During the Second World War and afterwards, the Burrell family, as good patriots, did everything to their 3,500-acre estate at Knepp, West Sussex, that successive governments asked or ordered them to do. Along with thousands of other farmers, they ploughed up the traditional grasslands that provided pasture for their various livestock, along with a 350-acre garden by Humphry Repton, to make way for wheat. By 1939, after years of cheap imports from the USA and Russia, Britain was producing only a quarter of its own food. Suddenly, faced with a German blockade, the country needed as far as possible to feed itself. Britain avoided starvation by the skin of its teeth thanks to the heroic efforts of farmers and an army of eighty thousand Land Girls who worked up to a hundred hours per week.
After the war the Attlee government vowed that Britain would never be caught out again. They and subsequent governments decided that the way forward was to modernise. Messy and stroppy human labour was replaced by industrial chemistry and big machines, all as large as possible to achieve economies of scale. Hedges were grubbed up – 75,000 miles of them between 1939 and the 1990s – as little fields were merged to form prairies and small, complex farms were combined into big monocultural estates. The whole endeavour was boosted by the (oil-based) fertiliser and pesticide industries, which grew out of the munitions factories of the war. There’s a lot of overlap between the manufacture of fertilisers and explosives.