Here is a proof-of-concept system for fertigation monitoring. It has been quick to get up and running with off-the-shelf components and software. Limited by the accuracy of inexpensive sensors… working on optical sensors that deliver lab-grade resolution at farm supply price. Comments welcome on the attached overview.

1. Fertigation Monitoring
IoT Proof of Concept
Val King | Salinas, CA | Fall 2017

2. Problem Statement
• AG Order 3.0 and future compliance
– Measurement and record keeping
• Bi-annual irrigation well nitrate test
• Nitrogen application log
• Drain water nitrate monitoring
• Fertilizer expense & effectiveness
– Inconsistent fertigation rate & uniformity
Val King | Salinas, CA | Fall 2017

3. Proof of Concept – Fertigation Monitor
• IoT computer
– Waspmote real-time compute engine
• Development environment & sample code
– Compatible IoT Arduino and Raspberry Pi ecosystems
• Connectivity
– WiFi, 4G and private mesh networks
• Ion-selective electrode sensors
– Ca2+, Cl-, K+, Mg2+, Na+, NO2
-, NO3
-, NH4
+
• Irrigation sampling tank
– Simple design with off-the-shelf components
Val King | Salinas, CA | Fall 2017

4. Fertigation Monitoring - IoT Platform
Val King | Salinas, CA | Fall 2017

5. Fertigation Monitoring - Sampling Tank
Val King | Salinas, CA | Fall 2017

6. Fertigation Monitoring - Application
Val King | Salinas, CA | Fall 2017

7. Nitrate Monitoring - Application
Val King | Salinas, CA | Fall 2017

8. Fertigation Monitoring - Integrated System
• Self-contained monitor system
– Solar powered & Ag hardened
– Pressure or remote ON
– Real-time data collection
• Stainless steel sampling tank
– Auto flush, fill and drain
• Scalability
– Fertigation uniformity
– Variable rate control
– Field sensor base station
– Denitrification controller
Val King | Salinas, CA | Fall 2017

9. Fertigation Monitoring – Concept Review
• Strengths
– Low cost
• Plentiful off-the-shelf building blocks
• Ecosystem of software developers
– Quick development cycle
• Ranch specific and new technologies
• Limitations
– Sensor accuracy and calibration
• Developing low-cost optical with lab-grade resolution
– Supplier and integrator marketplace not developed
• Educational and entrepreneurial opportunities
Val King | Salinas, CA | Fall 2017