|Anderson, Raymond - Ray|
|LUND, C - California State University|
|MELTON, F - California State University|
|JOHNSON, L - California State University|
|Kustas, William - Bill|
Submitted to: Geological Society of America Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/14/2013
Publication Date: 5/20/2013
Citation: Anderson, R.G., Wang, D., Lund, C., Melton, F., Johnson, L., Prueger, J.H., Alfieri, J.G., Mckee, L.G., Kustas, W.P. 2013. Assessing evapotranspiration, basal crop coefficient, and irrigation efficiency in production peach orchard in California's San Joaquin Valley. Geological Society of America Meeting. Paper No. 30-5.
Technical Abstract: Accurate field scale observations of crop water use are necessary to maximize crop productivity with limited water resources and to parameterize regional and continental satellite models to estimate near real-time crop water use. However, rapid, continuous observations of field-scale water use in California’s diverse cropping systems have been historically limited. Here an integrated framework is presented to assess crop water use in a mature peach orchard in California’s San Joaquin Valley that combines micrometeorological, radiometric, and soil observations. Evapotranspiration (ET) measured with an Eddy Covariance tower was compared to soil water balance observations (SM), precipitation (P), and irrigation (I) measurements. Data from the first year of observation indicates a relatively high irrigation efficiency (ET>85% of P+I+dSM). Crop coefficient (Kc) had a peak value (~1.2-1.3 of reference ET) that was similar, but more variable than reported for lysimeter-grown peaches in California and which reached an elevated level (Kc>1) earlier in the season. Transpiration (T) was >80% of ET during midday in the growing season. The preliminary results highlight the need for better quantification of water extraction by mature peach trees from deeper soil layers. Additional observations in the upcoming year from the recently launched Landsat Data Continuity Mission should further enable additional quantification between orchard water use and remotely sensed observations.