1. Department of Agricultural and Biological Engineering
Evaluation of Wireless Soil Moisture Measurement Systems with regards to water quantity and quality
Sanjay Shukla
Chambal Pandey
Department of Agricultural and Biological Engineering

2. Introduction Florida ranks 2nd in vegetable production in US
Seepage irrigation is common - upflux from the shallow water table (~45 cm)
Visual observation and/or hand-feel methods result in under/over irrigation
Conventional practice-high water table
Wastage of water, more runoff, and less rainfall storage
Nutrient leaching to groundwater
Solutions
Soil moisture based water table management

3. Objectives
Collect background soil moisture data at a vegetable farm in South Florida.
Evaluate the effects of wireless soil moisture based water table management practice on water use, water quantity and crop yield

4. Experimental Details Study area = 6.5 ha
Eight fields (each: 274 m x 31 m )
Subsurface irrigation and drainage system (SID)
Study periods:
Sep, 02 - May 03
Sep, 03 - Apr 04
Soil: Myakka sand
Eggplant and Pepper

5. Data Collection Hydrologic Nutrients Soil moisture Water table
Wireless Capacitance probe
Data transmission from field to grower’s office
Water table
Rainfall
Irrigation
Nutrients
Groundwater
Soil

6. Monitoring Design

7. Background and Test Period Soil Moisture and Water Table

8. Evaluation Period Soil Moisture and Water Table

9. Total water use
36% saving of total water use

10. Groundwater P

11. Groundwater NO3

12. Fruit Weight

13. Waterborne disease-Phytophthora

14. Summary Soil moisture based water table management saved 36% of water.
50% less runoff
reduced nitrate leaching to the groundwater
better crop performance
overall better or equal yield
100% more yield compared to the conventional side due to crop disease

15. Conclusions
Considerable reduction in irrigation water use by soil moisture based water table management compared to the conventional irrigation management.
Soil moisture based water table management increased available soil water storage resulting in less frequent drainage and runoff events
Soil moisture based water table management reduced nutrient leaching