Effects of Chemical Fertilizer and Microalgae Fertilizer on the Yield and Quality of Understory Panax notoginseng

Purpose To investigate the effects of different chemical fertilizer and microalgae fertilizer application amounts on the yield and quality of understory Panax notoginseng (Burk.) F. H. Chen.

Methods No fertilizer application was used as the blank control (CK), a conventional field chemical fertilizer treatment (CF150) was set, and a microalgae fertilizer treatment (MF150) with equal nitrogen, phosphorus and potassium nutrient inputs as CF150 was established. On this basis, reduced chemical fertilizer treatments (CF75, CF37.5) and increased microalgae fertilizer treatments (MF300, MF600) were further arranged. The yield, saponin content, seedling survival rate, root rot incidence rate, root morphology and soil ammonium nitrogen and nitrate nitrogen content of understory P. notoginseng under different treatments were measured to evaluate the effects of different fertilization techniques on the growth and quality of understory P. notoginseng.

Results Compared with CF150 treatment, MF150 treatment significantly increased the total saponin content of understory P. notoginseng by 34.50%, significantly decreased the root rot incidence rate by 52.05%, and improved the root morphology with significant increases in both root length and root diameter. Compared with CF150 treatment, CF75 treatment had no significant effect on the yield and quality of understory P. notoginseng, and significantly reduced its root rot incidence rate by 36.59%. Compared with MF150 treatment, MF300 treatment significantly increased the total saponin content of understory P. notoginseng by 15.84%. In addition, microalgae fertilizer could improve the soil nutrient environment, compared with chemical fertilizer treatments, it increased soil ammonium nitrogen content by 5.84% to 65.31% and nitrate nitrogen content by 51.47% to 169.83%, respectively.

Conclusion Compared with chemical fertilizer with equivalent nutrients, microalgae fertilizer can significantly increase total saponin content, optimize root morphology and reduce root rot incidence rate of understory P. notoginseng. Moderate reduction of chemical fertilizer application has no significant impact on the yield and quality of P. notoginseng, while increased application of microalgae fertilizer can further improve its yield and quality, proving that microalgae fertilizer has favorable application potential in understory P. notoginseng production.