In order to implement project activities within the Work Package 4 (WP4 – Green lighting of selected soil improvers in protected environments) Plant Growth Chamber JSPG-1500C was purchased. The purchase was financed by means of financial support from the Science Fund of the Republic of Serbia through the PRIZMA program. The main goal of Work Package 4 is to test the effectiveness of a set of newly formulated soil improvers – plant probiotics on maize seedlings in controlled conditions of the climate chamber.