Flying into Copenhagen or my local airport, Sturup, is a fascinating exercise in landscape history.  Away from urban areas the ground you look down on is divided into roughly evenly spaced farms, which form a semi-regular patchwork spread right across this southernmost tip of Sweden and on over the Danish islands.

It is tempting to read into these patterns a heart-warming lesson of cooperation and collaboration in early agriculture, but they are almost entirely the result of C18th and C19th land reforms, often imposed from above by an ruling class bent on higher profits.  They are the equivalent of – and were in fact inspired by – the Enclosure Acts in Britain and similar wholesale reforms on the European continent.  Instead of piecemeal working of thin strips scattered across a variety of communal fields, individual farmers and families were allocated a contiguous parcel of land equivalent in area and quality to their previous holdings.  Histories of the reforms tend to emphasise the rational, more productive agriculture that resulted, but the human cost and the social upheavals were vast.  I do not know of a Swedish poet to match John Clare in England in lamenting what was lost in the changes, but before and after maps make clear the immensity of the disruption and effort.  It is remarkable in today’s world of drawn-out planning permissions and zoned development to contemplate the audacity and determination of the reformers.

In Sweden the reforms included breaking up the old village centres and rebuilding many of the farmhouses out in the middle of their newly allocated land.  Ghost village squares can be found where all the farms simply evaporated, and it is quite common to find older parish churches in baffling isolation with no obvious community to attend them.  Another aspect of the Swedish enclosures was that there was no obligation to actually enclose the newly divided land.  To this English observer, the lack of hedges and mature boundary trees is one the most striking aspects of the Swedish agrarian landscape.  The difference is obvious even from the air.  Over Skåne the eye picks out block-like patterns of field shapes, whereas in a similar area of, say, the Welsh marches, it is the linear boundaries of the fields which dominate.  One thing however is common to both landscapes: the way that the most open fields often have a tree-ringed blob at their centre.


Slättåker, north of Lund

Maelor Saesneg, in the Welsh Marches

Further north in Sweden, such blobs are almost always an “åkerholm” or “field skerry”; a pile of stones laboriously cleared from the cultivated earth by hand and built up over the centuries as a monument to drudge and hard graft.  It is no accident that these features are largest and most common in the areas of Sweden that saw the greatest emigration to the USA.  Around Lund however, the farmland is the best in the country, and a closer look at the aerial views shows that most of the blobs are not heaps, but holes, usually filled with water.

Popularly, the holes are known as “duck ponds”, but their ubiquity suggests that either this is a misnomer, or earlier generations of Swedes had an unusually close and all-encompassing relationship with their web-footed friends.  Ducks and other aquatic fauna and flora do indeed love these handily placed mini-lakes, and today’s farmers are bribed to retain the holes as refuges for species whose normal habitat of marshes and meanders has been obliterated by drainage and canalisation.


An archetypical pit

The classic form has a squared-off end opposite a rounded one, and if the field is on an incline the rounded end is almost always on the upslope side.  If you are tempted to swim with the ducks you will find that the squared off end usually has a gradual slope into the water, while the rounded end is steep-sided.  Were it not for the green soup of algae and duckweed that thickens the water in any weather warm enough for skinny dipping, you might imagine the holes had be designed for swimming in.

Here, as is often the case in the utilitarian world of farming, form is a good guide to function.  The holes were not dug to provide a charming recreational water feature; in fact, they are usually sited so as to minimise water infill, which is why they turn so soupy in the summer.  Instead, they are the remnants of an early and extensive form of soil improvement called “marling”, in which chalky clays were dug out of the subsoil and mixed with the surface layer to improve its consistency and chemical balance.  The slope into the marl pit was there to allow a horse and cart to approach the steep workface.

In areas of easy waterborne transportation marl was mined on a large scale and distributed to farms some distance away, but the amount required is exceedingly bulky and heavy, and in most areas cartage fees could easily triple the basic price even for journeys as short as a few miles.  Where the subsoil was of the right type, it made sense simply to dig a hole in the middle of the field and thus to move the marl over the shortest possible distance. 


From Nordisk familjbok – a Swedish book on husbandry, 1913

The amount of marl dug out of a pit varied widely, which is not surprising considering variations in the clay’s composition and on the type and quality of soil on which it would be spread.  Figures range from a few tens of cartloads per acre up to several hundred, and either amount represents an almost unbelievable level of backbreaking toil.  It is no surprise that marling was an unpopular activity among those who actually had to do the work, not least because it usually took place in the summer between haymaking and harvest-time, just when custom demanded a period of rest leavened by dancing around the maypole and a relaxed attitude to public drunkeness.

Marling was practiced by the Romans, and has left sporadic traces in the European archaeological record for at least two thousand years.  Its great heyday was in the C18th and C19th when land reform, population growth and the early glimmerings of the science of soil chemistry combined to give purpose and intellectual respectability to an old country practice.  At best, marling could double the productivity of light acid soils, and because it was slow acting it needed only to be applied every ten to fifteen years.  A C16th saying put it: 

“a man doth sande for himself, lyme for his sonne, and marle for his graunde child”

However, marling was unpredictable: the principle effect of marl is to counter acidity and raise the soil pH, and until reliable chemical assays were available, marls could only be judged by crude measures such as their colour or consistency.  In the worst cases, marl could impoverish a soil by promoting the rapid breakdown and leaching of all its organic material, which led to the contradictory C16th saw:

“..ground enriched with chalke makes a fiche father and a beggarly sonne”

In Swedish there is a saying that is an almost literal translation:

“kalk skapar rika föräldrar men fattiga barn”

Once transport links improved, marling gave way to more frequent applications of lime from kiln-fired limestone or shell deposits, and later authors tend to be unusually dismissive about what had once been a widespread and productive agricultural practice.  Condescension to the supposed idiocy of the past is nothing new, but the tone in which marling is described as primitive and crude is more than usually supercilious.

Today, we have the scientific tools to understand marl as a fertiliser, but we rarely apply them because mechanisation and oil-based fertilisers have made the questions irrelevant.  Some marls especially rich in phosphate or potassium are still mined, but small-scale local use has completely disappeared.  The history of agricultural chemistry has generated many curios, and marling has joined others like the guano and coprolite fevers in leaving clues written in the landscape, but little in the memory.  The ducks at least seem grateful.