PROBLEM TO BE SOLVED: To reduce the water content of seeds to about 7 to 10% in a short time as much as possible while avoiding the occurrence of mechanical decapitation and cracking. SOLUTION: Between a hot air supply step of supplying high temperature hot air having a hot air temperature of 60 ° C. or higher and lower than 80 ° C. to the ventilation drying section and a hot air supply step for a certain period of time from the start of drying in order to accelerate the temperature rise of seeds. Is a circulation amount control step of controlling the circulation amount so that the amount of seeds passing from the grain tank to the ventilation drying part is less than a predetermined amount and the residence time of the seeds in the ventilation drying part is longer than a predetermined amount. And the hot air temperature control step of detecting the grain temperature of the seed by the grain temperature detection unit provided in the grain tank and lowering the hot air temperature supplied by the high temperature hot air supply step when the grain temperature reaches a certain temperature. Prepared. [Selection diagram] Fig. 5【課題】 機械的な脱ぷ粒及び割れ粒の発生を避け、できるだけ短時間で種子の水分量を７～１０％程度に低下させる。【解決手段】 種子の温度上昇を早めるために乾燥開始からの一定時間は熱風温度が６０℃以上８０℃未満の高温の熱風を前記通風乾燥部に供給する熱風供給工程と、熱風供給工程の間は前記穀物タンクから前記通風乾燥部に通過する種子の量を所定よりも少なくし、かつ、前記通風乾燥部における前記種子の滞留時間を所定よりも長くするよう循環量を制御する循環量制御工程と、前記穀物タンクに設けた穀温検出部により種子の穀温を検出し、当該穀温が一定温度に到達したら前記高温熱風供給工程により供給されている熱風温度を下げる熱風温度制御工程とを備えた。【選択図】図５
