Hilgardia
Hilgardia
Hilgardia
University of California
Hilgardia

The use of calculated actual and potential evapotranspiration for estimating potential plant growth

Authors

Rodney J. Arkley
Rudolph Ulrich

Authors Affiliations

Rodney J. Arkley was Lecturer in Soils and Plant Nutrition and Specialist in the Experiment Station, Berkeley; Rudolph Ulrich was Soil Scientist, Soil Conservation Service, Berkeley.

Publication Information

Hilgardia 32(10):443-469. DOI:10.3733/hilg.v32n10p443. May 1962.

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Abstract

Potential evaporation, ETp, can readily be calculated from monthly mean temperatures by means of tables and nomograms now available in the literature. Actual evapotranspiration, ETa, is calculated from ETp by taking precipitation and the water-holding capacity of the soil into account. Either value can be calculated for the whole year (ETp or ETa) if frost-tolerant plants are under consideration; or for the frost-free period (ETp 32° or ETa 32°) if frost-sensitive plants are under consideration.

All four values—ETp, ETa, ETp 32°, and ETa 32°—were calculated for 211 California stations and for 27 Nevada and Oregon stations near California. Plotting these values for 25 stations along a traverse through central California and western Nevada reveals great differences from coast to inland stations, and from low to high altitudes. Comparison of the values with natural vegetation and with crops in the different regions indicates that the values are useful as indexes of expected growth of cultivated crops, range, and forest. ETp values are useful if moisture is not limiting, as in humid climates or where irrigation water is available; ETa values are useful for predicting the suitability of a climate for dry-farmed crops, estimating the potential for increased growth obtainable by irrigation, and for more precise studies of the effects of climate on natural vegetation. The indexes, used together, can be helpful in crop selection and other soil-management decisions.

Isograms of the four ET values, based on all California stations and plotted on maps of the state, furnish much information about those climatic limitations on plant growth that involve moisture and temperature relations.

Literature Cited

Arkley R. J. The water balance approach to the study of soil-climate relationships. 1961. 186 University of California Ph.D. dissertation. (Typed.6)

Blaney H. F., Criddle W. D. Determining water requirements in irrigated areas from climatological and irrigation data. U. S. Soil Conservation Service, SCS-TP. 1950. 96:1-48.

Briggs L. J., Shantz H. L. Relative water requirements of plants. Jour. Agr. Res. 1914. 3:1-63. 7 plates

Hutchings T. B. Arizona heat and moisture indexes for use in land capability classification. U. S. Soil Conservation Service. 1954 a. M-521:1-41. (Mimeo.)

Hutchings T. B. Colorado heat and moisture indexes for use in land capability classification. U. S. Soil Conservation Service. 1954b. M-522:1-41. (Mimeo.)

Hutchings T. B. New Mexico heat and moisture indexes for use in land capability classification. U. S. Soil Conservation Service. 1954c. M-523:1-52. (Mimeo.)

Hutchings T. B. Utah heat and moisture indexes for use in land capability classification. U. S. Soil Conservation Service. 1954d. M-524:1-32. (Mimeo.)

Hutchings T. B. Heat and moisture indexes for use in the capability classification [Idaho]. 1955. Boise, Idaho: U. S. Soil Conservation Service. 25p. (Mimeo.)

Kiesselbach T. A. Transpiration as a factor in crop production. Nebraska Agr. Exp. Sta. Res. Bul. 1916. 6:1-214. Illus

Kimball M. H., Brooks F. A. Plantclimates of California. California Agr. 1959. 13(5):7-12.

Palmer W. C., Havens A. V. A graphical technique for determining evapotranspiration by the Thornthwaite method. U. S. Weather Bureau, Weath. Rev. 1958. 86(4):123-28. DOI: 10.1175/1520-0493(1958)086<0123:AGTFDEreplacecodegt2.0.CO;2 [CrossRef]

Pelton W. L., King K. M., Tanner C. B. An evaluation of the Thornthwaite and mean temperature methods of determining potential evapotranspiration. Agron. Jour. 1960. 52:387-95.

Penman H. L. Natural evaporation from open water, bare soil and grass. Roy. Soc. London, Proc. A. 1948. 193:120-46. DOI: 10.1098/rspa.1948.0037 [CrossRef]

Pruitt W. O. Irrigation timetable. What’s New in Crops and Soils. 1958. 10(Apr.-May):7

Smith G. W. The determination of soil moisture under a permanent grass cover. Jour. Geophys. Res. 1959. 64(4):477-83. DOI: 10.1029/JZ064i004p00477 [CrossRef]

Thornthwaite C. W. An approach towards a rational classification of climate. Geog. Rev. 1948. 38:55-94. DOI: 10.2307/210739 [CrossRef]

Thornthwaite C. W., Mather J. R. The water balance. Drexel Inst. Tech. Publ. in Climatol. 1954. 8(1):104 DOI: 10.1097/00010694-195904000-00024 [CrossRef]

Thornthwaite C. W., Mather J. R. The water budget and its use in irrigation 1955. pp.346-58. In: Water. U. S. Dept. Agr. Yearbook of Agr. 1955

U. S. Weather Bureau. Climate of the states: California. Climatology of the United States, No. 60-4. 1959. Washington, D.C.: U. S. Dept. of Commerce.

van Hylckama T. E. C. A nomogram to determine monthly potential evapotranspiration. U. S. Weather Rev. 1959. 87:3 107-10, March DOI: 10.1175/1520-0493(1959)087<0107:ANTDMPreplacecodegt2.0.CO;2 [CrossRef]

Arkley R, Ulrich R. 1962. The use of calculated actual and potential evapotranspiration for estimating potential plant growth. Hilgardia 32(10):443-469. DOI:10.3733/hilg.v32n10p443
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