170 A. Granstedt Agriculture, Ecosystems and Environment 80 2000 169–185
1. Introduction
Total annual inputs of nitrogen and phosphorus to the Baltic Sea are estimated to be 1 360 000 and 59 500 Mg,
respectively Stålnacke, 1996. Much of the pollution load is introduced into the Baltic Sea via rivers. An-
nual loads of nitrogen and phosphorus from the Baltic drainage area to the Baltic Sea in 1995 are estimated
at 761 000 and 37 500 tons, respectively HELCOM, 1998. Of the calculated load 34 originates in Estonia,
Latvia, Lithuania, Russia, 28 in Poland, 17 in Swe- den and 9 for Finland Table 1. However, per-capita
output levels of nitrogen are twice as high for Sweden and Finland compared with Poland. Levels of phospho-
rus and nitrogen in the Baltic are currently eight and four times higher, respectively, compared with what
they were in 1900 Enell, 1996. This increase is a re- sult of human activities around the Baltic Sea and in-
cludes point and diffuse sources. In Sweden it has been estimated that human activities account for 54 of the
annual input of nitrogen and 55 of the annual input of phosphorus to the Baltic Sea. Agreements to halve the
quantity of nutrients reaching the marine environment by 1995 were made within the Helsinki Commission
base year 1987 and at the North Sea ConferenceParis Commission base year 1985.
Agriculture has contributed substantially to an in- crease in nutrient leaching Jansson, 1997. One fifth
of the Baltic Sea drainage area is under cultivation. For Sweden, calculations indicate that agriculture is re-
sponsible for 42 of the anthropogenic nitrogen losses 69 030 Mg and 21 of the phosphorus 2590 Mg
Table 1 Loadings of nitrogen and phosphorus from the Baltic drainage area
to the Baltic Sea in 1995, by country HELCOM, 1998 Country
Nitrogen Phosphorus
Mg yr
− 1
of Total Mg yr
− 1
of Total Finland
66073 9
3561 9
Russia 84647
11 7108
19 Estonia
46468 6
1291 3
Latvia 91064
12 2184
6 Lithuania
36824 5
1405 4
Poland 214747
28 14208
38 Germany
21371 3
579 2
Denmark 68680
9 2598
7 Sweden
130872 17
4718 13
Total 760746
100 37652
100
losses from human activities. For Finland, the corre- sponding values were somewhat higher. From other
countries in Europe, too, similar values for the share of anthropogenic losses attributable to agriculture are
reported. In Germany, the proportions are estimated at about 44 and 28 of total nitrogen and phosphorus
inputs to surface waters Werner and Wodsak, 1995.
On the basis of official statistics it is possible to com- pare the increased use of artificial fertilizers and the
quantities of plant nutrients in food products Granst- edt, 1992a, 1995. From 1950 to 1980, the inputs of
nitrogen, phosphorus and potassium in the form of in- organic fertilizer strongly increased in relation to their
outputs in the form of agriculturally produced food- stuffs such as milk, meat and bread grain in Sweden
and Finland Fig. 1. Today, the input of nitrogen in artificial fertilizer to the agricultural systems is more
than three times higher than the output of nitrogen in the form of agricultural food products such as bread
grain, milk and meat. About 80 of the arable land in Sweden is used for producing animal fodder. This
was also true in 1950, but over the last 40 years the number of animal-producing farms has steadily de-
creased, while the number of animals per farm has in- creased. Meanwhile, the proportion of arable land used
for grain-based animal production has increased, while the ley proportion of arable land has declined from
about 45 to 38. Cattle population has been nearly halved, whereas pig population has almost doubled
SNV, 1994. In some counties in southern Sweden the concentration of animal production is particularly
marked i.e., in Blekinge, Halland and certain parts of Skåne. Thus, for example, about 5 of Swedish
farming enterprises account for 90 of the pork pro- duction SCB, 1998. Farms without animals currently
depend on artificial fertilizers to produce fodder for an- imals, which is then exported to the intensively man-
aged animal farms, resulting in excessive loads of plant nutrients there. A similar trend towards regional spe-
cialization in agriculture has been observed in Finland Granstedt, 1996, 1999 and in other parts of the Eu-
ropean Union Kleinhanss et al., 1997; Oomen et al., 1998.
Prior to the increase in the use of artificial fertilizer, which occurred around 1950 in Sweden and Finland,
crop production was based to a larger extent on effec- tive recycling through the use of manure from animals,
which were an integrated part of each farm. Between
A. Granstedt Agriculture, Ecosystems and Environment 80 2000 169–185 171
Fig. 1. Inputs of fertilizer nitrogen, phosphorus and potassium kg ha
− 1
per year and outputs of nitrogen, phosphorus and potassium kg ha
− 1
in the form of animal- and plant-based food products a in 1995 in Swedish agriculture and b in 1993 in Finnish agriculture. Data for the period 1940–1995 and 1940–1993 for Sweden and Finland, respectively.
1800 and 1950, i.e., before the large-scale introduc- tion of artificial fertilizers and pesticides, agriculture in
Sweden underwent a technical and biological revolu- tion aimed at meeting the increased need for food by the
Swedish population which had grown from ca. 2 mil- lion to 7 million during this period Granstedt, 1998.
Animal production was relatively equally distributed among farms, and the number of animals on each farm
was determined by the farm’s fodder-production ca- pacity. In addition, the manure produced on a given
farm was returned to the soil on the same farm. In other words, animal and crop production was integrated
on each farm. The agricultural system was also self- sufficient with regard to fodder for horses. The export
and losses of nitrogen were compensated through nitro- gen fixation in leys with clover and other nitrogen-fixing
crops in a crop rotation tailored to the needs and condi- tions on each farm. In this highly developed agricultural
system the importation of external resources was very low, and by reconstructing plant nutrient balances from
1951 it was shown that nitrogen losses were about 50 lower than compared with today SCB, 1997. In prin-
ciple, the same description is applicable to Finland, the difference being that the agricultural revolution came
about 50 years later there Granstedt, 1999, and also to other countries in Western Europe. Kjaergaard 1994
has described in detail how agricultural production in Denmark was increased substantially by the introduc-
tion of the legume clover as early as the 18th century.
The nutrient flows on various types of farms in dif- ferent regions of Sweden have already been determined
for 1990 Granstedt, 1995. The aims of this paper are i to determine the nutrient flows in different regions
of Sweden in 1995, ii to compare the situation in 1995 with that in 1990, iii to explain the strong de-
pendence on artificial fertilizers and the high losses of plant nutrients in agriculture today, and iv to describe
how, with the technological resources available today plant nutrients could be handled more effectively at
both the production and consumption levels, thereby minimizing losses of nitrogen and phosphorus to the
environment.
Although the results and discussion presented here mainly relate to the situation in Sweden, the general
conclusions reached are generally applicable to the whole Baltic Sea drainage area and also to agriculture
in other parts of Europe with excessive surpluses of ni- trogen and phosphorus. The ultimate aim is to create
the knowledge base needed for developing a strategy for changing Baltic agriculture systems so that losses of
nitrogen and phosphorus can be reduced by 50 hope- fully, only the first stage of a successive reduction in
the countries around the Baltic Sea.
2. Methods
