Spatial estimation of crop evapotranspiration, soil properties, and infiltrated water for scheduling cotton surface irrigations

Douglas J. Hunsaker, Andrew N. French, Eduardo M. Bautista, Kelly R. Thorp, Peter M. Waller, Patrick D. Royer, Pedro Andrade-Sanchez, J. Heun

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Estimates of spatially distributed crop evapotranspiration (ETc) over large fields could be particularly valuable for aiding irrigation management decisions in arid regions where surface irrigation systems are predominant. The objectives are to evaluate an irrigation scheduling approach that combines remote sensing inputs with field data to provide fine-scale, spatial monitoring of crop water use and soil water status within surface-irrigated fields. Remote sensing observations of vegetation index were used to spatially estimate basal crop coefficients within 4-m x 8-m zones within borders of a 4.9-ha cotton field. These data were used to compute ETc within zones using FAO-56 procedures. Spatial inputs of soil properties were estimated from a ground-based apparent soil electrical conductivity survey. Spatial distribution of infiltrated water along the furrow was estimated using hydraulic field measurements and irrigation simulation software. An existing daily time-step, soil water balance computer program was modified to incorporate the spatial information and provide simultaneous monitoring of crop and soil conditions in zones. Irrigation scheduling using the spatial monitoring approach compared favorably in yield to traditional cotton irrigation scheduling used in the area, but reduced water use by 7 to 9%, whereas it attained as much as 19% higher yield compared to scheduling based on assuming a uniform crop coefficient for all zones. Managing water for large surface-irrigated fields aided by decision support tools and approaches that allow spatial monitoring of crop water use and soil conditions could improve precision and timing of irrigation water scheduling.

Original languageEnglish (US)
Title of host publicationASABE - 5th National Decennial Irrigation Conference 2010, Held in Conjunction with Irrigation Show 2010
Pages748-760
Number of pages13
StatePublished - Dec 1 2010
Event5th National Decennial Irrigation Conference 2010, Held in Conjunction with Irrigation Show 2010 - Phoenix, AZ, United States
Duration: Dec 5 2010Dec 8 2010

Publication series

NameASABE - 5th National Decennial Irrigation Conference 2010, Held in Conjunction with Irrigation Show 2010
Volume2

Other

Other5th National Decennial Irrigation Conference 2010, Held in Conjunction with Irrigation Show 2010
CountryUnited States
CityPhoenix, AZ
Period12/5/1012/8/10

Keywords

  • Apparent soil electrical conductivity
  • Irrigation scheduling
  • Precision agriculture
  • Remote sensing
  • Vegetation index

ASJC Scopus subject areas

  • Agronomy and Crop Science

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  • Cite this

    Hunsaker, D. J., French, A. N., Bautista, E. M., Thorp, K. R., Waller, P. M., Royer, P. D., Andrade-Sanchez, P., & Heun, J. (2010). Spatial estimation of crop evapotranspiration, soil properties, and infiltrated water for scheduling cotton surface irrigations. In ASABE - 5th National Decennial Irrigation Conference 2010, Held in Conjunction with Irrigation Show 2010 (pp. 748-760). (ASABE - 5th National Decennial Irrigation Conference 2010, Held in Conjunction with Irrigation Show 2010; Vol. 2).