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SPADE2 PROJECT OBJECTIVES. Expand the ‘Estimated’ soil profile database to include ‘primary soil properties for ALL STU’s. Primary Soil Properties are: clay%, silt%, fine sand%, medium sand%, coarse sand%, organic carbon%, pH, Bulk density. SPADE2 Project & Database administration.
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SPADE2PROJECT OBJECTIVES • Expand the ‘Estimated’ soil profile database to include ‘primary soil properties for ALL STU’s. • Primary Soil Properties are:clay%, silt%, fine sand%, medium sand%, coarse sand%, organic carbon%, pH, Bulk density.
SPADE2Project & Database administration • Funded by ECPA. • Co-ordinated by National Soil Resources Institute, Cranfield University, UK(Project manager. J.M. Hollis). • Sub-contracts to National data providers. • In principle agreement between ECPA and ESB that SPADE 2 data will be included in the next version of the European Soil Database.
SPADE-2 – Project Overview • All National data providers contacted about participation. • Negative response from Austria & no reply from Greece (even after several contacts!). • Project started November, 2002. • Protocols for data generation and formal sub-contracts sent to National data providers. • Data providers from France, Spain, Sweden & Ireland did not respond to sub-contracts. • All other countries (Belgium & Luxembourg, Denmark, Finland, Germany, Italy, Netherlands, Portugal, UK) completed data supply by March 2004).
Data provided – How compatible? WB Walkley Black methodDr C Dry combustion (Loss on Ignition)CHN CHN Analyzer
Data Validation • Particle size data checked for errors (Sum of all values =100% + 1%). • An automated curve fitting routine used to harmonise the particle size data points at0.002, 0.05, 0.1, 0.2, 0.5, 2 mm. • Organic carbon content, pH and bulk density checked against soil type land use combinations and population distributions plotted to identify ‘outliers’.
Evaluation of SPADE-2 Particle-size data • Curve fitting exercise using a logistic curve showed that significant amounts of data give an unacceptable fit. • Unlikely that any constant-form curve will give better results. • A revised procedure developed:- For each data set, mean diameter data transformed to a Log ‘Phi’ value. F = -log2d = -{log10d / log102} where d is the mean diameter.- A ‘monotonic cubic spline interpolation’ used to derive data points at standard mean diameter intervals from data points.
500 mm Monotonic cubic spline fits -1 2000 mm 250 mm 50 mm 2 mm
2000 mm 200 mm 50 mm 2 mm Monotonic cubic spline fits -2
2000 mm 210 mm 50 mm 2 mm Monotonic cubic spline fits -3 105 mm
2000 mm 600 mm 200 mm 60 mm 2 mm Monotonic cubic spline fits -4
Evaluation of SPADE-2 Org. C. data • Overall trends in the data are compatible with other ‘national’ datasets. • Data distributions for groupings of soil types is also compatible.
SPADE-2 pH Data All pH data provided as pH in Water (1 : 2.5 H2O) apart from the Netherlands (KCl).
SPADE-2 – future work • Database and Guidance document completed by November 30th. • Extension to central European countries.Poland, Hungary, Czech Republic, Slovakia, Estonia, Latvia, Lithuania, Slovenia, Romania, Bulgaria, Croatia, Serbia.Using established methodology. • Continue efforts to derive data for those countries that have not contributed so far (France, Ireland, Sweden, Greece & Spain).