Nuffield scholars have debated ways to overcome agriculture’s unsustainable dependence on artificial fertilisers, a subject which has become ever more prescient in the light of increasingly limited global resources, which have sparked dramatic price rises in fertilisers and fuels. Nuffield scholars Nik Johnson and Mark Tucker debated the situation at last week’s ‘Fertilisers for the Future’ industry conference.

Concluding a year of study and travel investigating the issues for their Nuffield scholarship awards, recycling phosphorus and adopting circular farming models were identified as solutions to the problems associated with dependence on finite fossil resources by the scholars. Concerns over the reliance on finite fuels and fertilisers, and the impact prices rises for these commodities are having on farmers’ margins, led to the European Parliament launching an investigation into input costs late last year.

MEP and rapporteur José Bové, who compiled a report on farm inputs for the Parliament, recommended increasing the resource efficiency of European farming and reducing its dependence on non-renewable resources by creating shorter supply chains and increasing agroecological production methods. He said his report, “Reiterates the need to replace this dependence on finite resources with sufficiently robust alternatives.” The report received almost unanimous backing in a vote in the European Parliament and was adopted in January this year.

Nuffield scholars discuss ‘closing the loop’ to ensure sustainable production

At the Fertilisers for the Future Conference,  Nik Johnson noted the complexity of the issues involved in measuring readily available phosphorus at farm level; he said that responsibility lay with farmers, consumers and government to address ‘closing the loop’ in the phosphorus nutrient cycle and being environmentally responsible.

“As things stand, it’s absorbed from the soil, enters into the human and animal food chain and then via the existing waste systems, the nutrient fails to be recovered,” Johnson stated, “But it’s not being recognised as a strategically important global commodity that is irreplaceable. Once this is accepted then the points at which phosphorus can be efficiently recovered and recycled can be identified.”

The scholar, himself an arable producer, was clear that farmers need to appreciate the finite resource bank of phosphorus in the soil, and suggested that, if they cannot commit economically to putting back that which is removed, then the crops should not be grown. He said, “In the case of phosphorus, there is a rotational timeline, and it can be done over a period of up to ten years.”

Turning attention to nitrogen fertiliser, Mark Tucker warned against relying too heavily on inorganic N; he urged growers to look to biodigestate, compost, livestock and green manures as effective alternatives. There has been an increasing amount of research on green manures and the beneficial effects such methods have on-farm conducted in Europe, whilst they can prove costly, green manures and other cover crops act as nitrogen fixers, reduce nitrate leaching and efficiently reincorporate other nutrients into land.

Whilst neither Nik nor Mark would predict the imminent demise of artificial fertiliser, the driver of fossil fuel scarcity was clearly recognised as a factor in raising input costs, whilst increased legislation is a further likely measure to mitigate environmental impacts.

The deadline for applicants seeking a Nuffield Scholarship in 2012 is 31st July.

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