Good food needs good soil. More money must be invested in soil science, says Tim Lang

For seven years, Defra has mulled over which indicators to use for soil. Last week, it published its soil strategy, eloquently launched by Defra chief scientist Bob Watson.

How the soil needs such champions! As a child I remember we all laughed at the Kenneth Williams character Arthur Fallowfield in the BBC radio show Beyond our Ken as he chimed "the answer lies in the soil" in a deep West Country accent. A witty put down, implying people bothered about soil are peasants, the past; we're modern, beyond that.

Last year the Royal Agricultural Society of England wrote an impassioned report about the dire state of UK soil science. Any country blessed with the great soil we've inherited should conserve it. Defra says we spend £5m on soil research. Ludicrously low! I say: put a 5p tax on growbags to fund a soil science renaissance. The Defra report says the condition of UK soil is not great but actionable by 2030. It needs to be nurtured like a baby.

Civilisation depends on soil. Managing its fertility over time requires complex social organisation. In the UK, industrialisation 200 years ago broke our management of the cycle whereby human, animal and plant waste could be reincorporated into the soil to build or retain fertility. All that potential fertility became pollution and reservoirs of disease. It wasn't until the sewers were engineered that cities became safer. As so often, it took crises for the rich (notably London's 1854 cholera and the 1858 Great Stink) to unlock purses and invest in prevention. The solution then was to harness rivers to dump human effluent out at sea, thus mixing fertility with dangerous contaminants.

In today's consumerist culture, we think fertility comes out of a bag, something to buy at garden centres or supermarkets. But artificial fertilisers are heavily oil dependent, so current farming methods are set to change pretty dramatically anyway. Our access to phosphates (from Morocco's Atlas Mountains) is both finite and subject to delicacies of geopolitics.

Every food company ought to have a soil science adviser. Good food requires good soil. We need to build that insight into our fumblings towards defining a sustainable diet and food system for the 21st century. Will anyone dare to put soil into their election manifestos or make it an indicator of corporate responsibility audits?

Tim Lang is professor of food policy at City University