Irrigation Automation and Soil Moisture Monitoring Reduces Water Usage, Energy costs, and Tree Disease
Location: Woodland, California
Crop Grown: 250 Acres of Walnuts
Solutions: Valve Control, Pump Control, Soil Moisture Monitoring, weather and climate, camera
“I found RanchMaster to be almost flawless in its operation. I particularly enjoy being [able] to adjust my irrigation schedule anytime from anywhere. The system has saved me money, time and water as well as improved the health of my orchard.”
Bob Payne, Owner
Bob Payne and his brother have been farming a wide variety of crops, including melons, tomatoes, and nuts, for over twenty-five years. One of their ranches is a 250 acre block of walnuts in the Woodland area of the Sacramento Valley. In 2012, a new well and variable frequency drive pump was installed in the orchard to improve the water supply and irrigation.
There were several issues with the new pump and irrigation system. The pump was on AG 1-B electricity rate schedule, which charged a premium rate for electricity used during peak hours. Irrigating in the evenings and at night when rates and evaporation were at their lowest was unfeasible. The manual system also made switching to shorter irrigation sets impractical. One adverse impact of using long irrigation sets was overwatering, which not only wasted water, but also result in root rot due due to the soil borne phytophthora fungus. This lowered yield and resulted in a number of trees dying. Bob was in contact with Zach Sheely of Azcal Management Company in Lemoore, CA. Zach had implemented, in several blocks of pistachios, a RanchMaster wireless system for VFD and valve control as well as soil moisture monitoring. He was able to increase his yields and lower water consumption by implementing pulse irrigation driven by maintaining soil moisture within an optimal band. Based on Zach’s recommendation, Bob decided to pursue a similar solution for his walnut orchard.
RanchMaster Wireless Solution
First, the valves needed to be upgraded with DC latching solenoids. The 250 acre block was divided into 6 irrigation zones (fields), each with a 5′ soil moisture capacitance probe in a location representative of the soils. Each zone had 2-3 valves and pressure gauges monitored and controlled by RS300 wireless nodes in communication with a central RM210 base station, which provided the gateway to the Ranch System online software via the cellular data network. The base station also did double duty by hosting a full set of weather sensors. The VFD pump was controlled by another node and a flow meter recorded total water usage. Finally, a remote camera provided visual monitoring of the tree canopy.
Right away, Bob was able to start evening and night irrigation. In addition, he changed to a three set schedule where zones were watered for 6 hours at a time instead of 18. He looked at the soil profile in the various probe locations and adjusted the schedule according to actual soil conditions and avoid saturation. In the course of one season, he was able to reduce the amount of water he applied to about 20%. Due to pumping less and pumping at off peak hours, his power bill was significantly lower. Perhaps most importantly, orchard health improved; yields increased and there was a marked decline in tree mortality.