Table 4.

CRFs coating from other organic materials.

Other Organic Materials
Material	Modifier	Research Findings	Release Duration a	References
Biochar	Bentonite, sepiolite	Good urea sorption capability by biochar and mineral binder to slow down the release.	30 days	[31,86]
Rosin Adduct	Maleic anhydride	The effective barrier for urea release due to the covalent bond between maleic anhydride and urea. Works effectively under different soil texture.	4 days b	[29]

^a Time required to reach 75% release; ^b Time required to release 45% and reached plateau.