Evaluation of Irrigation Threshold and Duration for Tomato Grown in a Silt Loam Soil

Abstract

<jats:p>Soil moisture-based, high-frequency, low-volume (pulsed) irrigation management strategies have saved water while maintaining yields of vegetables grown in coarse textured soils. However, little is known regarding the efficacy of soil moisture-based pulsed irrigation on finer textured soils. Therefore, five tensiometer-based, automated irrigation treatments were tested for tomato (<jats:italic>Solanum lycopersicum</jats:italic>) grown in a Maury silt loam soil in 2009 and 2010 in Lexington, KY. Irrigation treatments consisted of paired-tensiometer systems with on/off setpoints of −30/−10, −30/−25, −45/−10, and −45/40 kPa in both 2009 and 2010 and a single-tensiometer system with setpoints of −35 kPa in 2009 and −40 kPa in 2010. In 2009, the pulsed systems (−30/−25, −45/−40, and −35 kPa) irrigated more frequently but for a shorter duration than non-pulsed systems (−30/−10 and −45/−10 kPa). Soil moisture measurements in 2009 suggested that probes set at a depth of 6 inches were more closely matched to irrigation setpoints than those at 12 inches. In both years, the −45/−40 kPa setpoint treatment used the least amount of water while maintaining total marketable yields that were not significantly different from other treatments. Yields were significantly higher in 2009 than 2010, though atypical air temperatures in 2010 may have been the cause. Leaf water potential and relative water content were measured predawn and midday throughout the growing season in 2009 and 2010. Leaf water potential was not significantly affected by the treatments in either year, though leaf relative water content was affected in 2010. In this trial, an automated, soil moisture-based irrigation system maintained yields and saved water when compared with a non-pulsed irrigation system using similar irrigation setpoints for tomato grown in a silt loam soil.</jats:p>

Comparing a Smartphone Irrigation Scheduling Application with Water Balance and Soil Moisture-based Irrigation Methods: Part I—Plasticulture-grown Tomato

“…The SMS-based irrigation regime was automated using paired-switching tensiometers (model RA 6 inches; Irrometer, Riverside, CA) (Coolong, 2016;Coolong et al, 2011). Plots receiving SMS-based irrigation were controlled independently and each plot had a pair of tensiometers.…”

Evaluation of Shallow Subsurface Drip Irrigation for the Production of Acorn Squash

“…Automated irrigation was managed using paired-switching tensiometers (model RA 12-inch; Irrometer, Riverside, CA) following the method of Coolong et al, 2011b. In brief, one tensiometer functioned to turn on irrigation at the set point reflecting a higher (drier) soil moisture tension, whereas the other turned it off at the set point indicating the lower (wetter) soil moisture tension.…”

“…However, previous reports for tensiometer-based irrigation using surface drip tubing have used tensiometers placed equidistant between plants in a row. Tensiometers were typically placed in the planted row or midway between drip tubing and the planted row at depths of 6 inches (Coolong et al, 2011b;Smajstrla and Locascio, 1996). This suggests that while SDI that is managed with a soil moisturebased system may be more efficient than a time-based system (Zotarelli et al, 2008(Zotarelli et al, , 2009, there are likely key differences in how SUR and SDI respond to irrigation management.…”

Impact of Tillage and Irrigation Management on Bell Pepper (Capsicum annuum L.) Grown in Organic and Conventional Production Systems

“…Each control module was wired to the timer/controller in lieu of a rain gauge to prevent irrigation when soil moisture content was above a predetermined soil water content threshold. Irrigation thresholds were set at 23% VWC (-61 kPa) for well-watered treatments and 19% VWC (-101 kPa) for waterrestricted treatments based on previously conducted research at the site using poblano pepper (C. annuum) and tomato (Solanum lycopersicum L.) (Coolong et al, 2011b(Coolong et al, , 2012. The values chosen reflected reasonable soil moisture levels for an irrigated crop that would be considered well watered and water restricted.…”