A seed coating agent used for coating the surfaces of seeds contains iron powder and a binding material. In said iron powder, the percentage by mass of iron powder particles having a particle size smaller than or equal to 63 µm to the total mass of said iron powder is from 0% to 75% inclusive, the percentage by mass of iron powder particles having a particle size larger than 63 µm and smaller than or equal to 150 µm to the total mass of said iron powder is from 25% to 100% inclusive, and the percentage by mass of iron powder particles having a particle size larger than 150 µm to the total mass of said iron powder is from 0% to 50% inclusive. The average particle size of said binding material is between 1 and 150 µm. Thus, it is possible to achieve a coating that causes only a small amount of iron powder to fall off not only during the seeding process but also during the transportation process.
