FRIBO: le reseau d' observation des sols agricoles fribourgeois.
1997
Julien P. | Morand D.
Between 1987 and 1991 250 observation sites were established, each site representing 400 hectares of agricultural land. 46 sites are located on high altitude summer pastures, 69 on permanent meadows at a lower altitude, and 135 on cultivated land. After five years of screening the main conclusions are as follows: the distribution of soil texture shows a gradient following the altitude. The heaviest clay-rich soils are located in the Prealps, whereas the light sandiest soils are more likely to be found northly in the region of the lakes; the organic matter contents can be considered as high in all types of soil used, especially in cultivated soils; half of the cultivated soils have important phosphorus stores, the soils which are rich to very rich in phosphorus being located in the cultivated lands of the north , whereas there is no specific region showing excessive potassium content; the cultivated soils are poor in magnesium and boron; a majority of the soils in the canton of Fribourg are acid, and liming is recommended for almost 60 % of the cultivated soils.
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