Soil samples were taken from the 0–20-cm-depth layer, dried at room
temperature and sieved to 2.0 mm. The soil fertility parameter values determined
as described in Raij et al. (2001), were as follows: pH (CaCl2)=
7.5, MO=30.5 g dm−3, P=43.3mgdm−3, K=2.6 mmolc dm−3,