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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Water Management and Systems Research » Research » Publications at this Location » Publication #367895
Research Project: Improving the Sustainability of Irrigated Farming Systems in Semi-Arid Regions

Location: Water Management and Systems Research

Title: Maize differences in soil moisture changes and canopy temperature under varying water × nitrogen treatments

Author
item LO, TSZ - University Of Nebraska
item RUDNICK, DAREN - University Of Nebraska
item DeJonge, Kendall
item BAI, GENG - University Of Nebraska
item NAKABUYE, HOPE - University Of Nebraska
item KATIMBO, ABIA - University Of Nebraska
item GE, YUFENG - University Of Nebraska
item FRANZ, TRENTON - University Of Nebraska
item QIAO, XIN - University Of Nebraska
item HEEREN, DEREK - University Of Nebraska

Submitted to: Irrigation Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/22/2020
Publication Date: 8/21/2020
Citation: Lo, T.H., Rudnick, D.R., DeJonge, K.C., Bai, G., Nakabuye, H.N., Katimbo, A., Ge, Y., Franz, T.E., Qiao, X., Heeren, D.M. 2020. Maize differences in soil moisture changes and canopy temperature under varying water × nitrogen treatments. Irrigation Science. 38:519-534. https://doi.org/10.1007/s00271-020-00683-2.
DOI: https://doi.org/10.1007/s00271-020-00683-2

Interpretive Summary: To investigate further the nitrogen (N) effects on soil moisture changes and on canopy temperature, three irrigation levels × four N fertilizer levels were imposed on two growing seasons of maize in west central Nebraska, USA. At all irrigation levels, soil water loss over month-long intervals were generally greater as N fertilizer levels increased. Jointly considering canopy reflectance and soil moisture shows potential to explain much of the variation in estimated instantaneous water use among plots.

Technical Abstract: Crop nitrogen (N) status is known to affect crop water status and crop water use. Nevertheless, this particular interaction between water and N is sometimes downplayed or oversimplified. To investigate further the N effects on soil moisture changes and on canopy temperature, three irrigation levels × four N fertilizer levels were imposed on two growing seasons of maize in west central Nebraska, USA. Soil moisture changes were measured using a neutron probe, whereas canopy temperature was measured using infrared thermometers on a ground based mobile platform. At all irrigation levels, soil water loss over month-long intervals were generally greater as N fertilizer levels increased. Early afternoon canopy temperatures were usually lower with more fertilizer N given equal irrigation, but no trend or even the opposite trend was occasionally observed. Jointly considering canopy reflectance and soil moisture 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.