Nutrient content amelioration in red lettuce growing in nutrient deficient soils via arbuscular mycorrhizal fungi

Comparing the effect of mycorrhizal fungi inoculation with different levels of chemical fertilizers on increasing yield and absorption of nutrients in order to achieve an environmentally friendly method to reduce the use of chemical fertilizers in lettuce cultivation in poor soils.

In this study, to improve the nutritional quality of red lettuce under poor soil conditions, the effects of arbuscular mycorrhizal (Funneliformis mosseae, Rhizophagus intraradices, and a combination of both) colonization and chemical fertilizer were compared using two different methods.

The results showed that the seed coating method increased fresh yield of lettuce, which was more effective than NPK 25 and 50% in both seasons. The most beneficial effects of soil inoculation and seed coating on colonization percentages were measured when lettuce plants were inoculated with Funneliformis mosseae species. The greatest root length was observed when seed coating method was used to inoculate lettuce plants with Funneliformis mosseae. The highest root volume was observed when lettuce plants were inoculated with combined mycorrhizal treatment in the seed coating method and NPK 100%. In both growing seasons, the concentration of N, P, K, Ca, and Mg were increased in plants treated with mycorrhizal fungi and NPK-fertilizer compared to untreated plants.

Finally, the combined mycorrhizal treatment resulted significantly decrease in nitrate accumulation. So, to increase food safety, and protect the environment, it is recommended to use mycorrhizal fungi, especially combined mycorrhizal treatment (Funneliformis mosseae + Rhizophagus intraradices), alternative 25 up to 50% of chemical fertilizers in lettuce culture.