Agriculture Reference
In-Depth Information
Fig. 5.4 Schematic stages of the release of a pesticide from a one-dimensional porous solid
matrix. The inner part of the matrix is at the upper end of the rectangle, and the area of contact with
water is at the bottom.
Black zones
denote the undissolved pesticide and
gray zones
the dissolved
pesticide inside the porous matrix.
L
denotes the distance from the granule surface to the solubility
front of the active ingredient within the granule, and
L
c
is the critical length at which the
anomalous diffusion can occur. Case-II transport (a), anomalous diffusion (b), Fickian
diffusion-controlled transport (c), and exhaustion (d) (Paradelo et al.
2012
). Reproduced by
permission of Elsevier
controlled release of fertilizers, an ideal system would be capable of controlling
their delivery to coincide with the desired amount of the plant (Wu
2013
) to avoid
considerable losses due to leaching, evaporation, and other aspects of the weather.
The formulations used in these technologies were obtained by the physical mixing
or chemical binding of the active agent to the matrix (Kenawy and Sakran
2001
).
