The effect of combined application of organic and biological fertilizers on the quantitative and qualitative characteristics of Echinacea purpurea under drought stress

This experiment was performed to investigate the effect of microbial inoculation and urea fertilizer on Echinacea purpurea under water stress in two cropping years 2017-2018 and 2018-2019 in Ijan village located in Khondab city of Markazi province.

The experiment was performed in the form of 2 split plots with 3 replications. The first factor included the lack of irrigation in the main plot at 3 levels of 60, 90 and 120 mm evaporation from the Class A evaporation pan. The second factor included animal manure (cattle) in the sub-plot at two levels, no fertilizer and 20 tons per hectare. The third factor of biofertilizer and urea fertilizer in the sub-plot in four levels of application of biofertilizer was Azotobacter+Azospirillum, Mycorrhiza, Aztobacter+Azospirillum+Mycorrhiza and application of urea fertilizer (300 kg ha-1). Flower number and weight, total dry matter yield, chlorophyll, relative water content, proline, catalase, carotenoid, chicoric acid and electrical conductivity of cytoplasmic membrane were measured.

The results showed that the interaction effect of manure and biofertilizer on flower weight was significant. The highest flower weight was obtained in the treatment of combined use of Azotobacter+Azospirillium+ Mycorrhiza and application of animal manure (295.9 and 236.3 g m-2, respectively), which was significantly different from urea consumption. The lowest flower weight was obtained in the treatment of separate mycorrhizal application and non-application of animal manure (0.216 236.3 g.m-2). The difference between the highest flower weight in the mentioned treatment with the lowest value was 36%. In the treatment of non-use of manure, the highest flower weight was obtained in the treatment of Azotobacter+Azospirillium+Mycorrhiza (236.3 g m-2). The interaction effect of manure and biofertilizer on chicory acid was significant. The highest chicoric acid was obtained in the treatment of combined use of Azotobacter+Azospirillium+Mycorrhiza and application of animal manure (7.53 mg g-1 fresh leaf weight). The lowest chicoric acid was obtained in the treatment of separate application of mycorrhiza and no application of animal manure (5.76 mg g-1 fresh leaf weight). The difference between the highest chicoric acid in the mentioned treatment with the lowest amount was equal to 30%. In the treatment of non-application of animal manure, the highest chicoric acid was obtained in the treatment of Azotobacter+Azospirillium+Mycorrhiza (7.17 mg g-1 fresh leaf weight).

In general, microbial inoculation was able to achieve close quantitative and quantitative performance and sometimes more than urea fertilizer treatment, which can be a guide for identifying soil strains and producing biofertilizers compatible for areas with similar climates or soils.