Structure: Undisturbed soils
Undisturbed soils and intact vegetation cover retain particles and thus prevent erosion. Mechanical processing of soil and removing of vegetation decreases the stability of soil aggregates and increases the washing away of soil particles. Main reasons for soil management in Finland are agriculture and forestry.
Most of the agricultural area is managed. The share of unprocessed fallow has been in recent years ca. 12%. Cultivated areas are commonly drained, about 70% was subsurface-drained, 20% had open ditches and 10% was undrained in 2013. Draining both increases and decreases the erosion. Draining decreases the moisture of the soil and thus prevents the fragmentation of soil particles. Smaller particles are washed away easier. But draining also speeds up the water current in the soil which increases the power of water to cause erosion. Also many agricultural procedures cause erosion such as tilling, insufficient buffer strips around ditches and other waterways, and lack of vegetation during spring and autumn floods.
Draining and soil preparation on felling areas are the main erosion inducing practices in forestry. Since the 1960s first-time draining has affected nearly 5 million hectares of forest land. This equals to one quarter of the total area of commercial forests mainly on mineral soils. (See graph on Nutrient retention > Structure)
Annual area under preparation was about 110 000 ha in 2012. Since 1950s nearly 5.5 million hectares of forest land has been managed. In the 2000s mounding has become the most common soil preparation method, in 2012 its share of all preparation was 60%. It is a lighter method than scarification and ploughing. Ploughing has been largely given up and the use of scarification and harrowing has decreased in recent years.
In the northernmost part of Finland reindeer grazing causes serious threat of erosion in lichen pastures. In the 1990s there were yet well regenerating lichen pastures in some northern districts but in the 2000s all of them were either regenerating slowly or heavily depleted. The number of reindeer rose in the 1970s which have led to overgrazing. Despite the extra wintertime feeding, the lichen pastures are deteriorating. (See Reindeer > Structure)
Utilised agricultural area. TIKE. Information Centre of the Ministry of Agriculture and Forestry.
Farmland management and irrigation. Agricultural Statistics.
Finnish Statistical Yearbooks of Forestry. Finnish Forest Research Institute.
- Updated (12.01.2015)