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Cambridge University Science Magazine
The UK’s industrialised farming sector produces a little over 60% of our food with just 1.5% of the working population. A key characteristic of this system is a reliance on intensive monocropping, whereby the same highly profitable, high-yield crop is grown on the same land year after year. However, the so-called Green Revolution of the 1960-70s, culminating in these practices today, was a decisive shift away from sustainability after a millennia-old evolution of crop rotations in the UK. To tackle today’s threats of ecological degradation, we now need to appreciate these sustainable farming practices of old once more.

New growth

The first domestication of crops originated from the Neolithic and Bronze Ages, approximately 6,000 years ago. However, although certainly adopted by countless societies and indigenous peoples already, the systematic application of crop rotation practices in the UK only appeared two millennia ago with Roman society. This prescribed a three-field crop rotation system: one fallow year during which livestock was to be secured overnight, a winter sowing year of wheat or rye corn, and finally a summer crop of oat or barley. The growth of varied species, the fallow recovery year, and livestock returning nutrients to the land together provided maintenance of soil health and pest control. These attributes meant that it endured far beyond the Roman Empire, and, despite its simplicity, this system is still practised in parts of the UK today.

However, shifting socio-political views would eventually alter these long-held farming regimes. From the early 17th century, Enclosure Acts redistributed land ownership and weakened tenant farmers’ rights. This included limiting the movement of livestock onto fallow land, destabilising a critical pillar of the three-field system. Positively, however, bolstered profit incentives led to reclamation of unused land and the development of innovative methods such as the Norfolk four-course rotation in the 18th century, underpinning the so-called British Agricultural Revolution. This latter improvement to crop rotations was massively successful. A clover ley year was typically used to restore soil nitrogen while also allowing livestock to graze, which strengthened soil fertility and sustainability.

At this point, an exciting era of experimentation in crop variety and rotation design began. Some rotation practices entailed cycles spanning anywhere from five to eight years, with the growing appreciation of the benefits that certain crop types afford soil health in the long run. For example, root vegetable crops allow efficient weeding of the fields at the same time as production of an energy-rich food. Certain crops allow simultaneous grazing of livestock and thus increased provision of natural fertiliser to arable land. Overall, the returns in productivity were significant and helped fuel a sharp increase in the UK population during this time.

Despite its strengthening up to the 1900s, industrialisation and globalisation nonetheless began to threaten UK agriculture. The advent of refrigeration allowed for lengthened supply chains, and this, in combination with increased wider European productivity, would lead to an increase in imported competition. Along with the acute pressures of the World Wars, the long-term prospects for our food supply system were uncertain. However, these conflicts also emphasised the importance of self-sufficiency. In response, the modern era of agriculture began to take shape. This Green Revolution of the 60s and 70s fuelled an impressive recovery from WWII and led us directly to where we stand today — for better or for worse.

Forgetting our roots

Most crucial to this fresh phase of UK agriculture was the new availability of cheap artificial fertilisers and pesticides that replaced the need for natural soil recovery through crop rotations. In an effort to prevent food shortages reminiscent of WWII, investment into new technologies and mass farming techniques of monocropping quickly soared. Old practices of crop rotation were soon a distant memory. Global trade pressures further incentivised regional specialisation in production to achieve economies of scale and outgrow competition.

Beyond rapid growth, a recent research paper by Dr George Cusworth and colleagues at the University of Oxford describes how this revolution became ‘locked-in’: the aggregated social, political, and economic factors of the time disadvantaged other farming regimes in a self-reinforcing manner. For example, popular new crop strains bred for modern monocropped fields and cheapening requisite materials only made the industry more profitable. This further engrained the new methods with little thought given to the long-term consequences.

The effects are only now being fully realised, as reported recently by the UK Government and the Intergovernmental Panel on Climate Change. Indeed, Cusworth and colleagues identify four primary consequences: biodiversity loss, soil degradation, greenhouse gases, and water nitrification. In 2017, then-environment secretary Michael Gove reported that the UK is around 40 years away from ‘the fundamental eradication of soil fertility’, largely a result of taking so much from the land while giving nothing but damaging chemicals in return.

A new leaf

Could huge system change happen once again? On a practical level, our knowledge of the past combined with modern-day scientific research means we understand the principles underlying a sustainable food production system better than before. However, as for much of modern life, the challenges we face are more political than technological. We understand the benefits that diversity in our soils brings to our environment, but only by truly valuing this both in thought and practice will we move forward.

In fact, social, political, and environmental pressures are slowly being felt. In their recent paper, Cusworth carries out interviews across the farming sector in an attempt to document this and in doing so to exemplify how we can collectively and individually advocate progress. They propose three key factors shaping our current agricultural landscape: government policy and subsidies; research and appreciation of the impacts of different practices; and consumer demand. For example, the need for modern regulations to fill the space left by Brexit has encouraged the introduction of new Environmental Land Management Schemes currently being trialled. Interviewed farmers were enthusiastic about such schemes potentially allowing more sustainable yet still profitable farming. They further expounded the benefits of crop rotations and increased legume crop inclusion in particular. UK consumer demand for plant-based products is also skyrocketing, growing by 40% in 2019 alone. With this, the viability of cultivating more diverse leguminous crops is improving steadily. As remarked by one interviewee: ‘You know, these vegans want something to eat, so the market’s there!’.

Thus, knowledge of our agricultural history, combined with modern pressures even at the level of individual choices, is propagating a movement back towards the higher agricultural diversity and crop rotations from years past. Importantly, these seem set only to accelerate. Voting, spreading knowledge about these issues, and individual actions all let us enact change — and it is a change that our soils urgently need.

This piece drew inspiration and key information from a recent publication by Cusworth et al. (2021, Journal of Rural Studies) and from Knox et al. (2011, Journal of Sustainable Agriculture).

Tim Birkle is a third-year PhD student in biochemistry at Christ’s College. Artwork by Pauline Kerekes.