Hostname: page-component-7479d7b7d-qlrfm Total loading time: 0 Render date: 2024-07-09T17:46:52.307Z Has data issue: false hasContentIssue false

Modelling the field drying of hay

Published online by Cambridge University Press:  27 March 2009

N. Thompson
Affiliation:
Meteorological Office, London Road, Brachnell, Berkshire, R612 2SZ

Summary

The loss of moisture from swaths drying in the field has been investigated using bulk and multi-layer micrometeorological models of an idealized swath. The models produced almost identical results for the variations with time of the swaths' mean moisture contents but the multi-layer version showed in addition the results to be expected from tedding, and the effects of transpiring stubble and evaporation from an underlying moist soil surface on swath drying. The models reproduced in broad detail changes of swath moisture, including rain and dew intercepted by the swath, which had been observed in experiments on grass wilting. However, there appeared to be under-estimation of the rate at which the swath tissue absorbed moisture when the swath contained surface water. The bulk model reduces to a very simple formula when used with typical swath resistances, revealing the importance of both sunshine and vapour pressure deficit in promoting drying, and demonstrating the adverse effect of wind; the model lends itself to the routine classification from daily climatological data of days suitable for hay drying.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1981

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Agena, M. U., Batjer, D. & Wessels, G. (1968). Wieviel ‘Einfuhrtage’ stehen im nordwestdeutsohen Raum fur die Bergung von Winterfutter zur Verfügung? Meteorologische Rundschau 21, 169175.Google Scholar
Brück, I. G. M. & Van Elderen, E. (1969). Field drying of hay and wheat. Journal of Agricultural Engineering Research 14, 105116.CrossRefGoogle Scholar
Clark, B. J. & McDonald, P. (1977). The drying pattern of grass swaths in the field. Journal of the British Grassland Society 32, 7781.CrossRefGoogle Scholar
Couturier, D. E. & Rifley, E. A. (1973). Rainfall interception in mixed grass prairie. Canadian Journal of Plant Science 53, 659663.CrossRefGoogle Scholar
Denmead, O. T. (1976). Temperate cereals. In Vegetation and the Atmosphere Vol. II (ed. Monteith, J. L.), pp. 131. London: Academic Press.Google Scholar
Dyer, A. J. (1967). The turbulent transfer of heat and water vapour in an unstable atmosphere. Quarterly Journal of the Royal Meteorological Society 93, 501508.CrossRefGoogle Scholar
Dyer, J. A. & Brown, D. M. (1977). A climatic simulator for field-drying hay. Agricultural Meteorology 18, 3748.CrossRefGoogle Scholar
Dyer, A. J. & Hicks, B. B. (1970). Flux-gradient relationships in the constant flux layer. Quarterly Journal of the Royal Meteorological Society 96, 715721.CrossRefGoogle Scholar
Firth, D. R. & Leshem, Y. (1976). Water loss from cut herbage in the windrow and from isolated leaves and stems. Agricultural Meteorology 17, 261269.CrossRefGoogle Scholar
Gadd, A. J. & Keers, J. F. (1970). Surface exchanges of sensible and latent heat in a 10-layer model atmosphere. Quarterly Journal of the Royal Meteorological Society 96, 297308.CrossRefGoogle Scholar
Gates, D. M. (1980). Biophysical Ecology. New York: Springer-Verlag.CrossRefGoogle Scholar
Grant, D. R. (1975). Comparison of evaporation from barley with Penman estimates. Agricultural Meteorology 15, 4960.CrossRefGoogle Scholar
Harris, C. E. & Tullbero, J. N. (1980). Pathways for water loss from legumes and grasses cut for conservation. Orass and Forage Science 35, 111.CrossRefGoogle Scholar
Hill, J. D. (1976). Predicting the natural drying of hay. Agricultural Meteorology 17, 195204.CrossRefGoogle Scholar
Hughes, T., McMullan, J. T., Morgan, R. & Murray, R. D. (1977). On the optimum orientation of solar collectors. Energy Research 1, 143156.CrossRefGoogle Scholar
Jones, L. (1976). Annual Report of the Grassland Research Institute 1974, pp. 4950.Google Scholar
Lumb, F. E. (1964). The influence of cloud on the hourly amounts of radiation at the sea surface. Quarterly Journal of the Royal Meteorological Society 90, 4356.CrossRefGoogle Scholar
Monteith, J. L. (1958). The heat balance of soil beneath crops. Arid Zone Research XI – Climatology and Microclimatology, Proceedings of the Canberra Symposium, October 1956, UNESCO, pp. 123128.Google Scholar
Monteith, J. L. (1965). Evaporation and environment, Symposium of the Society for Experimental Biology 19, 205234.Google ScholarPubMed
Monteith, J. L. (1973). Principles of Environmental Physics. London: Edward Arnold.Google Scholar
Monteith, J. L. & Szeicz, G. (1961). The radiation balance of bare soil and vegetation. Quarterly Journal of the Royal Meteorological Society 87, 159170.CrossRefGoogle Scholar
Monteith, J. L., Szeicz, G. & Waggoner, P. E. (1965). The measurement and control of stomatal resistance in the field. Journal of Applied Ecology 2, 345355.CrossRefGoogle Scholar
Paulson, C. A. (1970). The mathematical representation of wind speed and temperature profiles in the surface layer. Journal of Applied Meteorology 9, 857861.2.0.CO;2>CrossRefGoogle Scholar
Rao, K. S., Wyngaard, J. C. & Coté, O. R. (1974). Local advection of momentum, heat and moisture in micrometeorology. Boundary-Layer Meteorology 7, 331348.CrossRefGoogle Scholar
Ripley, E. A. & Redmann, R. E. (1976). Grassland. In Vegetation and the Atmosphere Vol. II (ed. Monteith, J. L.), pp. 349398. London: Academio Press.Google Scholar
Shepherd, W. (1958). Moisture relations of hay species. Australian Journal of Agricultural Research 9, 437445.CrossRefGoogle Scholar
Sparks, W. R. (1980). Agricultural Memorandum No. 875 (an unpublished paper, available from the National Meteorological Library, Bracknell).Google Scholar
Spatz, G., Van Eimern, J. & Lawrynowicz, R. (1970). Der Trocknungsverlauf von Heu im Freiland. Bayerisches Landwirtschaftliches Jahrbuch 1970 47, 446464.Google Scholar
Szeicz, G. & Long, I. F. (1969). Surface resistance of crop canopies. Water Resources Research 5, 622633.CrossRefGoogle Scholar
Thom, A. S. (1975). Momentum, mass and heat exchange of plant communities. In Vegetation and the Atmosphere Vol. I (ed. Monteith, J. L.), pp. 57109. London: Academic Press.Google Scholar
Thompson, N. (1981). The duration of leaf wetness. The Meteorological Magazine 110, 112.Google Scholar
Uchijima, Z. (1976). Maize and rioe. In Vegetation and the Atmosphere Vol. II (ed. Monteith, J. L.), pp. 3364. London: Academio Press.Google Scholar
Utaaker, K. (1966). A study of the energy exohanges at the earth's surface. Årbok for Universitet i Bergen, Mat.-Naturu. Serie, 1966 No. 1. Bergen/Oslo: Norwegian Universities Press.Google Scholar
van Elderen, E., de Feijter, J. & van Hoven, S. P. J. H. (1972). Moisture in a grass sward. Journal of Agricultural Engineering Research 7, 209218.CrossRefGoogle Scholar
Waggoner, P. E., Furnival, G. M. & Reifsnyder, W. E. (1969). Simulation of the microclimate of a forest. Forest Science 15, 3745.Google Scholar
Waggoner, P. E. & Reifsnyder, W. E. (1968). Simulation of the temperature, humidity and evaporation profiles in a leaf canopy. Journal of Applied Meteorology 7, 400409.2.0.CO;2>CrossRefGoogle Scholar
Webb, E. K. (1970). Profile relationships: the log-linear law and extension to strong stability. Quarterly Journal of the Royal Meteorological Society 96, 6790.CrossRefGoogle Scholar