Differences in soil water changes and canopy temperature under varying water × nitrogen sufficiency for maize

Abstract

Crop nitrogen (N) status is known to affect crop water status and crop water use. To investigate further the N effects on soil water changes and on canopy temperature, three water levels × four N levels were imposed on two growing seasons of maize in west central Nebraska, USA. Soil water changes were measured using a neutron probe, whereas canopy temperature was measured using infrared thermometers on a ground-based mobile platform. At all water levels, soil water losses over monthlong intervals were generally greater as N levels increased. Given equal water levels, early afternoon canopy temperatures were usually lower with higher N levels, but no trend or even the opposite trend was occasionally observed. Jointly considering canopy reflectance and soil water depletion shows potential to explain much of the variation in estimated instantaneous water use among plots. However, determining the relative contributions of the canopy and soil factors on a particular day may require season-to-date knowledge of the crop. Further research on assimilating such sensor data for a combined stress coefficient would improve crop modeling and irrigation scheduling when variable water sufficiency and variable N sufficiency are simultaneously significant.

Cumulative Deficit Irrigation and Nitrogen Effects on Soil Water Trends, Evapotranspiration, and Dry Matter and Grain Yield of Corn under High Frequency Sprinkler Irrigation

“…Results from other studies have been mixed as to the effect of fertility on ET c . Pandey et al (2000a), Ogola et al (2002), Lenka et al (2009), Rudnick et al (2017), andLo et al (2020) reported a significant decrease in corn ET c as nitrogen availability decreased. Conversely, Carlson et al (1959), Allen (1990), andFernández et al (1996) reported no effect of nutrient availability on ET c .…”

“…6). Conventional thinking assumes that reduced crop growth results in reduced ET c as there is less leaf area for transpiration (Lo et al, 2020). Results from other studies have been mixed as to the effect of fertility on ET c .…”

“…Most studies investigating corn grain yield response to water have been conducted using non-yield limiting fertility regimes. A few studies have investigated the interaction between crop water use and nutrient availability (Carlson et al, 1959;Eck, 1984;Allen, 1990;Fernández et al, 1996;Pandey et al, 2000aPandey et al, , 2000bHati et al, 2001;Ogola et al, 2002;Lenka et al, 2009;Rudnick and Irmak, 2013;Rudnick et al, 2017;Lo et al, 2020). Nitrogen (N) fertilizer had a significant effect on ET c in the studies of Pandey et al (2000aPandey et al ( , 2000b, Ogola et al (2002), Lenka et al (2009), Rudnick and Irmak (2013), Rudnick et al (2017), andLo et al (2020).…”

“…A few studies have investigated the interaction between crop water use and nutrient availability (Carlson et al, 1959;Eck, 1984;Allen, 1990;Fernández et al, 1996;Pandey et al, 2000aPandey et al, , 2000bHati et al, 2001;Ogola et al, 2002;Lenka et al, 2009;Rudnick and Irmak, 2013;Rudnick et al, 2017;Lo et al, 2020). Nitrogen (N) fertilizer had a significant effect on ET c in the studies of Pandey et al (2000aPandey et al ( , 2000b, Ogola et al (2002), Lenka et al (2009), Rudnick and Irmak (2013), Rudnick et al (2017), andLo et al (2020). Conversely, N fertility had no significant effect on ET c in the studies of Carlson et al (1959) and Fernández et al (1996), and Allen (1990) reported no significant effect of phosphate fertility on ET c for barley but did find a reduction in soil water evaporation with phosphate application.…”

Special issue: improving irrigation management across the Ogallala aquifer, USA

“…Costa-Filho et al (2020) developed a procedure to calculate a crop water stress index (CWSI) based on sensible heat flux estimated using a within canopy or aerodynamic temperature approach, and related CWSI to a soil water stress (deficit) index (SWSI). Lo et al (2020) monitored changes in soil water and maize canopy temperatures under varying levels of water and nitrogen applications, and introduced the concept of a combined stress coefficient that considers both variables. Schneekloth et al (2020) evaluated the effects of tillage and residue management on maize grain yield, water infiltration, evapotranspiration, and soil physical attributes under limited irrigation in a semi-arid climate.…”