|Performance of the intelligent irrigation control system under realistic conditions :
Avocado orchard Yechiam
Western galil - Clay soil
Deeper layers only
The numbers in each parenthesis under each irrigation event represant the sensor number at the final wetting depth, ZF and the sensor numbers to stop irrigation, ZI . The indicated changes in the sensor numbers represanting ZI are between 3 and 4, because the 40 cm layer was fluctuating between the state of being wetted or not being wetted by the drainage front. The state of wetting resulted in a deeper ZI value and vice versa. These changes indicate that the control alogarithems were at work. The end result was that the soil layer 46 cm deep was not wetted by the drainage front.
Revivim Olive grove
Southern Negev – Sandy loess soil
Final wetted depth – M 4 - 28 cm
Stopping depths - M 2,3 – 16,22 cm
Soil layer at sensor M 4 – 28 cm – Sensor resistence and therefor soil water content are practically constant with time .
Lower soil depths M 5,6,7 – 34,40,46 cm – Sensor resistence and soil water content are constant with time.Thus, there is no leakage of irrigation water into these layers.
Active rooting depth 4 – 22 cm .
Irrigation intervals 2 -3 days.
Caesarrea Golf Course
Coastal area sandy soil
Deeper soil layers
Final wetting depth – M 4 – 28 cm
Stopping depth – M 1,2 – 10 , 16 cm
Soil layer at final wetted depth - M4 – 28 cm – Some fluctuations in sensor resistence and soil water content. A general trend of drying is apparent.
Soil layer at - M5 – 34 cm depth - Sensor resistence and soil water content are practically stable with slow tendency of drying .
Irrigation intervals 2 days .
Stopping irrigation at – M2 – 10 cm depth – resulted in a tendency of the wetted depth layer to dry, stopping irrigation at layer - M3 – 16 cm and doubling irrigation amounts (duration) prevents tendency of – M4 – 28 cm – layer to dry.
Active rooting layers – M 1-4 – 4-28 cm .
Considerable drainage of irrigation water to layers M2-4 – 16 – 28 cm.