This invention discloses a slow-release granule formulation of
sodium alginate-
biochar loaded with
thiamethoxam, its preparation method, and its application. The slow-release granule uses
biochar as the adsorbent carrier to adsorb
thiamethoxam and
sodium alginate as the encapsulating material, which is then cross-linked and solidified by dripping
calcium chloride solution. The
mass ratio of
biochar to
thiamethoxam is (10~30):1, the
mass-to-volume ratio of
sodium alginate to water is 1.5~2.0 g:100 mL, and the concentration of the
calcium chloride solution is 1.5%~3.0%. The prepared slow-release granule has a cumulative
release time of over 90 hours in
distilled water, with no obvious burst release phenomenon. Pot experiments show that it maintains a continuous
control effect on eggplant thrips for 7 days after application, which is superior to conventional spraying treatment. This invention has a simple preparation process, is
environmentally friendly, and has excellent slow-release performance, making it suitable for green control of agricultural pests.