Canopy temperature versus soil water pressure head for the prediction of crop water stress

Sensitivity of thermal imaging and infrared thermometry to detect water status changes in Euonymus japonica plants irrigated with saline reclaimed water

“…Many studies have reported the use of thermal imaging and/or infrared thermometry to detect abiotic stresses in diverse field crops: grapevine (Baluja et al, 2012;Fuentes, De Bei, Pech, & Tyerman, 2012), citrus (Ballester, Jim enez-Bello, Castel, & Intrigliolo, 2013; García-Tejero, Dur an-Zuazo, Muriel-Fern andez, & Jim enez-Bocanegra, 2011), persimmon trees (Ballester et al, 2013), almond trees (García-Tejero et al, 2012), bean (Durigon & van Lier, 2013), cotton (Padhi, Misraa, & Payerob, 2012), maize (Zandonadi et al, 2005), oak (Grant et al, 2010), strawberries (Grant et al, 2012 Daily mean canopy temperature, C T c,midday Daily midday canopy temperature, C DT Differences between T c,max and T c,min, C (T c ÀT a ) min Daily minimum differences between canopy and air temperatures, C (T c ÀT a ) max Daily maximum differences between canopy and air temperatures, C (T c ÀT a ) m Daily mean differences between canopy and air temperatures, C (T c ÀT a ) midday Daily midday differences between canopy and air temperatures, C D(T c ÀT a ) Differences between (T c ÀT a ) max and (T c ÀT a ) min, C VPD Vapour pressure deficit, kPa J stem Stem water potential, MPa J 100s…”

Heat stress is overestimated in climate impact studies for irrigated agriculture

“…Previous large scale assessments of the impact of heat stress on crop yields have been based on ambient air temperature T air (°C) measured at 2 m height at standard weather stations or projected by climate models (Asseng et al 2015, Deryng et al 2014, Lobell et al 2015, Semenov and Shewry 2011 despite evidence suggesting that the temperature at the top of the crop canopy T can (°C) is more relevant (Gourdji et al 2013a, Pinto et al 2010. T can can deviate by more than 10°C from T air (Blad et al 1988, Durigon andvan Lier 2013), even under temperate climate conditions . The difference between T can and T air is largely determined by the vapor pressure deficit and other local weather conditions, canopy and crop properties and the soil water content (Webber et al 2016b).…”

Soil Water Storage in Soybean Crop Measured by Polymer Tensiometers and Estimated by Agrometeorological Methods

“…The main and important difference is the possibility of linking them to dataloggers and have continuous readings. Their operational range extends from the saturation water content (θ s m 3 m -3 ) down to pressure heads around -15 atm, close to the permanent wilting point (PWP = -150 m), far beyond the range covered by conventional water-filled tensiometers (Durigon & de Jong van Lier, 2013). Due to their recent development, the polymer tensiometers are still very costly and not easily available in the market.…”

“…Measured values of h can be transformed to θ when the h(θ) relation (water retention curve) is known. Polymer tensiometer data have been used by Durigon et al (2011) and Durigon and de Jong van Lier (2013) polymer for laboratory observations; Durigon et al (2012) reported data from field measured values with this tensiometer.…”