while polymer coatings (e.g. polyolefin) are expected to exhibit the
diffusion release mechanism.
A pictographic representation of bothmechanisms is given in Fig. 2.
The controlled release of nutrients also depends on ambient temperature
and moisture with the release rate increasing at higher temperatures
with greater moisture content [10]. The coated fertilizer release
mechanism is basically a nutrient transfer from the fertilizer–polymer
interface to the polymer–soil interface, driven by water. The governing
parameters for the release mechanism are: (i) diffusion/swelling; (ii)
degradation of the polymer coating, and (iii) fracture or dissolution. A
similar release mechanism was presented by Guo [12], Liang [13], Liu
[14], andWu [15].