Effectiveness of Phosphate-Solubilizing Aspergillus fumigatus MCC 1721 in Boosting Fenugreek Yield in Red Laterite Soil

Phosphorus is an essential nutrient vital for the growth of plants, rapidly becomes immobile and inaccessible to plants when applied as fertilizer. Rock phosphate (RP), abundantly present in Indian soils, serves as phosphate source. Phosphate-solubilizing fungi (PSF) possess the capacity to solubilize insoluble forms of phosphate, rendering it bioavailable and thereby enhancing plant growth. PSF were isolated and screened based on in vitro plant growth-promoting traits. The best-performing strain was identified using molecular tools. The phosphate-solubilizing capacity of the selected isolate was assessed in vitro. A 2-year field experiment was conducted to investigate the impact of RP and PSF, alone or together on fenugreek in red laterite soil. The result was compared against the use of chemical fertilizer (di-ammonium phosphate) and arbuscular mycorrhizal fungus (Funneliformis mosseae) focusing primarily on crop yield and soil fertility. Six PSF were obtained among them AP2 was selected and identified as Aspergillus fumigatus. AP2 demonstrated significant growth promoting properties and effectively solubilized various insoluble phosphate forms. Additionally, AP2 produced acid phosphatase and various organic acids while growing with different insoluble phosphate. The combined application of AP2 alongside RP fertilization showed enhanced growth and total phosphate uptake in fenugreek, surpassing the effects of other treatments. Moreover, soil fertility exhibited notable improvement where AP2 were inoculated alongside RP fertilization compared to other treatments. The findings suggested that incorporating AP2 with RP fertilization offers a promising solution for farmers seeking to reduce dependence on chemical phosphorus fertilizers while advocating for environmentally-friendly agricultural practice.