PROBLEM TO BE SOLVED: To provide a soil improving material causing no growth obstruction, excellent in water retention and fertilizer retaining ability at a low cost and to provide seedling compost using the soil improving material. SOLUTION: This soil improving material comprises a woody loose fibrous material obtained by subjecting raw material of wood to steam explosion treatment. The volume weight (g/ml) of the woody fibrous material is 0.4-1 time of that (g/ml) of the raw material of wood. The maximum water-holding capacity (ml/100 ml) of the woody fibrous material is 1-1.6 time(s) of that (g/100 ml) of the raw material of wood. COPYRIGHT: (C)2006,JPO&NCIPI
