The Use of Mycorrhizal Fungi to Enhance the Uptake of Phosphorous by Plants

Endo-arbuscular mycorrhizae (AM) are a group of fungi that form symbiotic relationships with plants. They help in absorbing unavailable nutrients from soil. Our research wanted to test if AM could be used to reduce fertilizer application in agriculture. To do so, we inoculated Plantago psyllium plants with AM, treated the plants with one of three different phosphorous fertilizers, phytic acid, potassium phosphate, and iron phosphate, and measured the rate of AM colonization and plant growth. Phytic acid and iron phosphate are common in soil, and potassium phosphate is common in fertilizers. The plants were grown in sterilized sandy soil, and half were inoculated with AM spores by mixing into the substrate. The phosphorous forms were applied via liquid solution, but iron phosphate was mixed in with AM. We then uprooted the plants after about 4 weeks of growth, dried the leaves, and stained the roots. We measured the biomass and calculated the percent of AM colonization. Percentages were measured with a grid system and by counting the number of structures observed. Our results showed that overall plant biomass and growth, and AM colonization rates were highest with iron phosphate. However, the differences in growth and colonization were small due to the limited growing period. More time and experimentation is required to obtain more definitive results, but this knowledge can still be applied to agriculture. If farmers use AM in areas where naturally occurring iron phosphate is prevalent, then hopefully this could reduce fertilizer application rates, reducing ecological damage