A MODIFIED TENSIOMETER FOR IRRIGATION CONTROL IN POTTED ORNAMENTAL PRODUCTION

A modified tensiometer is presented. This device can be used with clos ed-loop control systems to control irrigation. The device consists of a porous plate placed at the bottom of a cylinder with a pressure tran sducer to measure matric potential. The device avoids problems typical of the use of conventional tensiometers in soil-less ornamental crop production. The modified tensiometer provided accurate results of matr ic potential over an extended time. The pressure readings were not aff ected when the modified tensiometer was handled. The problem of loss o f contact due to soil-less media aging and unintentional movement of t he media common with conventional tensiometers was avoided.