Properties and classification of soils of the Swedish long-term fertility experiments .3. Sites at Vastraby and S Ugglarp

The Vastraby soil (Kattarp) was classified as a fine, mixed, mesic Typic Endoaquoll according to the Soil Taxonomy and as a Haplic Phaeozem according to the FAO revised legend. The soil profile consisted of a very dark grey-coloured Ap-horizon and a subsoil with a calcium carbonate content (0.4-21.4%) increasing with depth. The textural composition of the Vastraby profile was found to be 24% clay, 20% silt (2-60 mu m) and 56% sand in the Ap-horizon and 55% clay, 42% silt (2-60 mu m) and 3% sand in the subsoil, on average. The bulk density was highest between 30 and 50 cm depth (1.70 kg dm(-3)), average values for 0-30 cm depth and the subsoil were 1.59 kg dm(-3) and 1.40 kg dm(-3), respectively. Assuming a groundwater table of 1 m, the amount of plant available water was 167 mm. Amounts of carbon and nitrogen in the Ap-horizon of the Vastraby soil were 73 t C ha(-1) and 5.6 t N ha(-1), respectively, while the subsoil to a depth of 1 m contained 42 t C ha(-1) and 5.4 t N ha(-1). The cation exchange capacity (CEC) amounted to 13.7 meg 100 g(-1) in the Ap-horizon. The main clay mineral found was illite, amounting to 35%. Kaolinite amounted to 7% of the clay fraction, chlorite to 1-2% and vermiculite increased from 3 to 15% with depth. Mixed layer minerals of illite/smectite type were present at 18% in the Ap-horizon and at 6% in the subsoil. S. Ugglarp soil was classified as a coarse-loamy, mixed, mesic Typic Hapludoll according to the Soil Taxonomy and as a Haplic Phaeozem according to the revised FAO legend. The soil profile consisted of a dark greyish brown-coloured Ap-horizon and a stony to very stony subsoil (15-30 vol%). The soil texture was silty loam with 8-15% clay throughout the profile. The bulk density increased with depth from 1.60 to 1.73 kg dm(-3). Carbon and nitrogen present in the Ap-horizon amounted to 74.4 t C ha(-1) and 7.75 t N ha(-1) and in the subsoil 12.2 t C ha(-1) and 1.95 t N ha(-1) were found. The CEC amounted to 11 meq 100 g(-1) in the Ap-horizon and ca 6.8 meg 100 g(-1) in the subsoil. The clay mineralogy was as follows: The content of illite increased from 28 to 37% within the profile. Smectite minerals varied between 18 and 24%, kaolinite amounted vermiculite to 5% and chlorite to 1% in the profile, on average.