regional agriculture and public health sectors, the wider initiative is seeking to minimise ‘brain drain’. Thus, by supporting tertiary education institutes in the region, we can increase capacity to offer opportunities to research the most pressing issues in food security.

Dr Steven Spoel– developing plant immunity

Dr Steven SpoelRoyal Society: Tell us about your research

Steven Spoel: My team and I work in in an area of research that looks to address food security. There is a rapidly growing world population which is expected to reach 9 billion in the next 30 years – when you translate that to food that needs to be produced per hectare of land, we are currently producing enough food for approximately four people per hectare and we will need to get this up to over six people per hectare.

This will need to be achieved against a backdrop of a decline in agricultural land as it comes under pressure from things like sprawling cities and soil degradation. We are interested in one way of addressing this that we think is quite important – reducing the loss of crops due to disease. Currently 10 – 40% of crops is lost to diseases caused by bacteria, fungi, viruses and insects. We are working on decreasing this loss by increasing disease resistance in crop plants by enhancing their own defence system.

We do fundamental research into the question of how plants defend themselves. In a process not that different to human vaccination, plants can also be immunised. After an initial attack and if the plant is able to fend off the disease, this can lead to lifelong protection against that diseases and often other diseases.

RS: What are you hoping to find out?

SS: We want to tap into this system to find a way to trigger immune system of plants.

We know that this process involves the plant hormone salicylic acid, which us humans are very familiar with. In 1500BC Egyptians would chew on white willow bark to treat inflammation, but it wasn’t until the 1900s that the active ingredient was identified as salicylic acid. These days the derivative is well known – it’s aspirin.

So plants use salicylic acid to fight diseases within themselves but how does it work?

We found that salicylic acid is directly perceived at the DNA of plant cells where all genetic information is stored. It activates a whole set of genes involved in the immune response and shuts down a whole set of genes involved in plant growth. We’re trying to understand the factors that perceive the salicylic acid and cause its action on genes. Once we understand this we can develop better strategies to boost the immune response, like creating compounds that mimic salicylic acid or by modifying the DNA to enhance salicylic acid perception or processing to get lifelong immunity.

RS: What are the implications of this?

SS: Eventually we would like to find new ways to make plants better able to resist disease. Reducing plant disease could prevent price hikes and economic losses. By improving the plant’s existing defence system, immune response can be turned on only when needed rather than being ‘on‘ all the time.

This is important as activation of the immune response diverts resources from growth. The sooner the infection is cleared the faster the plant can go back to growing, increasing the yield i.e. the fruits, vegetables or grains.

This could lead to a more sustainable approach by reducing the need for harmful fungicides and pesticides.

RS: Do you think that the way we produce food will change in the future?

SS: We have no choice but to change as our current methods simply won’t produce enough food, so finding new ways is absolutely vital. It is going to take a lot of work to do this and there is no silver bullet. It will require scientific research as well as social, legal and political work. We’re doing our bit by looking at plant disease but there will also need to be changes to agricultural practices to manage soils so they don’t degrade, agro-ecological solutions, and use of more crop varieties. There are still a lot of traits that we haven’t tapped into yet.

We should also be planting crops that are more suited to the ecosystem that they are in. Currently crops are being grown in areas that they are not ideally suited to, but another variety may be much more suitable.

Politically we also need changes. There should be a better balance between consideration of risks and benefits in looking at new technologies. At the moment there is often an emphasis on the risk rather than the benefit. This needs to be rebalanced.

  • Dan Danders

    “There is a rapidly growing world population which is expected to reach 9 billion in the next 30 years – when you translate that to food that needs to be produced per hectare of land, we are currently producing enough food for approximately four people per hectare and we will need to get this up to over six people per hectare.”

    There is an error in the framing of the problem as suggested here and elsewhere in this article. I highlight this error with the following question: what will an increase in food production accomplish in feeding the world’s population? And: what is the fundamental fuel for population increase? The latter I will answer – food production and access to other basic necessities of life fuel a growing population – if food is currently limiting, then increasing food production will drive an increase in human population.

    Logically, we know that the human population cannot grow indefinitely on a finite capacity for food production. There is a limit to human population size – the question we should be asking is what is a desirable level of human population size? I would propose it is one that will allow for the greatest balance of pleasurable human (and other animal) life. Will this be achieved through increasing crop production and allowing the population to reach 9 billion by 2030 (Do we stop at 9 billion)? This is open to debate, but I would expect that increasing food production will not promote the utilitarian’s goals. Assuming a larger population (e.g., 9 billion) existing under increased crop production but with unchanged circumstances of climate variability (and variation in crop production), a 10% variation in food production through time would translate into a greater number of humans facing starvation and malnourishment, concomitant conflicts among tribes, communities, and nations, and an increase in human suffering. Will an increase in crop production be met with a reduction in the variation in production? If not, we may see even more people facing misery than we do today. This is not even speaking of the toll that agricultural intensification can (but must not necessarily) take on other living animals and their well-being.

    We may project that the human population reaches 9 billion under current trends, but this does not suggest that our policies ought to promote this trend.

    If we can accept the premise that our actions should maximize pleasure on earth, then we can move forward with debate on how this is best achieved in our policy on human population growth, agriculture, and so on. I’m interested to hear input from others on the issues I have pointed out.

    • Stefano

      I believe this is a very interesting point. I wonder how you could determine or estimate the optimal range or threshold to limit population growth, so that further newborns would live a worse life and decrease life quality of everyone else (if I got your point right), i.e. humanity worsening its own conditions. What is the limit at which we could justify a fair life quality of a limited number of people against the freedom of giving birth and life?

      • Dan Danders

        That is certainly a difficult question, but it is certainly worthy of attention and debate. Would achieving the goal I have set out necessarily involve limiting freedoms? Some argue that education and empowerment of women to make their own life choices serve as a work around, as this is usually accompanied by a reduction in birth rate. Note, however, that the effect of a reduced birth rate is often offset (if only partially) by higher per-capita resource consumption and higher survival rate, which means there isn’t a 1:1 relationship between birth rate decline and population, yet generally speaking there is a positive return on for quality of human life. Nonetheless, people living in developed nations enjoy, on average, a relatively high quality of life and our populations tend to be on the decline when the effects of immigration from undeveloped nations is not accounted for. So there seems to be some evidence that conditions in developed nations (democratic governments, limited corruption, relatively high sense of security, access to education [including sex education]) promote the end goal. The underlying causes of our high quality of life in developed nations deserves careful analysis (for instance, how much of our quality of life gained is a direct result of exploitation of undeveloped nations and their people, resulting in a decline in their quality of life?). Putting these finer details aside, it is abundantly clear that the topic of human population limitation is taboo and remains untouched in our political spheres here in the West. Based on my judgement, this continues to be a major obstacle to the well-being of man, and the risks seem every bit on par with those discussed regularly by our politicians (terrorism, climate change, environmental degradation, poverty, access to clean drinking water etc.). Ironically, each of these appears inextricably linked to issues of population size and associated access to essentials for life.