Abstract: The plants above are grown in a cultivation container from seeds or young plants to the condition of them enabling to harvest. The cultivation containers are transfered in sequence to each cultivation area from the cultivation starting region of the cultivation factory to the cultivation ending region every day or every cultivation hour. During the transfer of the plant, the plant to be cultivated in the cultivation containers are supplied with water by means of a water supply apparatus of cultivation liquid.Application of light is restricted to the plant by a cover until the cultivation ending zone and light is applied to the plant at ending of the cultivation to grow them. Consequently, good plant and vegetables are obtained.The seeds mentioned above are scattered in the cultivation containers through a seed scattering apparatus. The seed scattering apparatus is provided with a scale for measuring a unit volume of the seeds.

Abstract: A delay time compensation circuit includes a pair of first and second sensing devices having different time constant values. The outputs from the sensing devices are each differentiated and at the same time compared to provide a difference signal. Both differentiated and difference signals are processed into an output which represents a value to compensate for errors resulting from the first-order time lag of the sensing devices. The compensating output is added to the output from the first sensing device.