The Influence of Chemical, Organic and Biological Fertilizers on Agrobiological and Antioxidant Properties of Syrian Cephalaria ( Cephalaria syriaca L.)

: Since chemical fertilizers pollute soil, water and crops, conscientious agricultural producers seek alternatives to chemical fertilizers. Biological fertilizers are considered a reliable alternative for improving soil productivity and plant growth in sustainable agriculture. The response of some agrobiological and antioxidant properties of Syrian cephalaria ( Cephalaria syriaca L.) to different fertilizer sources was explored in an experiment which included: (i) mycorrhiza + manure; (ii) mycorrhiza + vermicompost; (iii) mycorrhiza + Azotobacter; (iv) mycorrhiza + chemical fertilizer; (v) mycorrhiza; and (vi) control. The results showed that the highest seed yield, biological yield, oil percentage yield, were observed in plants treated with mycorrhiza + vermicompost, whereas the highest 1000-seed weight was obtained from the application of mycorrhiza + manure. With respect to photosynthesizing pigments, the application of mycorrhiza + vermicompost increased chlorophyll a , chlorophyll b , total chlorophyll, carotenoid content as well as total phenols, total flavonoids and DPPH antioxidant activity as compared to control (unfertilized) plants. The mixed application of different fertilizer sources influenced the uptake of trace elements (Fe, Zn and Cu) optimally. In the light of the obtained results for the agrobiological and antioxidant properties of Syrian cephalaria, in most of the measured traits, there is no significant difference between manure, vermicompost and chemical fertilizers in combination with mycorrhiza. Hence the use of organic and biological inputs instead of chemical fertilizer for improving crop efficiency and quality with the aim of alleviating pollution and accomplishing sustainable agriculture is highly encouraging. fungi fungi g


Introduction
Syrian cephalaria (Cephalaria syriaca L.) is an annual plant that grows to the height of 40-110 cm in natural conditions. The taproot of this species can penetrate 60-120 cm into the soil. The hollow and strong stems of the plant grow vertically. The stem and leaves are covered with 4-5 mm hairs. The species has a high branching potential. Since reproductive organs appear at the end of the main branch and auxiliary branches, there is a direct relationship between seed yield and branch number. optimum moisture level (field capacity) and leveled. Organic, Phosphorus and Potassium fertilizers were used at pre-sowing in autumn, according to soil analysis and farrowed in 50 cm. The experimental treatments were composed of two biological fertilizers and their mixture as well as vermicompost (6.8 ton ha −1 ), manure (6.3 ton ha −1 ) and chemical fertilizer (Urea: 110 kg ha −1 + Triple superphosphate: 60 kg ha −1 + Potassium sulfate: 50 kg ha -1 + Micronutrients: 23 kg ha −1 ), including (a) mycorrhiza fungus + manure, (b) mycorrhiza + vermicompost, (c) mycorrhiza + Azotobacter, (d) mycorrhiza + chemical fertilizer, (e) mycorrhiza and (f) control. The fertilizer treatments were applied to the plots as per the research plan. The fertilizers were used according to the fertilizers program of the crops which have same canopy, based on the soil analyses of the research farm. The seeds of Syrian cephalaria were supplied by the food industry group of Ankara University. One hour before sowing, the seeds were inoculated with Azotobacter biological fertilizer, which contained an effective N fixing bacterium from Aztobacter vinelandi (concentration formulated product: 10 9 CFU/g), as per the guidelines of Green Biotech Ltd. firm. To this end, the package content was mixed with water and it was sprayed on the seeds so long that a uniform cover was formed on the seeds. Then, the seeds were dried in shadow before sowing. The soil containing the mycorrhiza fungi (Rhizophagus intraradices) (prepared in Organic Plant Protection Clinics, Asababad County, Hamedan, Iran; concentration formulated product: 300 CFU/g) in the amount of 35 g plant −1 was placed under the seeds before sowing. Between-row spacing was set at 25 cm and on-row spacing at 10 cm. The seeds were sown in mid-March. Urea fertilizer was used two times (pre-sowing in mid-March and mid-May), according to soil analysis. They had 94% vigor. Before the trial, soil of research farm was sampled at the depth 0-30 cm to determine its physical and chemical properties (Table 1). Along with that, the basic physico-chemical properties of organic fertilizers used in the trial are given (Table 2), as well as the outdoors climatic data of the experimental city Urmia (Table 3).

Measurement of Growth Parameters
All agronomic practices were performed uniformly for all treatments. After full maturity (in late July), all experimental treatments were separately harvested, and their yield and yield components were recorded. The agronomic traits of seed yield, biological yield, harvest index and 1000-seed weight were recorded on 10 plants per plot at physiological maturity and during harvest. The samples were first oven-dried at 70°C for 24 hours and then, they were examined. Traits such as chlorophyll a, chlorophyll b, total chlorophyll and carotenoid were determined as reported in literature [15]; the samples were obtained from upper evolved young leaves at the end of flowering stage and two days after irrigation, in the afternoon.

Determination of Total Phenol and Flavonoid Contents and Anti-Oxidant Activity
Total phenol content of the seeds was determined using the Folin-Ciocalteu reagent [16]. Also, flavonoid content in the extracts was estimated by the literature procedure [17]. To measure antioxidant activity, the readings of sample absorption was converted to DPPH free radical inhibition percentage

Trace Elements Analysis
The absorption of trace elements was determined in fresh digestion extract using their standards with an atomic absorption device (Shimadzu-Tokyo-Japan AA6300) they were read in mg L −1 and were calculated in mg kg −1 [19,20].

Statistical Analysis
After the data were normalized, they were subjected to the combined analysis by the SAS 9.1 software package. Also, means were compared by Duncan's Multiple Range Test at the p<0.05 level.

Agrobiological Properties
The significant differences were observed for studied agrobiological properties which can be attributed to the application of different fertilizers (p < 0.05). The results are summarized in Table 4. The highest 1000-seed weight was 15.88 g observed in plants treated with mycorrhiza fungi + manure but this treatment did not significantly differ (p < 0.05) from mycorrhiza fungi + vermicompost. The lowest 1000-seed weight of 11.99 g was obtained from control (no fertilizer use). However, the application of mycorrhiza fungi alone and control treatment had similar impacts on this trait.
The highest biological yield of 26.98 g plant -1 was related to the integrated use of mycorrhiza and vermicompost so the integrated application of various fertilizer sources had a similar effect on the biological yield of Syrian cephalaria. The control treatment exhibited the lowest biological yield of 16.86 g plant −1 .
Seed yield was also influenced by fertilizer treatments and the highest seed yield of 12.07 g plant -1 was related the integrated application of mycorrhiza fungi and vermicompost, whereas the lowest one (5.99 g plant −1 ) was observed in control (unfertilized) plants.
The highest harvest index of 44.75% was obtained from the plants treated with mycorrhiza fungi + vermicompost. The mixed application of mycorrhizal fungi with organic, biological and chemical fertilizers had the similar effect on seed harvest index. The lowest harvest index was 36.17% observed in control (unfertilized) treatment (p < 0.05).
Plants treated with mycorrhizal fungi + vermicompost produced the highest oil percentage of 25.15% but it did not differ significantly from the mixed application of mycorrhizal fungi and organic, biological and chemical fertilizers. Unfertilized plants showed the lowest oil percentage of 19.32%.
Means comparison revealed that the integrated treatment of mycorrhiza fungi + vermicompost was related to the highest oil yield of 2.99 g plant -1 but it did not differ significantly from the application of mycorrhiza fungi + manure and mycorrhiza fungi + chemical fertilizer. The lowest oil yield of 1.18 g plant -1 was observed in control plants (p < 0.05).

19
The results of analysis of variance (ANOVA) showed that studied agrobiological traits were 20 influenced by fertilizer treatments (Table 5).

29
The concurrent application of mycorrhiza + vermicompost produced the highest total phenol 30 content (TPC) of 27.89 mg gallic acids equivalents per g DM (dry matter) but this did not differ 31 significantly from the integrated use of mycorrhiza fungi + manure (p < 0.05). Control had the lowest 32 TPC of 21.08 mg gallic acids equivalents per g DM (Table 6).

33
The highest total flavonoid content (TFC) of 0.56 mg quercetin per g DM, was obtained from the 34 application of mycorrhiza fungi + manure and the lowest, 0.45 mg quercetin per g DM, from control 35 (unfertilized) plants (p < 0.05, Table 6).

36
Means comparisons showed that the highest antioxidant activity (DPPH free radical inhibition) 37 of 60.16% was observed in the simultaneous application of mycorrhiza and vermicompost and the 38 lowest was 47.10% observed in control (unfertilized) plants (Table 6). Seemingly, mycorrhiza +   Table 6). The application of mycorrhiza + vermicompost was related to the highest Cu content (32.44 mg kg −1 ) but it did not show a statistically significant difference with mycorrhiza + manure. The lowest Cu content of 22.98 mg kg −1 was observed in control plants (Table 6).

56
The results of ANOVA revealed that fertilizer treatments significantly influenced the 57 antioxidant properties of Syrian cephalaria (TPC, TFC and DPPH free radical inhibition) (p < 0.01).

58
Moreover, the concentrations of trace elements (Fe, Cu and Zn) were significantly affected by 59 fertilizer treatments (p < 0.01, Table 7).

73
The obtained results indicated that the biological yield was higher when the plants were

112
Consequently, it contributes to high seed yield as well as high oil yield. Oil yield is the main goal in 113 planting and development of oilseeds including Syrian cephalaria.

114
It seems that when organic, biological and chemical fertilizers are applied simultaneously, the 115 N requirement of the plant is met, and N wastage is reduced. Then, because of the mineralization 116 process, N starts to turn into absorbable form gradually and thereby, the vegetative growth of the 117 plant is improved during the growth period. As such, more chlorophyll is synthesized in plants 118 exposed to integrated fertilizer regime. It has been reported that when plants were fed with biological 119 and chemical fertilizers, they absorbed more N and produced more chlorophyll; then, they exhibited 120 higher sunlight absorption capacity, photosynthate synthesis and growth and yield [35]. In the 121 present study, the fact that the application of organic and biological fertilizers enhanced leaf chlorophyll synthesis and concentration can be attributed to its role in hindering N leaching and its Phenol compounds are usually determined by genetic factors and environmental conditions including nutrition [37]. It has been reported that phenol content of fennel was increased by the application of 50% chemical fertilizer + 50% organic fertilizer + biological fertilizer versus control [38].

129
The increase in the nutrients of soil treated with manure contributes to increasing net photosynthesis