Provided is a means for achieving an excellent plant growth promoting effect of a 5-aminolevulinic acid easily even with a few applications thereof. A solid fertilizer comprising the following components (A) and (B): (A) a 5-aminolevulinic acid represented by the following general formula (I): €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒR 2 R 1 NCH 2 COCH 2 CH 2 COR 3 €ƒ€ƒ€ƒ€ƒ€ƒ(I) wherein R 1 and R 2 are each independently a hydrogen atom, an alkyl group, an acyl group, an alkoxycarbonyl group, an aryl group, or an aralkyl group and R 3 is a hydroxy group, an alkoxy group, an acyloxy group, an alkoxycarbonyloxy group, an aryloxy group, an aralkyloxy group or an amino group, a derivative thereof or a salt of the acid or the derivative, and (B) a solid fertilizer raw material.
