Controlled Release of Phosphate from Layered Double Hydroxide Structures: Dynamics in Soil and Application as Smart Fertilizer

Author(s)

Bernardo, Marcela P. ^{[1, 2]} ; Guimaraes, Gelton G. F. ^[2] ; Majaron, Vinicius F. ^{[1, 2]} ; Ribeiro, Caue ^{[1, 2]}

Affiliation

^[1] Univ Fed Sao Carlos, Chem Dept, Rod Washington Luis S-N, BR-13565905 Sao Carlos, SP - Brazil

^[2] Brazilian Agr Res Corp, Embrapa Instrumentat, R 15 Novembro St, 1452, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: ACS SUSTAINABLE CHEMISTRY & ENGINEERING; v. 6, n. 4, p. 5152-5161, APR 2018.
• Web of Science Citations: 14

Abstract

A route is proposed to produce a hydrotalcite-like layered double hydroxide structure ({[}Mg-Al]-LDH) for phosphate fertilization. The mechanism of controlled phosphate release from the structure was investigated. The preparation strategy resulted in a phosphorus content of around 40 mg.g(-1) LDH, which was higher than previously reported for related fertilizers. The release of phosphate into water from {[}Mg-Al-PO4]-LDH continued over a 10-fold longer period, compared to release from KH2PO4. Analysis using P-31 NMR elucidated the nature of the interactions of phosphate with the LDH matrix. In soil experiments, the main interaction of P was with Fe3+, while the Al3+ content of LDH had no effect on immobilization of the nutrient. Assays of wheat (Triticum aestivum) growth showed that {[}Mg-Al-PO4]-LDH was able to provide the same level of phosphate nutrition as other typical sources during short periods, while maintaining higher availability of phosphate over longer periods. These characteristics confirmed the potential of this preparation route for producing controlled release fertilizers, and also revealed fundamental aspects concerning the interactions of phosphate within these structures. (AU)

• FAPESP's process: 16/09343-6 - DEVELOPMENT AND AGRONOMIC EVALUATION OF A NEW FERTILIZER BASED ON NANOCOMPOSITES SULFUR-PHOSPHATE MINERAL
• Grantee: Gelton Geraldo Fernandes Guimarães
• Support type: Scholarships in Brazil - Post-Doctorate