Who said organic farming was less productive?

By Stephan Kamrad

A while ago Joanna reported on a chemical free, organic pest control method that has a lot of advantages to conventionally used pesticides. Studies have shown that organic and comparable agriculture is more sustainable, as measured by indicators like species richness, soil fertility and nitrogen uptake. But even by most experts it is usually dismissed as a fantastical ideal that conflicts fundamentally with our need to feed the growing human population. This month, a new meta-study, published in the Proceedings of the Royal Society B, by scientists from the University of California reveals that the productivity gap between organic and conventional farming might be much smaller than widely believed.

Not so great after all? Credit www.CGPGrey.com

Not so great after all? Credit www.CGPGrey.com

The researchers analysed 115 studies covering over 30 countries and 50 crop species. Organic farming, defined by having no synthetic inputs, was found to be on average 19% (±4%) less productive than conventional farming. But interestingly, this obviously quite a drastic gap shrinks down to 9% (±4%) when the organic farmers use a polycrop system compared to a conventional monoculture. In polycrops, multiple species are grown together, e.g. in alternating rows, resulting in a greater biodiversity than conventional monocultures. This makes them less susceptible to disease and pests and certain combination of crops can act as biological pest repellants and natural fertilisers. In Joanna’s example in Kenya, maize was planted together with Desmodium (which repels the vicious Stemborer moth and also fixes atmospheric nitrogen). Another popular example found in British gardens is intercropping of tomatoes, onions and marigold.

The yield gap was also much smaller (8±5%) when organic farmers used crop rotations, i.e. planted a different crop in each growing season, a system which was once (in the Middle Ages) quite popular in Europe.

But where is the catch? If these techniques are so effective, why are they not used everywhere? More diverse systems are much more difficult to manage. Massive machinery cannot easily be used with companion crops and it is often advantageous for farmers to sell only one or a few crops in bulk. For small farmers in developing countries these techniques are easier to adapt but farmers often are not aware of the possibilities.

All this of course might be slightly too optimistic. After all, non-organic agriculture can also make use of intercropping (rare) or crop rotations (more common). In studies where conventional farming (i.e. the use of pesticides, weed-killers and synthetic fertilisers) was combined with polycropping or crop rotation, the yield gap returned to its original value or was even higher.

Interestingly, the yield gap also depends on what type of crop is under consideration. The yield ratio of organic to conventional farming is lowest for cereal crops, where a lot of effort has gone into the development of high intensity, large scale monocultures but often comes close to 1 for fruits and nuts, were less effort has been made in developing high output systems.

In our world, it is very hard to convince a farmer that he should tolerate a 9% or even 20% yield decrease for the prospect of a healthier agro-ecosystem, that is diverse, unpolluted and resilient to stress and disease. Diversification (be it over time as in crop rotations or over space as in polycrops) can raise organic farming yields and make it more competitive to conventional farming. With more investment it may be possible for the yield gap to be reduced even further.

Reference:

Ponisio LC, M’Gonigle LK, Mace KC, Palomino J, de Valpine P, Kremen C. (2015) Diversification practices reduce organic to conventional yield gap. Proc. R. Soc. B, 282:20141396. DIO: dx.doi.org/10.1098/rspb.2014.1396

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Vegan Mayonnaise: The Future of Food?

By Stephan Kamrad

Our diet, even today in the globalised age, is made up of surprisingly few plant species: Wheat, rice, potatoes and maize are the major carbohydrate sources for almost the entire planet. When it comes to livestock fodder, fruit and veg, the range is a bit broader but still limited to maybe a few hundred plant species and that although there are estimated to be over 400,000 plant species living on this planet!

So why is that? The reason for this is historical or at least traditional. Since the beginning of agricultural farming (~12,000 years ago) plants have been selected for productivity, palatability and resistance to pests, disease and environmental stresses. The plants we eat today are a reflection of our history, culture and tradition: the exploration of America marked a turning point in world history as well as European diets since it was the Spanish conquistadores who brought the potato plant back from their travels. Today in our globalised world, exotic fruits are flown around the planet so that we can enjoy kiwi, peaches, and strawberries, all year around. Still, rice and wheat remain the main food crops in Asia and Europe respectively as they have been for millennia.

Credit Jennifer Barry

Credit Jennifer Barry

But are we not missing out on the other 99.9% of plant species? Who can imagine what delicacies remain forever out in the wild because they have not been traditionally bred as crop plants or are simply unusual and scary to us? (Would you just eat a random berry you find in the wild?)

A company that has picked up on that is Hampton Creek, a food company based in San Francisco. They have developed a vegan mayonnaise substitute called Just Mayo. The key in developing this product was finding a substitute for the egg (yolk) traditionally used in mayonnaise. Just Mayo instead uses “Pea Proteins” as they declare it on their ingredients list. The company has screened, according to their press releases and adverts, many thousand plants for their properties and potential to replace eggs and continue to do so. “Pea” usually refers to the seeds of the Fabaceae family but what species and variety is actually used and how the protein is being extracted from the pea remains the companies secret. Known is that the product has only 65% of the saturated fatty acids of conventional mayonnaise and is cholesterol free.

“So what?” may you ask. After all organic food stores and supermarkets have been stocking plant-based alternatives for a long time, especially soy-based dairy substitutes and tofu. But the general conception is that vegan food is for hippies and leads to vitamin and protein deficiencies although it is in principle a lot more sustainable and more or just as healthy (with animal welfare being a whole other issue in our intensive meat industry). So in a way, Hampton Creek took and old idea and turned it into something more: looking at their ads and website, Just Mayo almost appears to be a superior lifestyle product with supreme nutritional value. In a funding campaign in February, the company raised 23 million USD, they were in Bill Gates’ The Future of Food feature and recruited Chris Jones (contestant of an American cooking reality show), Joshua Klein (CalTech graduate who previously worked on HIV treatment discovery), and Dan Zigmond (formerly Lead Data Scientist at Google Maps). Up to now, Just Mayo was mostly sold at up-town organic food stores, but their products are now available in Walmart (the world’s largest retailer) which will surely bring production volumes up and prices down.

Hampton Creek’s success has shown that there is a growing market for vegan products. Will this be the future of food? Are we learning to use the plants around us so that our diet becomes healthier and more sustainable without actually losing variety, money or taste?

Christianity and GMOs: An Interview with CICCU (2)

Nick Dinan talks to James Roberts from the Cambridge Inter-Collegiate Christian Union about the role of Genetically Modified Organisms in a Christian world view.

Read Part 1 of the interview here.

Nick Dinan: With regard to ‘not rushing things’, would it be right to frame your opinion as one that believes global issues such as global hunger are important, but if we want solutions we should take the slow route despite the urgency of these problems?

James Roberts: We could do a whole load of things other than GM crops to solve world hunger, such as better distributing the food we’ve got. There are perfectly adequate stopgap measures while we think about GM crops and evaluate them – whilst we make 100% sure that they’re all right. Doing that is a much better option than simply going ‘oh, GM crops are the answer here’ – it might not be.

ND: In May 2013 Monsanto sued, and won $85,000 from, a 75-year-old farmer for sowing the next generation seeds of the seeds that they had sold. Do you think there’s a major concern with the exploitation of GM crops by larger companies?

JR: You have situations where whole groups of people are dependent on the seeds of a genetically modified crop. Seeds are marked up in price and aren’t affordable, and the farmers end up in a worse position than before. We need to consider how to ensure that this technology isn’t manipulated simply for profit by big business. We need to think about how to regulate that.

ND: I assume that most people in the Christian community would agree with this?

JR: The Christian community I can say generally agrees on this, and I think this applies to a wider range of issues than GM crops as well; the issue of justice is one that hopefully would be close to home.

ND: So the ‘Christian value’ would be to help people, but in a way that conforms to what you’re taught in the Bible?

JR: I would say that the Christian moral standpoint should come from the Bible. That has to be our first authority on everything. So how we think through these issues should ultimately derive its reasoning back from the Bible.

ND: And finally – you said that your opinion came from studying biology in school, so it obviously was the result of some educational exposure. Do you think that members of the Christian community could do a lot more in educating themselves on the biology of GM crops before making an opinion?

JR: We need to make decisions based on the facts, based on what we’re presented with through the education system. I don’t think that’s our responsibility; the government has to give us the facts. Then, what we do with them has to conform with our reading of scripture. If someone’s honest view is that tampering with God’s creation is morally wrong, then I think no matter the biology that’s the conclusion they have to come to. However, if someone from scripture like myself has come to the conclusion that tampering with God’s work is not the problem, then the next step down in your reasoning has to be whether or not the biology says it’s the right thing to be doing. Have we got a full enough grasp of how it works to be able to do it in a way that isn’t going to cause damage? Can we do it as responsible stewards? If it’s yes to that, then I think the conclusion that we should come to is ‘yes, it’s fine’.

Christianity and GMOs: An Interview with CICCU

By Nick Dinan

As a scientist and atheist, a perspective of genetically modified (GM) crops rooted in religion is one that is naturally foreign to me. I sat down with James Roberts, representing the Cambridge Inter-Collegiate Christian Union (CICCU), to explore the moral conflicts of GM foods – are they rebelling against scripture or are they acceptable within the standards of the Bible?

Nick Dinan: What are your personal views on GM crops? 

James Roberts: Personally, I think they’re a bad idea, but not from a Christian perspective. I don’t think that the technology is good enough to ensure that something bad doesn’t happen.

ND: Do you think that your particular views are representative of the Christian church, or at least the Christian Society within Cambridge?

JR: I think there’s a broad spectrum of viewpoints. There’ll certainly be some people who are against it, because quite stereotypically you’re ‘playing God’. However I don’t particularly think it’s an issue. The Bible in Genesis calls for us to be stewards of the world, care for God’s creation and to look after it under his ultimate rule. So I don’t think GM crops are particularly different from what we’ve been doing for thousands of years through selective breeding – it’s just skipping out a couple of steps.

ND: You point out that we help the plants skip a couple of steps ahead. Technology is progressing to the stage where we may take a few steps further than that. Where do you think the line will be drawn for GM crops to still fall under God’s natural order of things?

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Credit leyink

JR: It’s a very grey area. It depends what you’re trying to do and what you’re trying to achieve. If there is some kind of beneficial goal at the end then I think that probably justifies what you’re doing. For example, if you’re going to end up with a plant that produces something beneficial, you can probably justify it. However, if you’re just fiddling around with genes out of curiosity then that’s not such a great thing.

ND: Developing these techniques to eventually reach a positive goal is often the result of ‘fiddling around’ without knowledge of what future benefits may be. In that respect, how would you distinguish between fiddling around and aiming towards a positive goal?

JR: It comes down to your motivations – are you being a good steward? Are you keeping in mind the risks and what could potentially go wrong? Are you taking precautions? Basically, we want good scientific practice. Thinking through those things is what differentiates between carelessness and actually doing something that can benefit the scientific community and humanity.

ND: From your own perspective, do you believe that someone who disagrees with GM foods for religious reasons should then logically be against gene therapy in humans?

JR: I think the underlying question is that there’s a difference between humanity and the rest of creation; humanity is made under God’s image as a special creation. However gene therapy and GM crops seems to me almost as one in the same thing, you just need to be more careful with humans. I don’t think that if you’ve decided to be against GM crops you could say that gene therapy is okay, but I’d add a pinch of salt to that as I don’t know the ins and outs of gene therapy.

ND: So in terms of a being a steward to these resources, surely we should be doing the best to help those around us. For example, golden rice provides a precursor to vitamin A, and vitamin A deficiency is something that kills 675,000 children a year – GM crops can really help people. Is there a moral dichotomy between tampering with God’s work and helping these people?

JR: So I think being a good steward involves not only making the best use of resources, but also being responsible with what we’re using. If the risks involved in creating golden rice were too great, then no matter what the potential gain of the end goal is, it’s not right. The ends don’t justify the means if your means are full of hazards. But I don’t think that you’re tampering with God’s creation if you’re manipulating crops.

ND: I know that you’re very much focused on the risks of GM food, but putting yourself in the shoes of a someone who is against GM crops from a Christian moral context, is there a conflict between the potential gains of GM crops and the fact that GM crops could be a moral injustice?

JR: I think if their conscience is telling them that ‘to do this would be to go against God’s rule’, then for them to sanction it is wrong no matter what the potential gain is. If they see it as rebelling against God, then it is not something they should do.

ND: I want to return to your concerns that you mentioned in your first answer about the risks of accidentally putting toxins in. A wheat crop undergoing testing in the UK has been engineered for Aphid resistance using naturally occurring, non-toxic proteins existing in the food chain. Toxins are therefore highly regulated and the risk is low. Do you think that despite the chance of toxicity being very small, we shouldn’t support GM foods?

JR: I think it’s something you’d need to think very carefully through. You need to think about the long term as you could have something that could build up in the ecosystem and be toxic at higher concentrations. It’s just about caution, really. I think we should be against GM crops as a whole as it’s just not something we should rush into. We need to make sure we’ve thought of all the hazards and risks. If it’s fine, then why not, but we always need to bear in mind that we don’t think about these things properly a lot of the time. The scientific process is riddled with potential biases and errors and things that we don’t spot like thalidomide and that kind of thing. We often have an under appreciation of the hazards involved

Part 2 of this interview will appear on the 4th of February 

Super-domestication: making plants work for us

by Leanne Massie

Super-domestication is a relatively new term to describe plants that we have modified to extremes to fit our own needs. For example, crops that have huge yields with minimal negative effects on the environment could be called super-domesticates.

These crops are still works in progress though; the most notable super-domesticate-to-be is “C4 rice”. Rice is naturally a C3 plant, which means it uses a less efficient method to capture carbon from the atmosphere. Some plants that are adapted to hot, dry conditions have evolved a different carbon capture mechanism called C4 photosynthesis, which allows them to take up more carbon dioxide and lose less water in the process, a sort of supercharged version of photosynthesis. If C4 photosynthesis could be introduced into rice the benefits are staggeringly huge. Yields would be increased while at the same time water use would go down. In a world where water shortages are starting to affect everyone and where rice already provides more than one fifth of the total calories consumed worldwide, a C4 variety of rice would go a long way to ending world hunger.

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Credit: Dalgial

This isn’t an easy process though; introducing C4 into a C3 plant is like trying to compare pricing at a supermarket, extremely difficult!. It can be done but takes huge amounts of effort and determination.  But fortunately, C4 photosynthesis has evolved more than 50 times in nature so with the right tools it is very feasible. The C4 Rice Consortium, a foundation that has more than 600 scientists worldwide, has been working on introducing C4 photosynthesis into rice since 2008 and the researchers have collectively published over 400 papers relating to C4 rice since. The scientists are well on their way to making rice into a super-domesticate.

However, this is only rice. Wheat, corn, potatoes, tomatoes, and peas are just some of the other crops that are also being studied to make them work harder for us. Imagine the possibilities that super-domestication could bring if all our crops were supercharged to their full potential.

For more information, see:

C4 Rice Project. http://c4rice.irri.org

D.A. Vaughan, E. Balazs, J. S. Heslop-Harrison (2007) From Crop Domestication to Super-domestication. Annals of Botany 100: 893-901

The little alga that could: Algal photosynthesis and its potential for incorporation into crops

By Charlie Whittaker

Algae are pretty cool. And when I say pretty cool, I mean ridiculously cool. They’re involved in everything from potential biofuel synthesis to novel metabolic pathway generation, but they’re also pretty special because of the unique way in which they fix carbon and generate new biomass.

Algae

Image of the algae Scenedesmus quadricauda. The pyrenoid is visible in the middle of each of the cells as the distinct circular object.

The main site of carbon fixation (the way plants and most other photosynthetic organisms, including algae, incorporate carbon dioxide to produce molecules that will eventually become new biomass) is at an enzyme called Ribulose Bisphosphate Carboxylase Oxygenase, or Rubisco for short. Rubisco catalyses the addition of CO2 to Ribulose Bisphosphate, producing a precursor that will eventually go on to generate glucose, sucrose, cellulose, and other sugars. These in turn can be respired to generate chemical energy for the cell or be polymerised to make the macromolecules constituting new algal biomass. However, as well as having the capability to interact with CO2, Rubisco can also catalyse another pathway, by which O2 is added instead. Known as the oxygenation reaction, this results in a net loss of carbon, which is highly problematic for the plant.

Algae tend to be aquatic, and this presents a number of challenges with regards to getting sufficient CO2 to supply and meet the cell’s demand. Diffusion is very slow in water, and thus it takes a long time for CO2 to enter the cell. As well as this, CO2 equilibrates with water to form bicarbonate   (HCO3) on a pH dependent basis. The pH of seawater is such that CO2 is mainly available in the form of bicarbonate, potentially representing another barrier to CO2 uptake.

In response to the challenges associated with living in an aqueous environment, algae employ what is known as a biophysical carbon concentrating mechanism to ensure CO2 supply to Rubisco, and hence carbon fixation, is not compromised. They possess a cellular microcompartment within their chloroplast called the pyrenoid, where all of the Rubisco contained within the cell is stored. In most photosynthetic organisms, plants included, Rubisco is spread throughout the entire chloroplast. By localising Rubisco to this single area, CO2 extracted from the surrounding environment can be concentrated in a single, small area.

Chlamydomonas

Stylised cross section of a Chlamydomonas reinhardtii cell showing the pyrenoid and other subcellular components.

As well as this dense aggregation of Rubisco, the carbon concentrating mechanism involves a number of other proteins. CO2 is taken up from the extracellular environment into the algal cell in the form of bicarbonate (HCO3). From there it is shuttled via a series of transporters into the chloroplast, whereupon it gets converted back to CO2 in the thylakoids by an enzyme called carbonic anhydrase, and is then subsequently delivered to the pyrenoid. The idea behind this is that in doing so, the algal cell is able to effectively exclude O2 from the pyrenoid, due to the specific nature of this CO2 delivery, and also ensure a continuous supply of CO2 to Rubisco, given the ubiquity of HCO3 in seawater. This increases the efficiency of photosynthesis, and maximises CO2 fixation.

At the moment, efforts are being made to engineer some aspects of this system into higher plants. The idea behind this is if something resembling a pyrenoid was developed in crop plants, they would be able to better exclude oxygen from the site of carbon fixation (i.e. Rubisco) and increase photosynthetic efficiency. This would translate to substantially increased yields, which is important for food security the world over, particularly in the face of increasing climactic variability and increasing global temperatures, as well as a rapidly increasing population. With more mouths to feed globally, and no concomitant increase in farmable land (if anything, a decrease due to changing weather patterns) increasing yields of key crop species such as rice, maize, cassava and millet represents an important objective for ensuring supply can meet demand globally, as well as making sure that small scale farmholders have the necessary tolerance built into their yields to allow for extreme climactic fluctuations, something that will become increasingly common in the face of climate change and global warming.