Recent evolution and trends in the soil fertility of Flemish vegetable fields (1998-2012)

The Soil Service of Belgium (SSB, spin-off of the KU Leuven) formulates each year thousands of fertilization recommendations based on soil analyses. Soil samples are taken in the ploughing layer (0-23 cm) in order to determine the overall soil fertility (pH, C, P, K, Mg, Ca, Na). Liming and fertilization recommendations are then calculated by the BEMEX expert system. In the last 15 years (1989 - 2011), SSB determined the soil fertility of more than 65 000 soil samples from fields with typical vegetable rotations. The samples originated from the whole of Flanders, but especially from the sandy-loam and sandy soils in West-Flanders (the major vegetable-growing area in Flanders). Fertilization recommendations were calculated mainly for Brussels sprouts, leek, cauliflower, spinach and carrots. In this contribution, the statistics and trends of the soil fertility are discussed for cauliflower and leek.