Phosphate sludge: opportunities for use as a fertilizer in deficient.

Phosphate sludge (PS) is an industrial by-product produced in huge quantities by the phosphate beneficiation plants in Morocco. In order to valorize this by-product, it was examined for its potential use as a soil fertilizer. The physicochemical properties, elemental and mineral content, morphological structure, and component stability of raw PS were investigated. In addition, pathogenicity, phytotoxicity, and the capacity of PS to promote plant growth in deficient sandy soil have been studied. The obtained results showed that PS was characterized by low values of moisture (2.10%), electrical conductivity (EC) (0.77 mS/cm), and organic matter (OM) (0.61%), with a slightly alkaline pH (8.20). Nevertheless, this material carried interesting content of fertilizing elements such as phosphorus (P2O5) of 20.01%, calcium (CaO) of 39.72%, and magnesium (MgO) of 2.33%. Thus, PS did not present any pathogenic or phytotoxic risk with a high increase in tomato plant growth than the control of only soil. In conclusion, the results of this study could provide the primary practical guidance for the PS application in deficient soils characterized by sandy texture.