Sustainable utilization of phosphogypsum in agriculture enhanced by mycorrhizal organisms: a new perspective

Background Arbuscular mycorrhizal fungi (AMF) could promote plant growth and nutrients absorption, and had a certain resistance to arsenic pollution from soil. Phosphogypsum (PG) could provide the necessary elements for crop growth because of containing nutrients such as phosphorus (P), sulfur (S) et al. but PG contained arsenic (As) also could bright pollution risk to crop growth.This study investigated the synergy of AMF and PG on the growth and nutrient absorption of tobacco ( Nicotiana tabacum L.) and evaluated the risk of arsenic (As) accumulation. Results Results showed thatindependent of AMF inoculation, PG addition significantly increased shoot biomass in ‘NC297’ plants, significantly increased the plant S concentration and absorbed amount, and the S specific absorption rate of ‘KRK26’ plants. In response to each PG addition level and compared to the uninoculated treatment, FM inoculation significantly increased the P specific absorption rate, GA inoculation significantly increased the P concentration and absorbed amount of ‘KRK26’ plants. Furthermore, GA inoculation significantly decreased the shoot As concentration and uptake, thus significantly increasing the absorption ratio of P to As in ‘KRK26’ shoots.Principal component analysis (PCA) showed soil pH contributed significantly to the two principal components extracted.Pearson correlation analysisindicated that a significant positive correlation between root P uptake,root S uptake and soil available P respectively, and soil available As content was significantly negatively correlated with soil pH, indicating that PG could reduce the bioavailability of arsenic by increasing pH. Conclusion When PG addition with AMF inoculation was applied to soils with S and P deficiency, a better effect was found for PG40 addition-GA inoculation combination treatment for promoting plant growth and P and S uptake by ‘KRK26’ plants. And PG could reduce the As bioavailability by increasing pH value. It is conducive to the safety and sustainable development of the agricultural ecological environment.