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

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

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

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

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

Monitoring Design

Background and Test Period Soil Moisture and Water Table

Evaluation Period Soil Moisture and Water Table

Total water use 36% saving of total water use

Groundwater P

Groundwater NO3

Fruit Weight

Waterborne disease-Phytophthora

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

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