Through our understanding of how plants secure their own nutritional requirements, we can provide new solutions for sustainable food production for the world’s growing population.
Plants must secure high levels of nitrogen, and in conventional agriculture nitrogen is added at high concentrations in the form of inorganic fertilisers. Artificial nitrogenous fertilisers can increase yield by as much as 50% and the global farming system, and hence our own food supply, is now dependent on them. We would face very severe food shortages if nitrogen fertilisers were to become unavailable.
However, their use comes with high economic and environmental costs. Farmers, especially in developing countries, spend a high proportion of their income on fertilisers that account for a significant proportion, sometimes the majority, of the costs of crop production. Fertiliser synthesis and application leads to high amounts of nitrous pollution in aquatic systems causing algal blooms and dead zones in shallow seas as well as nitrous pollution of the atmosphere causing poor air quality and significant greenhouse gas emissions.
But we cannot stop using fertilisers and meet a food security agenda; nor can we afford to keep using them and meet an environmental sustainability agenda.
Producing nitrogenous fertilisers requires lots of energy that currently comes from the burning of fossil fuels. It is anticipated that by 2050 2% of global energy will be used in fertiliser production [ref 1]; this represents the single largest energy input into intensive agriculture. This is unsustainable, and if the price of oil increases, so does the price of fertilisers, and so our food. Add to this the environmental costs of these fertilisers and it is clear that we need to find another way. I believe the answer lies in plants themselves – finding a biological and sustainable means of fertilising plants.
My research looks at leguminous plants, such as peas and beans. On the roots of these plants are small growths called nodules which are factories that supply all of the nitrogen the plant needs. Within the nodules are specialised bacteria that form a mutually beneficial relationship with the plant. The bacteria take nitrogen from the air and covert it into a form that the plant can use. In exchange the bacteria are supplied with sugars produced by the plant. It’s a beautiful and elegant system, and I’m interested in understanding the fundamental science behind this association.
This interaction involves signals between the bacteria and the plant. The signals trigger the plant to produce nodules to house the bacteria and also control the exchange of nutrients. Getting a complete understanding of the process will take a long time, but the driving force behind it is that if we can get a better understanding of the process we can look to transfer it into non-leguminous crops like wheat, rice or maize, the world’s three most cultivated crops. This would slash the amount of oil needed to grow them, and the amount of pollution caused by the fertilisers they currently need. However, transferring this process can only occur with the use of genetic modification (GM).
I see GM as a natural and biological solution to this huge problem. However, I know many people have a negative perception of GM. In this case I think the benefits are clear.
We are working very carefully and thoroughly to understand the process [ref 2,3], and then to predictably and safely transfer nitrogen fixation to crops. We know the effects of nitrogen fertiliser pollution on the environment, and we know the effect that burning huge amounts of fossil fuels has on our climate. But we do this anyway out of necessity to support current food supplies.
Balancing these very detrimental impacts against the perceived dangers of GM will, in my opinion, be the key to delivering the second, greener revolution in farming that we need to secure our food supply now and into the future.
- Is it possible to increase the sustainability of arable and ruminant agriculture by reducing inputs?
- Nodulation Signaling in Legumes Requires NSP2, a Member of the GRAS Family of Transcriptional Regulators
- Nodulation independent of rhizobia induced by a calcium-activated kinase lacking autoinhibition
About Dr Giles Oldroyd
Dr Giles Oldroyd leads the Plant Perception and Response to the Environment Programme at the John Innes Centre. He received a David Phillips Fellowship from the BBSRC and has received a number of awards for his research, including European Molecular Biology Organisation young investigator, European Research Council young investigator, Society of Experimental Biology President’s medal and a Royal Society Wolfson Research Merit award.
Dr Giles Oldroyd
John Innes Centre
Norwich Research Park
Tel: 01603 450000