ORGANIC farming in the Middle Ages stripped the soil of nutrients, probably generated widespread malnutrition, and might well have contributed to the Black Death鈥檚 massive toll, according to a study presented at a British Ecological Society meeting in Sheffield this week.
The years just before the arrival of the plague in 14th-century England have always puzzled historians. In the previous century, the population had swelled to a peak of about 5 million, a level it would not reach again for some three centuries. But even before the devastation of the plague arrived, the number of people in the country had levelled off.
Ed Newman, an ecologist at the University of Bristol, wondered if the land was being overworked. So he contacted Paul Harvey, a retired professor of medieval history from the University of Durham who has studied the farming village of Cuxham in Oxfordshire. Cuxham鈥檚 landowner was the University of Oxford, which demanded detailed records of crop sowing and yield. These were recorded in Latin by a tenant farmer known as the reeve.
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Cuxham鈥檚 crops were rotated according to the three-field system. Each year, one field was kept fallow, one was sown with wheat and the last usually grew oats. From Harvey鈥檚 translation of the reeve鈥檚 records, Newman calculated a nutrient budget for the fields from 1320 to 134Q, nine years before the Black Death arrived, matching the removal of nutrient by crops against their return in the form of seeds, animal manure and by other natural processes. He concluded that nitrogen and potassium were probably in balance, but phosphorus was being removed from the soil far faster than it was returned. This may explain the declining wheat yields seen over the period, says Newman.
If other English villages were experiencing similar yield shortfalls, say the researchers, poor nutrition would have been a widespread problem, making people more susceptible to the coming epidemic. 鈥淭here are times and places when we believe whole civilisations collapsed and we don鈥檛 know why,鈥� says Newman. 鈥淗ere we can say that phosphorus is one thing they should have been worried about.鈥�
Harvey notes that Newman鈥檚 revelations are likely to dash modern enthusiasm for the simplicity of old-fashioned rural life. But as a professional historian, he is not surprised by the findings. 鈥淭he less you know, the more romantic history seems,鈥� he says. 鈥淚鈥檝e never met a historian yet who wanted to go back to the past.鈥�