Fig. 3.

(a) Scanning electron microscopy image of temperature-responsive controlled-release iron fertilizer (TCIF). (b) Temperature-response mechanism of TCIF enabled by temperature-sensitive polymer F-127 grafted on the surface of porous amino silicon oil (ASO) shell. The TCIF exhibited (c) temperature-dependent controlled release of Fe(II) and led to (d) increased Fe content in maize shoots as compared to control (CK) in a temperature-dependent manner. Panels a–d adapted with permission from ref. [126]. Copyright (2018) Elsevier.