Summary
Experimental methods are described for observing the behaviour of roots encountering cracks in soil. The proportions of roots which enter a second soil block after crossing a crack of known width were measured. Soil strength was measured with a penetrometer.
Results are presented for the proportions of seminal roots of wheat and primary lateral roots of pea which enter moulded soil of various strengths after crossing cracks. Results are also presented for the proportions of seminal roots of pea, rape and safflower which enter undisturbed soil after crossing cracks.
It was found that, in all cases, the proportion of roots penetrating the second soil block decreased with increasing crack width and increasing soil strength. Also, a smaller proportion of thinner roots penetrated the second soil block than thicker roots under similar conditions. Root diameter in the cracks was influenced by both crack width and soil strength, and an empirical equation is presented to describe this effect.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Dexter A R 1978 A stochastic model for the growth of roots in tilled soil. J. Soil Sci. 29, 102–116.
Dexter A R and Hewitt J S 1978 The deflection of plant roots. J. Agric. Eng. Res. 23, 17–22.
Hewitt J S and Dexter A R 1979 An improved model of root growth in structured soil. Plant and Soil 52, 325–343.
Hewitt J S and Dexter A R 1984 The behaviour of roots encountering cracks in soil. II. Development of a predictive model. Plant and SoilIn press.
Northcote K H 1971 A factual, key for the Recognition of Australian Soils (3rd Edition). Rellim Tech. Publs., Adelaide, South Australia, 122 p.
Oades J M, Lewis D G and Norrish K 1981 Red-brown Earths of Australia. Univ. of Adelaide and CSIRO Division of Soils, South Australia, 168 p.
Smith G 1960 Soil Classification, a Comprehensive System, Seventh Approximation. U.S. Dept. Agric., 265 p.
Stace H C T, Hubble G D, Brewer R, Northcote K H, Sleeman J R, Mulcahy M J and Hallsworth E G 1968 A Handbook of Australian Soils. Rellim Tech., Publs., Adelaide, South Australia, 429 p.
Whiteley G M and Dexter A R 1981 The dependence of soil penetrometer pressure on penetrometer size. J. Agric. Eng. Res. 26, 467–476.
Whiteley G M and Dexter A R 1982 The buckling of plant roots. Physiol. Plant. 54, 333–342.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Whiteley, G.M., Dexter, A.R. The behaviour of roots encountering cracks in soil. Plant Soil 77, 141–149 (1984). https://doi.org/10.1007/BF02182918
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02182918