Effects of Trichoderma harzianum T83 on Suaeda salsa L. in coastal saline soil

Sustainable biotechnological techniques can transform coastal saline soil into agriculturally viable soil. In the current study, the T83 strain of Trichoderma harzianum was isolated and shown to promote growth of Suaeda salsa L., a halophytic species. We assayed the effects of T83 conidia powder and fertilizer on the physiology of S. salsa as well as the physical and biological properties of the treated soil. Compared to the control plants, the experimental S. salsa plants that received conidia powder and fertilizer exhibited increased fresh masses by 50.5% and 82.7% and increased dry masses by 67.3% and 119.3%, respectively (P < 0.05). The concentrations of proline, organic acids, amino acids, soluble sugars, K+, and Ca2+ were increased in conidia powder and fertilizer treatments (P < 0.05), and increased by 77.5%, 58.3%, 86.9%, 58.7%, 79.3% and 38.8% in fertilizer treatment, respectively. Both powder and fertilizer treatments significantly increased the enzyme activity of peroxidase and superoxide dismutase as well as root vigor (P < 0.05) and decreased malondialdehyde concentration (P < 0.05). Additionally, fertilizer treatments increased enzyme activity of phenol oxidase and catalase. Conidia powder and fertilizer treatments significantly decreased soil bulk density and soil salt concentration, while increasing soil total porosity and field water capacity (P < 0.05). Powder and fertilizer significantly (P < 0.05) increased the populations of total bacteria, total actinomyces, total fungi, ammonifying bacteria (AB), nitrifying bacteria (NB), phosphate-solubilizing bacteria (PHB), and potassium-solubilizing bacteria (PTB). Compared to the control, the fertilizer treatment exhibited populations of total bacteria, total actinomyces, total fungi, AB, NB, PHB, and PTB that had increased by factors of 9.2, 55.9, 6.0, 21.1, 4.0, 9.2 and 5.2, respectively. The T83 fertilizer effectively promoted the growth of S. salsa in saline soil and improved the coastal saline soil quality.