Abstract
The long-term sustainability of commercial vegetable production requires increased fertilizer and irrigation efficiency. Vegetables growers recognized as leaders in fertilizer and drip irrigation management in North Florida were selected to demonstrate how irrigation and fertilizer management are linked together and how management may prevent water movement below the root zone of several vegetable crops, all grown with plasticulture. Colored dye was injected into the irrigation water in existing drip irrigation systems periodically during the growing season. Subsequently, cross sections of the beds were excavated to observe the soil profile to determine the depth of dye penetration. Similar results were found at all locations: water movement was greater early in the season (1 to 5 weeks after establishment) and the dye moved below the root zone (20 to 30 inches deep). The vertical movement of the dye was less on a loamy soil with an impermeable layer than on the deep sandy soils. The uniformity of water movement decreased as depth increased. Overall, these data show that some leaching is likely to occur on light-textured soils, even when UF/IFAS recommended practices are followed. Educational efforts should focus on fertigation management during the 2-3 weeks after crop establishment. Based on their involvement with this project, the cooperators refined their current fertigation practices as well as considered other future changes to improve their management of water and nutrients. This project shows that vegetables growers are more likely to try and adopt sustainable practices when they actively participate in the educational process than when production changes are mandated through legislation.
