Water and nutrient savings with soil moisture sensors

Soil moisture sensors help Suwannee Valley growers manage irrigation
Soil Moisture Sensors (or SMS) are a precision agriculture technology on the rise in North Florida. With the help of a grower survey, the Suwannee Valley Agricultural Extension Center evaluated the advantages and challenges of their use over the summer of 2017. Though soil moisture sensors have been around for over a decade (in simpler forms), the difference is that new equipment now provides 24-hour, multi-depth sensing that can help guide irrigation timing and amounts. Overwhelmingly, growers who attended UF/IFAS workshops and field days shared positive comments on the productive role SMS play in their field management, especially for irrigation scheduling.

Our survey found that a record 600+ SMS sensors are in operation in the region, representing almost 85,000 acres served by eight vendors in North Florida. Collectively, the survey participants are using 125 probes (~21% of all probes in the SRWMD) and collectively farm around 17,000 acres (~12% of SRWMD irrigated acres). Of the nine growers interviewed, eight out of nine (89%) indicated they have changed how they irrigate, 89% saw savings in water, fuel, fertilizer, or electricity, and 78% showed labor reductions. One grower commented “I now have piece of mind, to worry less about watering my crops”. Another said probes “take the guesswork out” and figures he is saving 50,000 gallons of water each day. Gaining confidence with a few growers is an important step, considering the growing need for water use efficiency (with greater water demand) across the 142,000 acres which are irrigated in the Suwannee valley.

Benefits varied for each farm, but most noted that continuous data availability on mobile devices allows for closer management of fields, especially geographically distant ones. It is evident by the survey, that soil moisture sensors are now widely used in the area, and they are helping growers manage irrigation more efficiently. Long-term goals include quantifying the impact Soil Moisture Sensors have on yields, crop quality, water conservation, and nutrient management. One corn grower summarized an important message for the public, “Farmers are doing their best with new technologies, to protect groundwater and producing the best crop with the least inputs”. That’s a good indication, more precision ag will find its way into use.

Do winter cover crops have a place on your farm?
Through UF/IFAS, six on-farm soil improvement demonstrations were started which will collect production data for two years. We interviewed farmers as potential participants and heard positive comments of cover crop use, like “this is what my father did before all the fertilizer sales reps came along”, and “keeping roots and diversity in the system keeps my land productive”. Plenty of articles and science show the benefits of good rotations and cover crops, but our sandy soils and climate make long term investments in the soil a constant struggle. Will they pay off? How quickly can I see yield improvements? With UF/IFAS agent involvement and stronger biological, chemical and physical soil tests to quantify the short-term changes, we hope more farmers will return to this age-old practice and see greater resilience.

With a grant award from the Southern Sustainable Agriculture Research and Education (SSARE) program, the six local farms are now part of a study on soil health and forage quality. They range in size and crops, but all have expressed an interest in committing to sustainable land conservation practices like cover cropping. With farmer input, UF/IFAS agents are testing species adapted to our area to document the benefits they may provide for soil, livestock or summer cash crops. One peanut grower with strong nematode pressure said: “something has to change, and if I don’t do it, we’ll be buying more chemicals and getting deeper in debt”.

Already at this early stage of implementation, we have seen other organizations stepping up to the plate. Our local Suwannee County Conservation District anted up with their own match of $15,000 to expand the number of farms and acres in the study. The Florida Department of Agriculture and Consumer Services Office of Ag Water Policy also realizes how cover crops capture residual nitrogen (to improve water quality) and have started talking about increasing adoption with cost-share reimbursement for seed and equipment. As much is unknown about which species and what management works in north Florida, this project will certainly answer some questions and ask many more.

For more, see:
https://www.researchgate.net/publication/324262914_Soil_Moisture_Sensors_Help_Suwannee_Valley_Growers_Manage_Irrigation

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