The invention relates to a preparation method for controlled-release
fertilizer special for mechanically applied rice. The preparation method comprises the following steps: performing double-layer
coating by using high
tower pelleting compound
fertilizer as core
fertilizer to obtain the corresponding double-layer
coating controlled-release fertilizer I, double-layer
coating controlled-release fertilizer II and double-layer coating controlled-release fertilizer III, wherein the bottom layer
urea coating accounts for 4 to 6 weight percent of the core fertilizer, and the outer layer
film coating agent accounts for 2 weight percent, 4 weight percent and 6 weight percent of the
urea coated fertilizer respectively based on the total weight of the reclaimed
polyethylene film resin and the reclaimed
polystyrene foam resin; and mixing the double-layer coating controlled-release fertilizer I, the double-layer coating controlled-release fertilizer II and the double-layer coating controlled-release fertilizer III according to the
mass ratio of 1:(1-3):(1-2) to obtain the controlled-release fertilizer special for mechanically applied rice. The controlled-release fertilizer special for mechanically applied rice meets the absorption requirements of the rice on
nitrogen,
phosphorus and
potassium nutrients in the growth stage, is difficult to crush and is suitable for mechanical fertilizer application.