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Radiation and Crops

Published online by Cambridge University Press:  03 October 2008

J. L. Monteith
Affiliation:
Rothamsted Experimental Station, Harpenden, Herts.*

Summary

The analysis of radiation climate is a central problem of agricultural meteorology because rates of photosynthesis depend on the receipt of visible light and rates of transpiration depend on the net exchange of radiation by a crop canopy. Both short-wave (solar) and long-wave (terrestrial) radiation are correlated with cloud amount, and in south-east England the income of net radiation in summer is proportional to the income of solar radiation.

In principle, the fraction of total radiation in the visible waveband depends on cloud cover and on the amount of absorption and scattering in the atmosphere, but in practice the fraction is often between 0·40 and 0·45. The calculation of photosynthetic efficiency needs a figure for the number of quanta (or Einsteins) per unit energy, and this figure can be calculated from the mean wavelength of the radiation weighted by energy, about 0·55μ for direct sunlight.

The reflection of radiation by vegetation changes with solar elevation, and at angles between 40° and 60° it ranges between 0·15 for a rough crop (e.g. pineapple) to 0·26 for smoother crops (e.g. sugar beet, kale). The transmission of radiation through the canopy can be expressed as a function of the leaf area index and a parameter that depends on the distribution and orientation of leaves.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1965

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References

REFERENCES

Anderson, M. C. (1964) Biol. Rev. 39, 425.CrossRefGoogle Scholar
Avaste, O., Moldau, H. & Shifrin, K. C. (1962). Rep. Inst. Phys. and Astron. of the Acad. of Estonian S.S.R 3, 23.Google Scholar
Berger-Landfelt, U. (1964). Ber. dt. bot. Ges. 77, 27.Google Scholar
Black, J. N. (1956) Archiv. Met. Geophys. Bioklim. B. 7, 12.Google Scholar
Black, J. N. (1960). Trans. Roy. Soc. South Aust. 83, 83.Google Scholar
Brunt, D. (1939) Physical and dynamical meteorology, Cambridge. Cambridge University Press.Google Scholar
Davies, J. (1965) Q. Jl. R. met. Soc. 91, 359.CrossRefGoogle Scholar
Drummond, A. J. (1958) Arch. Met. Geophys. Bioklim. B 9, 149.CrossRefGoogle Scholar
Ekern, P. C. (1965). J. Geoph. Res. 70, 785.CrossRefGoogle Scholar
Fleischer, R. (1956). Ber. dt. Wetterd. 22, 32.Google Scholar
Gates, D. M. (1965). Ecology 46, 1.CrossRefGoogle Scholar
Gates, D. M., Keegan, H. J., Schleter, J. C. & Weidner, V. R. (1965). Appl. Optics (in press).Google Scholar
Glover, J. & McCulloch, J. S. G. (1958) Q. Jl. R. met. Soc. 84, 172.CrossRefGoogle Scholar
Johnson, D. S. (1954) J. Met. 11, 431.2.0.CO;2>CrossRefGoogle Scholar
Lemon, E. (1963) In Environmental control of plant growth (ed. Evans, ). New York and London, Academic Press, 55.CrossRefGoogle Scholar
Monteith, J. L. (1959a). J. scient. Instrum. 36, 341.CrossRefGoogle Scholar
Monteith, J. L. (1959b). Q. Jl R. met. Soc. 85, 386.CrossRefGoogle Scholar
Monteith, J. L. (1961). Q. Jl R. met. Soc. 87, 171.CrossRefGoogle Scholar
Monteith, J. L. (1962) Q. Jl R. met. Soc. 88, 508.CrossRefGoogle Scholar
Monteith, J. L. (1965). Ann. Bot. 29, 17.CrossRefGoogle Scholar
Monteith, J. L. & Szeicz, G. (1961). Q. Jl R. met. Soc. 87, 159.CrossRefGoogle Scholar
Monteith, J. L. & Szeicz, G. (1962a). Q. Jl R. met. Soc. 88, 496.CrossRefGoogle Scholar
Monteith, J. L. & Szeicz, G. (1962b). Archiv. Met. Geophys. Bioklim. B. 11. 491.CrossRefGoogle Scholar
Moon, P. B. (1940). J. Franklin Inst. 230, 583.CrossRefGoogle Scholar
Page, J. K. (1961). U.N. Conference on New Sources of Energy. Document E/CONF. 35/S/98.Google Scholar
Robinson, G. D. (1964). Annals of the International Geophysical Year 32, 17.Google Scholar
Sauberer, F. & Härtel, O. (1959). Pflanze und Strahlung. Leipzig, Akademische Verlagsgesellschaft.Google Scholar
Schulze, R. (1962). Strahlentherapie, 119, 21.Google Scholar
Stanhill, G. (1961). Mimeographed reports of Small Watersheds Committee. Land Management Research Group Rehovot.Google Scholar
Stanhill, G. (1962). Bull. Res. Council Israel 116, 34.Google Scholar
Swinbank, W. C. (1963) Q. Jl R. met. Soc. 89, 339.CrossRefGoogle Scholar
Szeicz, G., Monteith, J. L. & dos Santos, J. M. (1964). J. appl. Ecol. 1, 169.CrossRefGoogle Scholar
Szeicz, G. (1965). Symp. British Ecol. Soc. (in press).Google Scholar
Watson, D. J. (1947). Ann. Bot. 11, 41.CrossRefGoogle Scholar