The National Soil Monitoring Network NABO assesses and documents the soil quality at about 100 sites. The long-term monitoring facilitates an early detection of undesirable developments. Since 1985, this reference network has served the impact assessment in environmental protection. It focuses specifically on substance accumulation in the soil, soil compaction and soil biology.
Roughly half of the sites under long-term monitoring are used for intensive agriculture, including arable farming, vegetable farming, fruit farming and viticulture, or as intensively used grassland. One-fifth is located in extensively used areas such as pastures and alpine pastures, and about one-third in forests. In addition, two sites have been established in city parks.
The selected NABO sites represent a combination of land use, soil type, geology, altitude and other site properties that are typical of Switzerland. The monitored areas are neither marked nor closed off or otherwise protected so that the assessed conditions of agricultural or silvicultural use are as close to the actual situation as possible. Buried magnets allow an exact localisation of the 10 m x 10 m sites, guaranteeing the continuous sampling in the same areas.