Phosphorus-solubilizing Trichoderma strains: mechanisms to promote soybean growth and support sustainable agroecosystems

Background and aimsBrazilian Cerrado soils have low phosphorus content, leading many farmers to frequently apply fertilizers. With respect to this, Trichoderma are fungi with traits that can improve the fertility and health of the soil and promote plant growth. In this study, native strains of Trichoderma (T. viride GT-8, T. reesei GT-31, and T. longibrachiatum GT-32) from the Brazilian Cerrado were characterized. The impact of their inoculation on soybean growth and grain yield was also assessed under two phosphate fertilization conditions: 400 and 200 kg ha-1 of simple superphosphate (SPP). Two independent field experiments were conducted with the cultivars Nidera NS6601 IPRO and DM 69IX60RSF 12X RR2PRO. Leaf and rhizospheric soil samples were collected for biochemical analyses.ResultsThe strains showed phosphate solubilization from fertilizers and exhibited other PGP traits. Inoculation of GT-32 on cv. Nidera NS6601 resulted in a 4.5% increase in grain yield under 200 kg ha-1 of SPP. For the second cultivar, the use of GT-31 and GT-32 at 200 kg ha-1 of SSP resulted in grain yield increases of 22.7% and 18.6%, respectively. Inoculated plants showed higher shoot dry weight, chlorophyll content, phenolic compounds, and antioxidant responses under both fertilization conditions. Furthermore, enzymatic activities were higher in the rhizospheric soil of plants inoculated with GT-31 and GT-32 strains.ConclusionThese findings demonstrated the potential of the GT-31 and GT-32 strains to improve soybean growth and yield with reduced fertilizer use. Additionally, their use could offer a sustainable strategy for enhancing soil health and fertility in Brazilian Cerrado soils.