Phosphate fertilizers coated with phosphate-solubilising Trichoderma harzianum increase phosphorus uptake and growth of Zea mays

Background and scope: Enriching phosphorus (P) fertilizers with phosphate-solubilizing microorganisms (PSM) can be a promising strategy to enhance P-use efficiency in agriculture. However, the effects of these microorganisms when applied in mixtures or coating P fertilizers needs further investigation. In this work, we coated a Rock Phosphate (RP) or soluble P fertilizer (Triple Superphosphate -TS) with Trichoderma harzianum, to enhance plant P uptake and growth of corn (Zea mays). Results: The addition of T. harzianum to RP and TS reduced soil pH and increased the activity of soil acid and alkaline phosphatases which are important mechanisms involved in P mobilization by PSM. Trichoderma harzianum increased plant root length, root surface area and total root dry mass (17%). Trichoderma harzianum also increased plant P content (34%) and total dry matter content (22%) of plants fertilized with soluble phosphate (TS). Conclusion: Our main findings provide evidence that coating fertilizers with T. harzianum can be an effective way to enhance plant growth and P-use efficiency in agricultural systems. Importantly, we show that joint application with fertilizer did not impair important mechanisms of P mobilization by T. harzianum. Further research, in the field and under different environmental conditions, is necessary to validate the technology.