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ARS Home » Pacific West Area » Riverside, California » Agricultural Water Efficiency and Salinity Research Unit » Research » Publications at this Location » Publication #404356

Research Project: Water Management for Crop Production in Arid and Semi-Arid Regions and the Safe Use of Alternative Water Resources

Location: Agricultural Water Efficiency and Salinity Research Unit

Title: Assessment of crop water use and evaporation changes in a perennial orange orchard following a major thinning operation

item Anderson, Raymond - Ray
item Wang, Dong
item Dhungel, Ramesh
item AJAMI, HOORI - University Of California, Riverside
item Skaggs, Todd

Submitted to: Biological Engineering (ASABE)
Publication Type: Abstract Only
Publication Acceptance Date: 5/31/2023
Publication Date: 10/27/2023
Citation: Anderson, R.G., Wang, D., Dhungel, R., Ajami, H., Skaggs, T.H. 2023. Assessment of crop water use and evaporation changes in a perennial orange orchard following a major thinning operation. Biological Engineering (ASABE). N/A.

Interpretive Summary:

Technical Abstract: The Southeastern San Joaquin Valley (SJV), California, USA, is a major production region for high-value perennial specialty crops such as citrus. However, long-term changes in Californian climate and future regulatory action are expected to greatly constrain available irrigation supplies for perennial crops. Therefore, farmers have increased need to improve water use efficiency and water productivity. In the SJV’s Kaweah River Basin, citrus is a major agricultural crop with a large water footprint due to its year-round evapotranspiration (ET) from its evergreen canopy. Citrus orchards are also frequently and often heavily pruned to maintain tree vigor and improve harvest access. However, the impact of these practices on ET and water use efficiency is uncertain. In this study, we use a multi-year eddy covariance (EC) data set from a navel orange orchard that saw a major pruning operation in late 2021 that removed 50% of the trees. We evaluate changes in ET following the pruning via comparison with another citrus EC site that was not pruned. We also apply a flux variance partitioning approach (FLUXPART) to evaluate the relative changes in E and T. Results showed that pruning reduced overall ET at the site by ~150 mm in the first year post-pruning with greater daily variance in ET indicating that reduced T was significantly counteracted by higher soil E. The results illustrate the importance of canopy management in controlling ET and highlight the need for continued work as alternative citrus production systems (e.g. trellised citrus) become more prevalent.