ESP-SMT Smart Modular Control System79Applying the “Cycle and Soak” PrincipleIn most soil types, you would not want to run the zone’sirrigation system for one hour in duration as this wouldmost likely cause significant water loss through runoff.Based on the soil type and degree of slope informationentered into the controller for the zone, the ESP-SMTcontroller will determine the maximum “cycle” time andminimum “soak” time required to irrigate without runoff.These prescribed cycle and soak times are based onthe Water Intake rate of the soil type as identified in thefollowing tables:Soil Type or Class Basic Intake RateSoil Type or Class Basic Intake Rate(inches per hour)Sand 0.60”Loamy Sand 0.50”Sandy Loam 0.40”Loam 0.35”Clay Loam 0.20”Silty Clay 0.15”Clay 0.10”This process would continue on a daily basis as shown isthe table below:Illustrative Scheduling ExampleDay ET/Day EffectiveRainNet WaterReq’tAccumula-ted WaterReq’tIrrigationEvent1 0.18” 0.00” 0.18” 0.18” ---2 0.16” 0.00” 0.16” 0.34” ---3 0.16” 0.16” 0.00” 0.34” ---4 0.18” 0.00” 0.18” 0.52” 0.53”5 0.14” 0.00” 0.14” 0.13” ---6 0.13” 0.10” 0.03” 0.16” ---7 0.15” 0.11” 0.04” 0.20” ---8 0.14” 0.00” 0.14” 0.34” ---9 0.11” 0.00” 0.11” 0.45” ---10 0.16” 0.00” 0.16” 0.61” 0.60”11 0.12” 0.00” 0.12” 0.13” ---12 0.12” 0.00” 0.12” 0.25” ---In this example the irrigation schedule for the zone would be:Day 4 - 60 minutes (Cycle 1 = 30 minutes & Cycle 2 = 30 minutes)Day 10 – 68 minutes (Cycle 1 = 30 minutes, Cycle 2 = 30 minutes,Cycle 3 = 8 minutes).
