The　high　cost　and　difficulty　in　sustainability　have　hindered　the　wide　application　of　the　general　synthetic　resins　in　the　controlled-release　fertilizers　(CRF).　Here,　the　degradable　castor　oil-based　polyurethane　(PU)　was　filled　by　the　natural　pyrophyllite　(PY)　powders,　which　were　pre-modified　with　few　amount　(＜0.5　%)　of　NDZ-201　coupling　agent　though　a　simple　and　economic　mechanochemical　method.　Furthermore,　the　composite　materials　of　PU　and　the　modified　PY　(MPY/PU)　with　enhanced　comprehensive　properties　were　prepared　and　applied　in　CRF.　Moreover,　the　release　behaviors　of　the　coated　fertilizers　were　investigated　while　tuning　the　addition　amount　of　modifier　or　the　filling　amount　of　MPY,　and　it　was　confirmed　that　the　release　performance　was　highly　depended　on　the　hydrophobic　and　mechanical　properties　of　the　composite　coating.　As　a　result,　the　best　optimized　MPY/PU　coating　exhibited　significantly　superior　performance　to　the　pure　PU　materials,　and　the　duration　of　80　%　nitrogen　release　was　more　than　40　days.　This　confirms　that　the　MPY/PU　composite　is　a　promising　coating　material　for　the　CRF　granules.(c)　2022　The　Author(s).　Published　by　Elsevier　B.V.　on　behalf　of　King　Saud　University.　This　is　an　open　access　article　under　the　CC　BY-NC-ND　license　(http://creativecommons.org/licenses/by-nc-nd/4.0/).