Study on the Revitalization Potential of Thermal-treated Soils

A pot experiment was set up at the Experimental Farm of the Faculty of Horticultural Sciences of the Szent István University in 2001 investigating the revitalization effect of selected treatments on thermal-treated soils and other production substances. In the experiment 6 factors and 7 treatments were used, each in 4 replicates, using rape (Brassica napus DC) as test plant. During the time period of the experiment (29 May-17 August) continuous observations and measurements were conducted, plant and soil analyses - chemical and microbiological - were made to establish the main effects and results of the different treatments. These are discussed in the paper in detail. Although the soil-vitalization procedures were of great success, no treatment in the experiment had an extremely positive effect. Various additives, however could enhance the re-colonization processes significantly. According to the basic factors (the soils or substrates) the best treatments were: the A1 (clay-pearl) additive and the C2, C3 factors (the medium and low temperature soil treatments). Among the treatment combinations, treatments IV and VII were the best (compost and compost + inocula addition). This fact shows that the compost in a good quality, and the compost enriched, compost extracted microbial inocula can play the most important role in the revitalization of thermal-treated soils. Manure addition and the manure + inocula treatment can also be used as a prominent treatment in the restoration, to increase the organic matter content and the microbial activity in soils. The single alga- and microbial inocula treatment was not successful permanently, therefore their use - without adding any parallel organic matter - cannot be recommended. Investigations of the soil microbial activity showed that the lowest temperature of thermal treatments had resulted a more effective revitalization. The clay-pearl additive increased the persistency and activity of the microbes in the soil. It was also obviously found that the organic additives with or without the microbial inoculations could be used potentially as the best soil revitalization treatments.