Cucumber seeds were prepared as described above. The soil used in the pot experiment was solarized to minimize the influence of other microorganisms and air-dried prior to the experiment. The dried soil had the following properties: pH 6.7, 0.9% organic matter, 0.1% nitrogen and 4.4% H2O. The organic fertilizer (OF) used in the pot experiment was an amino acid fertilizer made from oil rapeseed cakes that had been enzymatically hydrolyzed by aerobic microbial fermentation at