3rd UF Water Institute Symposium Abstract

Submitter's Name Aparna Gazula
Session Name Posters - Efficacy of Nutrient Source Control Strategies 2
Category Efficacy of nutrient source control strategies
Poster Number 9
Author(s) Aparna Gazula,  UF/IFAS Alachua County Extension (Presenting Author)
  Robert Hochmuth,  UF/IFAS Suwannee Extension
  Eric Simonne, UF/IFAS Extension
  The Blue Dye Doesn’t Lie: On Farm Demonstration of Water Movement in Plastic Mulched Beds.
  Given the low water holding capacity of Florida’s coarse textured soils the vegetable growers using drip irrigation oftentimes over-irrigate to maintain adequate moisture levels within the crop root zone. N-P-K fertilizers are highly water soluble, and as growers mismanage the irrigation water application, they generally tend to over-fertigate to compensate for the loss of nutrients from the plant root zone. These practices of over irrigating/fertigating may not only increase leaching of nutrients into the ground water, but also increase crop production costs. Therefore, to demonstrate visually the wetting pattern of drip irrigation water in Florida’s sandy soils, soluble blue dye (Terramark SPI High Concentrate, ProSource One, Memphis, TN) was injected into the drip tube of plastic mulched beds at 1:49 (v:v) dye-water dilution rate for approximately 10-minutes. The dye injection was done with a portable battery operated pump prior to an irrigation cycle. At the end of the irrigation cycle, transverse and longitudinal sections of the mulched bed were carefully dug with a shovel. Each hole was dug deep enough to see the bottom of the dye. The blue dye patterns in the soil definitively demonstrate water movement in plastic mulched beds. The depth and width of the wetted front varies with soil type, length of irrigation and flow rate. Several on-farm demonstrations presented throughout the Suwannee Valley area have shown that vegetable growers are more likely to try and adopt Best Management Practices when they actively participate in the educational process than when production changes are mandated through legislation.