Variation of Properties in Surface Soils from a Prior Lake-Bed (Lake Askuris, Greece) Farmed for Over 90 Years.

Twenty-seven soil samples were collected from surface horizons, in order to include representative soil types. Three samples per site were taken and mixed from the examined area, in spring 2005. The study area occupies 820 ha of the now-drained (1910), partially levelled, and continuously farmed Lake Askuris in Greece. The area, which is close to the village of Kalipefki (Longitude: 22° 27' 22'' E; Latitude: 39° 57' 39'' N) and to Mount Olympus, is elevated (≈1000 m) with a Mediterranean climate of mild, rainy winters and hot, dry summers. In addition to clay content, the soils were chemically characterized using 22 soil chemical tests, including pH, total carbon and organic matter, total nitrogen, total sulphur, exchangeable cations, cation exchange capacity, organic and extractable phosphorus (P), and pseudo-total and diethylenetriaminepentaacetic acid (DTPA) extractable trace elements. All of the soil data were skewed, with population mean values higher than the median for clay percentage, cation exchange capacity, carbon/nitrogen ratio, exchangeable calcium (Ca) and magnesium (Mg), DTPA iron (Fe), and total zinc (Zn). A geographic information system and kriging was used to prepare spatially explicit maps (at least two or three level of fertility) for the exchangeable basic cations, the trace elements, phosphorus, organic matter, total nitrogen (N), and total sulfur (S). It is expected these contemporary baseline data will assist the local community and farmers as they consider future nutrient management plans along with other land use options that could include re-flooding the lake bed.” [ABSTRACT FROM AUTHOR]