2020 Volume 102 Issue 4 Pages 270-276
In order to strengthen the system for increasing the production of male sterile cedar seedlings, we worked with people involved in paddy rice agriculture to hydroponically cultivate container seedlings using fallow fields. After constructing a nursery pool with a depth of about 5 cm in a fallow rice paddy with running irrigation water, we grew two-year-old container seedlings in the pool from May to October. We found the survival rate to be high, at about 98％, and the amount of growth was more than of seedlings grown using conventional greenhouse cultivation. We performed such seedling raising tests using fallow rice fields in both coastal and mountains area and found that plants grew well in both situations, leading us to believe that this cultivation method could be used in a wide range of areas where there are paddy fields. The survival rate and growth rate of seedlings cultivated hydroponically were no different from those of seedlings cultivated in conventional greenhouses when planted to the reforestation area. Based on these facts, we believe this cultivation technique, which consists simply of immersing container seedlings in flooded fallow rice fields, to be a labor-saving and low-cost method of raising seedlings because it does not require the use of a greenhouse or an automatic watering device.
