Ultuna Long-term Soil Organic Matter Experiment, Sweden

Samples were taken when starting the experiment. Sampling depth: 0-20 cm. Soil samples are kept; unfortunately some were destroyed.

Details of soil sampling method: Soil sampling: 0-20 cm. 5 subsamples. Every second year. c) Soil measurements made and frequency Total carbon: Every second year Method of measuring total carbon: 1956-1983: Wet combustion (Jansson & Valdman, 1961). 1984->: Dry combustion (Strohlein Instruments) Biomass carbon: 1988,1989, 1990 Method of measuring biomass carbon: Fumigation-incubation; Fumigation-extraction; ATP. (Witter et al 1993) Carbon dioxide evolution: 1988, 1989, 1990 Method of measuring carbon dioxide evolution: Fumigation.

Witter et al 1993 Total nitrogen: Every second year Method of measuring total nitrogen: Kjeldahl Biomass nitrogen: 1988, 1989, 1990 Method of measuring biomass nitrogen: Funigation-incubation; Funigation-extraction. d) Details of the meteorological station Nearest meteorological station to the site: Ultuna which is .2 km from the site at coordinates 17deg E, 60deg N The meteorological station is automatic. e) Meteorological data available and frequency Rainfall: Daily Air temperature: Daily Soil temperature: Daily at Daily depth Wind speed: Daily Net Radiation: Daily Sun hours: Daily Relative humidity: Daily Potential evapotranspiration: Daily f) Archived samples available Archived soil samples: Every second year (some missing) dating from 1956 Archived crop samples: Every second year (some missing) dating from 1956 DATA AVAILABLE IN ELECTRONIC FORMAT Yield data available in electronic format Total above-ground dry matter data available in electronic format Total dry matter offtake data available in electronic format Nitrogen content of offtake data available in electronic format Content of other nutrients in offtake data available in electronic format Total soil carbon data available in electronic format Data available in electronic format for total soil nitrogen Data available in electronic format for rainfall Data available in electronic format for air temperature Data available in electronic format for soil temperature Data available in electronic format for wind speed Data available in electronic format for net radiation Data available in electronic format for sun hours Data available in electronic format for relative humidity This information was compiled for the GCTE-SOMNET Database, Pete Smith, Pete Falloon, David Powlson, and Jo Smith.

Soil Science Department, IACR-Rothamsted, UK.