To strengthen the production system for pollen-free cedar cuttings, management techniques were developed to utilize fallow fields as cuttings orchards for pollen-free cedar. A soil diagnosis of the fallow fields was conducted prior to planting the scion trees, revealing no significant issues, with a groundwater level below 50 cm and a cultivated soil depth of approximately 20 cm. As a result, 491 scion trees were planted at the test site, achieving a high survival rate of 98.8%. Additionally, biannual fertilization during the growth period of the scion trees led to 83.1% of the trees reaching a height of 2.3 meters or more the standard for pruning-by the third growth season. Based on these findings, it was considered that by maintaining the groundwater level of the fallow paddy field at 50 cm or lower, ensuring a cultivated soil depth of approximately 20 cm, and applying appropriate fertilization, it would become possible to harvest propagation materials from the seed orchard established in the fallow paddy field approximately four years after planting.

In order to strengthen the production system for pollen-free cedar cuttings, I developed a labor-saving seedling production technique that utilizes fallow rice fields for hydroponic cultivation of containerized cuttings. After creating seedling pools with a water depth of approximately 5 cm in fallow fields using agricultural water for continuous flow, the containerized cuttings were cultivated by hydroponics. When cultivation was performed inside tunnels covered with shade nets, the survival rate of the cuttings was high, exceeding 90%. Additionally, by adjusting the cutting length to 30 cm and mixing a basal fertilizer at a concentration of 10 g/L into the cultivation soil, the rooted cuttings exhibited good growth, achieving an average height of 37.3 ± 6.9 cm per growth season and a rooted cuttings yield rate of 55.0%.These results suggest that the cultivation method used in this study is simple, as it only requires submerging containers with direct-planted cuttings into the seedling pools. Furthermore, it does not require greenhouses or automated irrigation systems, making it a labor-saving and low-cost method for rooted cuttings production.