| dc.description.abstract | The present study illustrates the effect of biofertilizer and chemical fertilizer applications on the microbiological properties of the soil, the yield-related characteristics, phenolic fruit composition and antioxidant capacity of 'Clery' 'Joly' and 'Dely' strawberries under greenhouse conditions. Plants were treated with biofertilizer (liquid inoculum combined of Azotobacter, Derxia and Bacillus genera) and chemical fertilizer (Polyfeed NPK Water Soluble Fertilizer). The microbiological properties of soil were monitored by determining the total microbial count, numbers of soil fungi, actinomycetes, oligonitrophilic bacteria and Azotobacter using indirect counting methods involving plating out a soil suspension onto appropriate selective culture media. The yield-related characteristics of the tested plants were evaluated for generative potential parameters and morphometric traits. Since strawberry fruits are important sources of health-related compounds, special attention was given to the total phenolics content as well as to identified individual polyphenolic compounds, and consequently to the total antioxidant capacity. The results obtained suggested that application of the biofertilizer induced the highest increase in the numbers of oligonitrophilic bacteria and Azotobacter, whereas soil fungal and actinomycetes count significantly decreased. Significantly higher values of fruit weight, length and width were obtained in the chemical fertilizer treatment. Application of biofertilizer has given the best results in terms of anthocyanins and kaempferol content, as well as the content of ellagic, gallic, and protocatechuic acids. The positive influence of biofertilizer on the level of total phenolics and consequently on the total antioxidant capacity was clearly expressed. Considering the biological properties of the examined soil and fruit quality characteristics, certain amounts of mineral nitrogen can be replaced with biological nitrogen in order to obtain healthy and environmentaly-safe products. | en |
