Real-time soil moisture control for very high frequency drip irrigation in olive groves

CAPRARO FLAVIO; TOSETTI SANTIAGO; VITA FACUNDO

ACTA HORTICULTURAE

International Society for Horticultural Science

Año: 2011 vol. 888 p. 239 - 246

0567-7572

This article presents the development and field implementation of a PC-based drip irrigation feedback controller installed in olive groves. Capacitive moisture sensors were used to know the moisture in the olive roots. Twelve sensors were distributed in the grove and communicated with a remote PC through an RS-485 network. A model-based predictive control (MBPC) algorithm determines the amount of water required for reaching and maintaining over time the moisture reference level. The control algorithm integrates several tasks such as: the management of drip irrigation restrictions, the attention priorities, the irrigation sequences, the synchronizations between areas, and the water optimization. The moisture level is kept close to the reference by means of very high frequency irrigation. The controller calculates the opening/closing time for each valve of the drip irrigation system. A Human Machine Interface (HMI) was also designed to configure the parameters of the process, to show the process information in real time and to present the historical information. Trials were carried out in the province of San Juan, Argentina, in an intensive experimental olive (‘Arbequina’) orchard