A team led by Dr Duncan Cameron and Dr Jurriaan Ton believes that UK farming’s inevitable future will be a combination of genetically modified crops on organic farms fertilized by human waste. Analysis by the University of Sheffield team has found that the UK’s available soil has just 100 seasons of nutrients left in it.
Dr Duncan Cameron from the University of Sheffield said: “Safeguarding food security for future generations is one of the biggest challenges for the 21st century. In a time of rapid environmental change we need new ways to intensify sustainable production and protect food crops. This isn’t optional. Like it or not, the sh*t is going to hit the fan.”
The challenges of modern day agriculture are numerous: climate change, soil degradation, water shortages and growing demand. Phosphorous and nitrogen are limiting nutrients, essential to the growing process and both are found in human waste which the scientists believe could be used more efficiently. People produce an average of 1.5 tonnes of faeces and urine each year. The University of Sheffield team believe that this will provide 20 kg of elemental PNK fertilizer, enough to grow 200 kg of cereal.
The work is part of Project Sunshine, an initiative led by the Faculty of Science at the University of Sheffield that aims to unite scientists working in both pure and applied sciences to harness the power of the Sun and tackle the challenges of meeting the food and energy needs of the world's population in the context of an uncertain climate and global environment change.
The careful cross breeding of plant characteristics during the so-called “green revolution” between the 1940s and the 1970s resulted in highly productive crops and, according to estimates, saved more than a billion people from starvation. The process, though, has not been not without consequence. Plants today are heavily reliant on fertilizers and many have lost the important natural traits that enable them to interact with beneficial bacteria and fungi in the soil.
Today scientists are capable of identifying the exact genes that were lost during breeding programmes. By applying modern day GM technologies, these ‘lost genes’ can be put back and crops returned to their more communicative nature.
The University of Sheffield’s scientists say a sustainable farming future also has to be more reliant on organic farming that relies heavily on the natural breakdown of organic matter to replace nutrients taken from the soil by previous crops.
Human waste is already deployed in some developing countries, driven by water shortages and escalating fertilizer costs. All health risks can be eliminated from human excrement by proper composting.
Dr Duncan Cameron, from the University of Sheffield, added: “We need to break the cycle that has led to many crops requiring the agricultural equivalent of spoon feeding, with chemical fertilisers and industrial irrigation. Whilst seemingly efficient, we are mollycoddling nature and this will lead to substantial yield losses due to pests and diseases.”
Global crop losses by diseases and pests have been estimated to amount up to one third of its potential production, whereas abiotic stresses cause further substantial crop losses annually.
The University of Sheffield team is developing new methods that enable these functions to be restored in combination with more sustainable management of agricultural land.