Effects of fulvic acid on rice growth and phosphorus absorption

Fulvic acid (FA) is a complex substance with multiple functional groups produced by organic waste composition. It can promote plant growth and affect phosphorus (P) fertilizer. However, the mechanism of its action and the optimal application rate of FA have remained unclear. This study set different concentrations of FA to explore the effect on rice growth and P. These results indicated exogenous addition FA can significantly increase plant height, chlorophyll concentration and biomass, and the P content, P uptake and distribution in different rice plant parts. Moreover, FA treatments improved root morphogenesis and the expression of transcript-level P transporter genes (OsPHT1s). Different concentrations of FA treatments had different effects on rice, especially T1 (40 mg/L) treatment had the best. In conclusion, basic nutrients and the addition into FA at moderate doses can promote root growth and phosphorus utilization to improve rice growth. Therefore, FA can be used as an effective component of a new type biological phosphorus fertilizer designed for sustainable agricultural production.