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Irrigation Science

, Volume 6, Issue 1, pp 51–61 | Cite as

Evapotranspiration of citrus as affected by soil water deficit and soil salinity

  • H. M. du Plessis
Article

Summary

The extent to which evapotranspiration (ET) of Valencia citrus trees is affected by differing soil water depletions (SWD) and soil salinity regimes was determined during five seasons during which soil salinity levels varied. Three weighing lysimeters, each with a 14 year old tree, were used to measure daily ET and to schedule irrigation to maintain SWD at maxima of 15, 75 and 150 mm respectively. Tensiometers and salinity sensors were used to indicate the in situ soil matric and soil solution osmotic potentials. Total soil water potential was calculated from tensiometer and salinity sensor readings weighted for root density with depth. The total of these for the summer months was found to be linearly related (Fig. 5) to the mean ET/Ep (Ep=A-pan evaporation). The slope and threshold of ET reductions with decreasing soil water potential for the low frequency irrigation treatment (150 mm SWD) show good agreement with the slope and threshold of yield decrease that is calculated from soil salinity in the lysimeter using previously reported salinity-yield relationships. The reduced water uptake due to increasing soil salinity has important implications for soil salinity control, since the lower uptake should in theory increase the leaching fraction. This implies a degree of self adjustment to the leaching fraction when irrigating with increasingly saline waters if water applications are scheduled as for non-saline conditions.

Keywords

Soil Salinity Irrigation Treatment Soil Water Potential Citrus Tree Soil Water Deficit 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Bernstein L, Francois LE (1973) Leaching requirement studies: Sensitivity of alfalfa to salinity of irrigation and drainage waters. Proc Soil Sci Soc Am 37:931Google Scholar
  2. Bielorai H (1977) The effect of drip and sprinkler irrigation on grapefruit yield, water use and soil salinity. Proc Int Soc Citriculture, pp 99–103Google Scholar
  3. Bielorai H (1978) The prospects of water management for optimum citrus growth and production. Proc Int Soc Citriculture, pp 227–233Google Scholar
  4. Bielorai H, Shalhevet J, Levy Y (1978) Grapefruit response to variable salinity in irrigation. Irrig Sci 1:61Google Scholar
  5. Fuchs M, Green GC (1982) Of trees, water and men. S Afr J Sci 78:226Google Scholar
  6. Green GC, Bruwer W (1979) An improved weighing lysimeter facility for citrus evapotranspiration studies. Water SA 5:189Google Scholar
  7. Green GC, Du Plessis HM (1983) Irrigation requirements of citrus and salinity control in citrus orchards. Proc XXI Int Hort Congr 1:338Google Scholar
  8. Green GC, Moreshet S (1979) An analysis of seasonal water use characteristics of Valencia orange trees in the Sunday River Valley. Crop Prod 8:179Google Scholar
  9. Hanks RJ, Ashcroft GL, Rasmussen VP, Wilson GD (1978) Corn production as influenced by irrigation and salinity — Utah studies. Irrig Sci 1:47Google Scholar
  10. Kalma JD, Stanhill G (1969) Transpiration, evaporation and deep drainage losses from an orange plantation. Isr J Agric Res 19:11Google Scholar
  11. Maas EV, Hoffman GJ (1977) Crop salt tolerance — current assessment. J Irrig Drainage Div ASCE 103:115Google Scholar
  12. Monteith JL (1981) Evaporation and surface temperature. Q JR Meteorol Soc 107:1Google Scholar
  13. Moreshet M, Cohen Y, Fuchs M (1983) Response of mature ‘sha mouti’ orange trees to irrigation of different soil volumes at similar levels of available water. Irrig Sci 3:223Google Scholar
  14. Richards LA (1966) A salinity sensor of improved design. Proc Soil Sci Soc Am 30:333Google Scholar
  15. Shainberg I, Oster JD (1978) Quality of irrigation water. Intern. Irrig Inf Center Publ No 2. Volcani Center, Bet Dagan, IsraelGoogle Scholar
  16. US SalLab Staff (1954) Diagnosis and improvement of saline and alkali soils. Handbook 60. US Dept Agric, p 160Google Scholar
  17. Van Schilfgaarde J, Bernstein L, Rhoades JD, Rawlins SL (1974) Irrigation management for salt control. J Irrig Drainage Div ASCE 100:321Google Scholar

Copyright information

© Springer-Verlag 1985

Authors and Affiliations

  • H. M. du Plessis
    • 1
  1. 1.Soil and Irrigation Research InstitutePretoriaSouth Africa

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