Different treatments for increasing sustainability in soilless culture

The possibilities of increasing sustainability in substrate culture by using closed system, lower levels of the nutrients and microorganisms were studied in the trials carried out during autumn season in 2003 and spring season in 2004. Plant material was tomato cv. Durinta and perlite was used as growing medium. The experimental design was split-split-plots with 3 replicates. The treatments were as follows: (1) nutrition systems (open and closed), (2) concentrations of nutrient solution (full and half -1/2 of macroelements-), (3) microorganisms (Bacillus subtilis FZB24, Trichoderma harzianum T-22, control -no microorganism-). Parameters related to yield, fruit quality and water use efficiency -WUE- were evaluated. Half nutrient levels were found to be adequate in open system, whereas full nutrient levels gave better results in closed system. Although 13.7% higher yield could be obtained in Bacillus treatment compared with control in open system, Bacillus subtilis gave rise to decreased yield in closed system. Generally, there were no significant differences between Trichoderma harzianum treated and control plants in respect to yield.