This study was conducted to elucidate the effects of fertilization level on the growth of Cryptomeria japonica container seedlings. In a basic fertilizer test, seedlings were grown under three fertilization conditions using the slow-release fertilizer A (N-P-K＝12-8-10) at 5-6, 10-12, or 20-24 g/L. Seedling height increased with increasing amounts of fertilizer added, although no differences were observed between the 10-12 and 20-24 g/L doses. In the additional fertilizer test, the effects on seedling growth were compared between three concentrations of slow-release fertilizers B (10-18-15) and C (6-9-9) at 1.5, 3.0, or 4.5 g/seedling, and a liquid fertilizer. Additional treatment with 4.5 g of fertilizer B produced the greatest increase in seedling growth, particularly diameter. Seedlings were raised under optimal conditions of base fertilization treatment (20 g of fertilizer A, 40 g of leaf mold and 4 g of magnesium lime per 1 L of soil) and additional fertilization treatment (4.5 g of fertilizer B and 0.9 g of magnesium lime per plant); this treatment produced seedlings with an average size of 36.2 cm in height and 4.8 mm in diameter one year after sowing. From this experiment, the 69％ of container seedlings grew up to reach the Japanese Forestry Agency’s 5th standard size even within one growing period, although the period for bare-root seedlings needs two years in the Japanese Kanto region. Therefore, our results demonstrate a reduction of the growth period of Cryptomeria japonica through the efficient propagation of container seedlings supplemented with the application of slow-release fertilizers.

We estimated the economic ripple impact of utilizing locally supplied wood products from Saitama prefecture on a public building, Sugito Kindergarten-Nursery School. We used the Saitama prefecture Input-Output Table for estimations in two scenarios: (1) A basic scenario conforming to the actual distribution route including the outflow of prefectural roundwood to other prefectural sawmills and the inflow from other prefectural sawmills to Saitama; (2) A comparative scenario assuming that all production and distribution of roundwood and lumber are completed within Saitama. The results of estimation produced a total induced production value and induced production coefficient of 35.101 million yen and 1.09, respectively, in the basic scenario, and 44.9 million yen and 1.39, respectively, in the comparative scenario, indicating a greater economic ripple impact with the comparative scenario. It shows that promoting the consumption of local wood products on public buildings could be effective both for vitalizing the forestry and wood processing industry, and for the prefectural economy. Furthermore, some sawmills in Saitama will acquire JAS-certified for manufacturing lumbers possessing rectangle cross section for beam, this effort may help to increase the consumption of local structural lumbers on public buildings. The economic ripple impact of utilizing local wood products on public buildings will increase in the future.

We investigated early performance of three kinds of sugi cuttings (1-year- and current-year-old containerized, and current-year-old bare-root) subjected to different watering regimes (everyday watering (EW), every 8 days watering (8W), and non-watering (NW)) after summer planting in green house. We also compared plant part mass between dead and survived cuttings after current growing season. In EW treatment, all containerized cuttings survived, while a half of bare-root cuttings died. In 8W, 33％ of 1-year-old and 42％ of current-year-old containerized cutting survived, but all bare-root cuttings died within three months after planting. NW killed all cuttings within 1.5 month. Cuttings planted in the field for a reference showed better tree vigor in cultivated soil than in uncultivated, and the highest survival in 1-year-old containerized cuttings, followed by current-year-old containerized, and bare-root cuttings. These results demonstrated experimentally that containerized cuttings have a certain advantage in establishing under severe drought condition than bare-root cuttings. Survived cuttings had greater root mass than dead cuttings; the difference in root mass was greater than in branch mass. Among current-year-old cuttings, containerized cuttings survived under less watering regime (8W) with a range of root mass which was equivalent to that of bare-root cuttings dead under more watering regime (EW). We concluded these results that a certain level of root growth of each stock type raised the survival of cuttings, and that the soil medium of containerized cuttings has a role of supporting their survival with smaller amount of roots and/or under severe drought.

We review the current status of the wood products under the framework of Geographical Indications (GIs) in Japan and also in international contexts. In concrete terms, Iwate Charcoal was the first wood related products registered under the current Japanese system. We analyzed the motives, application process, difficulties including the description of charcoal quality at the application phase and agreement of quality control.

In order to clarify the factors that restrict seed germination in production of containerized seedlings of Cryptomeria japonica, we studied the cause of un-germinating seed in container pots and the pathogenicity of fungi isolated from rotted seeds. Un-germinating seeds (95 seeds) at two months after seeding were categorized into healthy (30.5％), rotted by fungi (34.7％) and insect herbivory (8.4％), empty (21.1％) and sterile (5.3％). Fusarium oxysporum was isolated from rotted seeds and has pathogenicity of seed rot by our inoculation test. This suggests that seed rot by a fungal pathogen causes restricting seed germination in production of containerized seedlings.