One research question that motivates me is how did – and how might – Canadians stay warm and fed in a world without oil? Rural historians know plenty about the transition to fossil-fuel based fertilizers, field work, and modes of transportation, and we are learning more about the gradual adoption of coal heat and hydroelectricity in rural homes. But by focusing on new agricultural technology and its ecological fallout we often overlook, oversimplify, or romanticize the people who farmed with alternative forms. The use of “mussel mud” and other marine fertilizers on Atlantic Canadian farms is a case in point. In this post I explain how a unique organic fertilizer helped solve a local food shortage and why it was ultimately replaced by imported commercial fertilizers.
In the 19th and early 20th centuries, Prince Edward Island farmers extracted a local, organic fertilizer from the estuaries which dramatically increased food production for a period of up to 15 years per application. This seemingly sustainable alternative to imported fertilizers became known as “mussel mud.” In reality the mud consisted of mostly oyster shells, and as the shells broke down over time they released calcium carbonate into PEI’s highly acidic soil and increased its pH level. Digging the calcareous fertilizer through holes in the river ice and transporting it to nearby fields (all by horse power) became a PEI winter tradition, and a unique part of the province’s folklore.
Mussel mud digging is usually depicted in PEI books, articles, poetry, and museum websites as an example of a simpler time and a more sustainable form of agriculture. The farmers are portrayed as resourceful and self-sufficient, and their use of mussel mud is seen as a form of traditional knowledge that contributed to a golden age in the region’s agriculture. I think this requires qualification, but I too was fascinated by what this could tell us about Canadian food production in a system where inputs such as seed and fertilizers are produced locally. I was also fascinated by the unique connection farmers had with the coast. Not only were the estuaries a form of transportation and a source of seafood, waterfowl, and marsh hay, but they also contained rich fertilizers such as seaweed and mussel mud.
Hay grew poorly on PEI’s acidic soil – a major problem for an economy that demanded a large horse and ruminant population. The most important source of animal fodder in the early British resettlement period was marsh hay. This grew naturally in all of the Island’s salt marshes and on dyked wetland, but the amounts were small and the demand for beef and draft animals quickly outpaced the capacity of the marsh hay harvest.
PEI does not have any significant limestone deposits, and importing lime to increase soil alkalinity was expensive and unpopular. Coastal farmers have used crushed or burnt oyster shells as a lime substitute for centuries, but the amounts were small and required a fishery. As early as 1815, PEI farmers like George Meggison harvested “canoe loads of mussel shells for the land.” They also used seaweed and even live lobsters as manure, but in 1832 a surprisingly proactive conservation law prohibited PEI farmers from burning live oysters. Still, hundreds of acres of ancient shell beds provided a reservoir of seemingly free, limitless and long-lasting soil treatment right at the doorstep of PEI’s farmers.
The simple barrier that stood between farmers and these shell beds was the nature of the coast itself. For one half of the day sea waters covered the shell beds with strong tides and dangerous currents, and when the tide went out the beds were separated from shore by a buffer of impassible muck. As a result, crop yields languished in the acidic soil, livestock suffered through the long winter on a few hundred pounds of hay each, and observers like John MacGregor wondered “how many of the settlers raise enough to support their families.” In 1860, a Land Commission evaluated farms on a number of criteria, including distance from sea manure, and it noted that farmers found it “impossible to preserve land in this Island in a state of fertility, for any length of time, without the application of lime, or some other good substitute such as mussel mud, which but few can procure.”
In the 1850s and early 1860s, Island farms experienced a serious shortage in the amount of hay for livestock. Contemporary experts argued that the average cow required one ton of hay and plenty of straw to survive the winter. In the early 19th century the average hay-fed animal (horses, cattle, and sheep) survived on 700 pounds of hay, a small quantity of oats, and whatever they could forage through the snow, but by 1861 the amount of hay available per animal dropped precipitously by more than half.
According to David Weale, some innovative PEI resident developed a mechanical digger in the early 1860s that allowed operators to harvest the mud through holes in the ice and distribute it across the Island, first by sleigh and later by train. More than just an invention, mud digging required farmers to change their patterns of work. Much of their winter activity was thus converted from woodcutting to gathering sea manure in a dangerous, cold, and time-sensitive environment. By 1871, over 1,400 digging machines dotted the landscape, and ten townships along the Island’s central estuaries had coated over 15 percent of their cleared land with mud.
The mid 19th century yield problem was solved by an enormous outflow of time and capital, and the most dramatic effect of increasing soil pH was a significant increase in hay production. The hay crop doubled in the 1860s, and grew by 125% in the 1870s. By 1875, farmers like William Whitehead argued that without “mussel-mud we would starve on the farms-both man and beast. We could not grow hay enough to feed one horse.” Alexander Blue also testified that he “Couldn’t keep one horse if not for mud.” John McLeod claimed he was barely making a living from his farm before mud was introduced, and the soil treatment “increased the crop of hay 10 times.”
Through the adoption of mussel mud digging, PEI farmers effectively converted the cleared uplands into extensions of the salt marshes. With few external (i.e. “mainland”) inputs to the soil fertility cycle, farmers were able to maximize the productivity of mixed farming. However, no one in the 1870s would have considered this “traditional” farming; this was a new technology, and tradition meant hungrier animals and poorer farmers.
Almost immediately, this new form of soil treatment took on aspects that we commonly associate with industrial farming. Many, and probably most, of the diggers were commercial operators, selling loads of mud to farmers for 8-10 cents. The principles of supply and demand shaped the industry from there. Only the wealthiest and most established areas of the island had any significant amount of mud on their farms according to the 1871 Census of Prince Edward Island (not yet in the Dominion of Canada). Most of this mud was extracted from 3 or 4 central estuaries, and reports of exhausted shell beds appeared in smaller rivers as early as 1875. By 1893, the Federal Department of Fisheries intervened to identify and protect live oyster beds, and they drew lines in the ice that became flashpoints of confrontation in a predominately agricultural province. After two decades of attempting to manage farmers and fishers, Ottawa handed the mud problem over to the Province which began to dig mud at St. Peter’s bay and distribute it to farmers by rail. By the 1920s, Federal officials discouraged the use of sea manures, and farmers slowly began to adopt chemical fertilizers and imported limestone.
Andrew Hill Clark. Three Centuries and the Island: Historical Geography of Settlement and Agriculture in Prince Edward Island, Canada. Toronto: University of Toronto Press: 1959.
Matthew Hatvany. “‘Wedded to the Marshes’: Salt Marshes and Socio-Economic Differentiation in Early Prince Edward Island.” Acadiensis, XXX (2) (Spring 2001): 40-55.
Joshua D. MacFadyen, “Drawing Lines in the Ice: Regulating Mussel Mud Digging in the Southern Gulf of St. Lawrence,” in Claire Campbell and Robert Summerby-Murray eds.,Environmental Histories of Atlantic Canada (Fredericton: Acadiensis, 2012 [forthcoming]).
Colin MacIntyre, “The Environmental Pre-History of Prince Edward Island 1769-1970: A Reconnaissance in Force,” MA Thesis, University of Prince Edward Island, 2010.
David Weale. “The Shell-Mud Diggers of Prince Edward Island.” Canadian Papers in Rural History 2 (1980): 41-57