Soil Moisture Monitoring Using Wireless Sensor Network Ruixiu

Soil Moisture Monitoring Using Wireless Sensor Network Ruixiu Sui USDA-ARS Crop Production Systems Research Unit Stoneville, Mississippi 18 th World Congress of CIGR Beijing, China September 16 -19, 2014

INTRODUCTION • • • Mid-South of USA Major crop production Area Annual Precipitation: 130 cm Irrigated Hot and Less rainfall in summer Supplemental irrigation needed Non-Irrigated

INTRODUCTION • Uncertainty in the amount and timing of rainfall is a serious risk to producers in the Mid-South • Producers have become increasingly reliant on irrigation, but very few use any irrigation scheduling aids • Timely and accurate determination of soil water status and weather conditions are essential to irrigation scheduling

INTRODUCTION Mid-South Region

INTRODUCTION • Irrigation scheduling methods – Weather-based -- schedule irrigation based on the amount of water lost by plant ET and the amount of effective rainfall and irrigation water entering into the plant root zone. – Soil moisture-based -- measure soil moisture levels in the plant root zone and apply water if there is water shortage for plants – Plant-based -- directly detect plant responses to water stress and initialize irrigation as plants indicate suffering from water stress.

INTRODUCTION • Soil moisture measurement required for soilmoisture-based irrigation scheduling • Sensor technologies available for measuring soil moisture -- neutron probes, electromagnetic (EM) sensors (capacitance, TDR, resistance, . . ) • Wireless sensor networks offer capability of providing continuous, real-time, in-situ measurements under a variety of operating conditions

OBJECTIVES • The goal of this research is to develop improved irrigation application and scheduling techniques for humid regions • Specific objective is to develop wireless sensor network (WSN) for monitoring soil water status and collecting weather data for irrigation applications

Wireless Sensor Network 6” 12” 24” Point Area Data Logger & Wireless modem Access Data online

Wireless Sensor Network Em 50 R Em 50 G EC-5 5 TM Wireless Data Logger Frequency: 900 MHz Input: 5 Channels Storage: 1 M Power: 5 AA Bat. Data Station Data logger Wireless Modem Data Station receives and stores data from Em 50 R loggers; Em 50 G cellular data logger; Modem transmits data online via cellular network

Weather Sensors • • • Rain gauge sensor Radiation sensor Temperature sensor Humidity sensor Wind speed & direction sensors Data logger Solar panel for power supply 10 -ft Tower Software package

Sensor Installation • Installed sensors and loggers in multiple locations in cotton, corn, soybean fields • 3 -4 sensors each location in 15, 30, 46 cm depths • Sensor models: EC-5, 5 TM, MPS-2 • Soil moisture measured 24/7 at one hour interval

Sensor Installation • Soil sampler • Gas-powered auger 2. Put in bracket • Dig a hole • Insert the sensors Horizontally • 3 MC sensors/hole Data Station

Issue for Field Operation Required to lay down the logger pole for applying Chemicals

Antenna Mounts Developed

Antenna Mounts Test Click on picture to play video

Data Logger Installation EM 50 R Logger 2. Put in bracket EM 50 G Logger Data Station

WSN in Soybean Field

Received Signal Strength Indication (RSSI) Date 14 -May-12 21 -May-12 28 -May-12 4 -Jun-12 11 -Jun-12 18 -Jun-12 25 -Jun-12 2 -Jul-12 9 -Jul-12 16 -Jul-12 23 -Jul-12 30 -Jul-12 6 -Aug-12 13 -Aug-12 20 -Aug-12 27 -Aug-12 3 -Sep-12 10 -Sep-12 Cotton Field (Logger 18 -50 G) RSSI Attempts 19 1 20 1 19 2 18 1 17 1 14 1 10 1 11 1 13 1 10 1 15 1 16 1 17 1 Corn Field (Logger 19 -50 G) RSSI Attempts 14 1 10 1 11 1 9 1 9 2 10 1 8 1 9 1 11 1 9 1 NA NA Soybean Field (Logger 20 -50 G) RSSI Attempts NA NA NA 10 1 13 1 12 1 10 1 11 1 10 1 13 1 12 1 16 1 20 1 NA NA

RSSI in 2013 Logger Location Crop 5/1/13 – 5/15/13 5/16/13 5/31/13 6/15/13 6/30/13 7/11/13 1 Cotton NA* 8 12 11 20 2 Cotton NA 17 19 19 18 3 Cotton NA 19 20 20 19 4 Cotton NA 19 18 20 20 5 Cotton NA 20 19 19 17 6 Cotton NA 19 16 17 15 7 Corn 77 72 57 55 52 8 Corn 71 64 40 54 55 9 Corn 70 62 33 25 18 10 Corn 66 59 25 29 30 11 Corn 62 43 29 12 12 12 Soybean NA* 70 77 77 76 13 Soybean NA* 62 63 61 70 14 Soybean NA* 67 67 64 60 15 Soybean NA* 63 64 62 59 16 Soybean NA* 60 60 56 50

Downloading Data Online

Soil Moisture Data From WSN

Soil Moisture Data From WSN

• WSN collected data for 3 years • Data have been used for irrigation scheduling • Performed well in general • Thunderstorms could interrupt data transmission • Animals (wild dog, pig, turtles) might chew cables Variable Rate Irrigation in Soybeans Irrigation Research in Cotton Corn Research Field

SUMMARY • Wireless sensor network was built and deployed for monitoring soil moisture and collecting weather data for 3 years. The WSN is capable of automatically measuring and wirelessly transferring soil moisture and weather data online, enabling remote access of the data; • An antenna mount was developed for field use with wireless data loggers; • Evaluated for 3 years; The WSN performed well; • Soil moisture data and weather data collected by the WSN has been used for irrigation research.

Acknowledgements This project was partially supported by Cotton Inc. Thank Mr. Jonnie Baggard for his assistance in this project. Disclaimer Mention of a commercial product is solely for the purpose of providing specific information and should not be construed as a product endorsement by the authors or the institutions with which the authors are affiliated.

Ruixiu Sui, Ph. D. Research Agricultural Engineer, Lead Scientist United States Department of Agriculture (USDA) Agricultural Research Service (ARS) Crop Production Systems Research Unit 141 Experiment Station Road Stoneville, MS 38776 Email: ruixiu. sui@ars. usda. gov http: //www. ars. usda. gov/msa/jwdsrc/cpsru/sui