Foliar Spray or Soil Drench: Microalgae Application Impacts on Soil Microbiology, Morpho-Physiological and Biochemical Responses, Oil and Fatty Acid Profiles of Chia Plants under Alkaline Stress

Abstract

Alkaline soil inhibits the growth and productivity of chia plants (Salvia hispanica L.). Microalgae as biofertilizers have been reported to induce alkalinity tolerance and enhance yield and quality. However, limited information is known concerning the influence of microalgae application on medical plants, including chia. Our experiments were performed to evaluate the effect of microalgae strains of Arthrospira platensis, Chlorella vulgaris, Nostoc muscorum, and Anabaena azollae with two application methods, foliar spray and soil drench, on morpho-physiological and biochemical parameters, yield, seed and oil quality, and fatty acid profiles of chia plants cultivated under alkaline soil conditions, as well as the on soil microbial activity. The results obtained reveal that both application methods positively influenced the growth and productivity of chia plants. However, the foliar application showed significant differences in the herb’s fresh and dry weights and leaf pigments, whereas the drenching application caused more effect than the foliar spray application at the reproductive stage. Untreated chia plants showed a slight decline in the growth, productivity, and antioxidant level with an increase in Na content. However, microalgae applications significantly ameliorated these impacts as they induced an enhancement in the growth, leaf pigments, total protein and carbohydrate contents, nutrient content, seed and oil yields, as well as an increase in linolenic and linoleic fatty acids, with a reduction in saturated fatty acids, namely, palmitic and lauric acid. Soil drenching generated an improvement in the soil microbial activity and caused a reduction in the pH. The treatment of A. platensis with drenching application resulted in higher seed and oil yield, with an increase of 124 and 263.3% in seed and oil yield, respectively.

Underlying Mechanisms of Action to Improve Plant Growth and Fruit Quality in Crops under Alkaline Stress

“…Similarly, biochar combined with daily fertigation in alkaline soil can improve cucumber yield [101]. Similarly, microorganisms are another window of action to mitigate alkalinity damage, as they increase antioxidant enzymes and modify plant gene expression [108], regulate enzyme activity and soil microbial load [27,109], decrease pH [110], and regulate soil ionic balance [111,112], improving nutrient availability [113]. All of these management techniques improve plant productivity and promote better fruit quality by increasing the total soluble solids, acid ratio, sugar, and phenol content [42,114].…”

Essential oils prolonged the cut carnation longevity by limiting the xylem blockage and enhancing the physiological and biochemical levels

“…This in turn can be attributed to an increase in glucose synthesis and cellular activity [55]. Chlorophyll degradation is minimized when the glucose content is increased via osmotic pressure and respiration management [56][57][58]. Essential oils have antimicrobial property which prevents the growth of microbes that possess chlorophyllase activity, thereby preventing the degradation of chlorophyll [59,60].…”

Correction: Youssef et al. Foliar Spray or Soil Drench: Microalgae Application Impacts on Soil Microbiology, Morpho-Physiological and Biochemical Responses, Oil and Fatty Acid Profiles of Chia Plants under Alkaline Stress. Biology 2022, 11, 1844

“…There were three errors in the original publication [ 1 ]. ** By mistake, we copied them from another study that we are currently testing ** .…”