Soil strength is an important quality of agricultural soils prone to traffic. Surface hardness (SH) measured by the Clegg Impact Tester (CIT) was evaluated as an indicator for assessing soil strength. Proctor tests were performed on a diverse range of soils to examine the relationships between bulk density (BD), penetration resistance (PR), SH and water content. All three indices showed typical response curves with increasing water content, with notable differences among the soils. Maximum dry bulk density (MDBD), peak penetration resistance (PPR) and peak surface hardness (PSH) showed values of 1.98 Mg m -3 , 8.2 MPa and 248 Cmax for Piarco, River Estate and Piarco respectively. Corresponding critical moisture contents (CMC) were much greater for MDBD compared to PPR and PSH. SH showed a significant positive correlation with PR, but not BD. Further divulgence into the relationships between SH and other soil properties as well as crop response will facilitate greater use of the CIT.
N. Ahmad, “Soils of the Caribbean,” Ian Randle Publishers, Kingston, 2011.
E. I. Ekwue, R. Stone and S. Ramphalie, “Engineering Properties of Some Wetland Soils in Trinidad,” Transactions of the ASABE, Vol. 18, No. 1, 2002, pp. 37-45.
M. N. Wuddivira, R. J. Stone and E. I. Ekwue, “Clay, Organic Matter and Wetting Effects on Splash Detachment and Aggregate Breakdown under Intense Rainfall,” Soil Science Society of America Journal Vol. 73, No. 1, 2009, pp. 226-232. doi:10.2136/sssaj2008.0053
W. J. Busscher, P. J. Bauer, C. R. Camp and R. E. Sojka, “Correction of Cone Index for Soil Water Content Differences in a Coastal Plain Soil,” Soil Tillage Research, Vol. 43, No. 3-4, 1997, pp. 205-217. doi:10.1016/S0167-1987(97)00015-9
J. Lipiec and R. Hatano, “Quantification of Compaction Effects on Soil Physical Properties and Crop Growth,” Geoderma, Vol. 116, No. 1-2, 2003, pp. 107-136. doi:10.1016/S0016-7061(03)00097-1
A. G. Bengough and C. E. Mullins, “Mechanical Impedance to Root Growth: A Review of Experimental Techniques and Root Growth Responses,” Journal of Soil Science, Vol. 41, No. 3, 1990, pp. 341-358. doi:10.1111/j.1365-2389.1990.tb00070.x
W. R. Whalley, J. Lipiec, W. Stepniewski and F. Tardieu, “Control and Measurement of the Physical Environment in Root Growth Experiments,” In: A. L. Smit, A. G. Bengough, C. Engels, M. van Noordwijk, S. Pellerin and S. C. van de Geijn, Eds., Root Methods A Handbook, Springer-Verlag, Berlin, 2000, pp. 76-112.
J. Glinski and J. Lipiec, “Soil Physical Conditions and Plant Roots,” CRC Press, Boca Raton, 1990.
D. J. Campbell and J. K. Henshall, “Bulk Density,” In: K. A. Smith and C. E. Mullins, Eds., Soil Analysis, Physical Methods, Marcel Dekker, New York, 1991, pp. 329-366.
J. T. Brosnan, A. S. McNitt and T. J. Serensits, “Effects of Varying Surface Characteristics on the Hardness and Traction of Baseball Field Playing Surfaces,” International Turf Society Research Journal, Vol. 11, 2009, pp. 1-13.
O. S. B. Al-Amoudi, I. M. Asi, H. I. A. Wahhab and Z. A. Khan, “Clegg Hammer-California Bearing Ratio Correlations,” Journal of Materials in Civil Engineering, Vol. 14, 2002, No. 6, pp. 512-523. doi:10.1061/(ASCE)0899-1561(2002)14:6(512)
J. N. Rogers III and D. V. Waddington, “Impact Absorption Characteristics on Turf and Soil Surfaces,” Agronomy Journal, Vol. 84, No. 2, 1992, 203-209. doi:10.2134/agronj1992.00021962008400020016x
G. W. Gee and D. Or, “Particle Size Analysis” In: J. H. Dane and G. C. Topp, Eds., Methods of Soil Analysis, Part (4), Physical Methods, 3rd Edition, SSSA, Madison, 2002, pp. 255-294
G. W. Thomas, “Soil pH and Soil Acidity,” In: D. L. Sparks, et al., Eds., Methods of Soil Analysis, Part (3), Chemical Methods, SSSA, Madison, 1996, pp. 475-490.
D. W. Nelson and L. E. Sommers, “Total Carbon, Organic Carbon and Organic Matter,” In: D. L. Sparks, et al., Eds., Methods of Soil Analysis, Part (3), Chemical Methods, SSSA, Madison, 1996, pp. 995-996.
R. B. Grossman and T. G. Reinsch, “Bulk Density and Linear Extensibility,” In: J. H. Dane and G. C. Topp, Eds., Methods of Soil Analysis, Part (4), Physical Methods, 3rd Edition, SSSA, Madison, 2002, pp. 201-228.
A. L. Flint and L. E. Flint, “Particle Density,” In: J. H. Dane and G. C. Topp, Eds., Methods of Soil Analysis, Part (4), Physical Methods, 3rd Edition, SSSA, Madison, 2002, pp. 229-241.
R. A. Mc Bride, “Atterberg Limits,” In: J. H. Dane and G. C. Topp, Eds., Methods of Soil Analysis, Part (4), Physical Methods, 3rd Edition, SSSA, Madison, 2002, pp. 389- 399.
R. J. Stone, E. I. Ekwue and R. O. Clarke, “Engineering Properties of Sewage Sludge in Trinidad,” Journal of Agricultural Engineering Research, Vol. 70, No. 2, 1998, pp. 221-230. doi:10.1006/jaer.1998.0266
F. B. Lopez and L. E. Chinnery, “Surface Hardness Characteristics of Cricket Pitches as Determined with the Clegg Hammer,” International Turf Society Research Journal, Vol. 11, 2009, pp. 38-40.
N. C. Brady and R. R. Weil, “The Nature and Properties of Soils,” 14th Editon, Prentice Hall, London, 2008
B. D. Kay and D. A. Angers, “Soil Structure,” In: M. E. Sumner, Ed., Handbook of Soil Science, CRC Press, New York, 1999, pp. A-229-A-269.
N. Ahmad and C. E. Davis, “The Effects of Drying on Release of Native and Added Potassium on Six West Indian Soils with Contrasting Mineralogy,” Soil Science, Vol. 112, No. 2, 1971, pp. 100-106. doi:10.1097/00010694-197108000-00003
A. R. Jumikis, “Soil Mechanics,” Robrt E Kriger Co., Malabar, 1984.
R. E. Sojka, W. J. Busscher and G. A. Lehrsch, “In Situ Strength, Bulk Density and Water Content Relationships of a Durinodic Xeris Haplocalcid Soil,” Soil Science, Vol. 166, No. 8, 2001, 520-529. doi:10.1097/00010694-200108000-00003
E. I. Ekwue and R. J. Stone, “Effect of Peat on the Compactibility of Some Trinidadian Soils,” Journal of Agricultural Engineering Research, Vol. 57, No. 2, 1994, pp. 129-136. doi:10.1006/jaer.1994.1012
R. J. Stone and E. I. Ekwue, “Soil Compressibility as Influenced by Sewage Sludge Incorporation,” Journal of Agricultural Engineering Research, Vol. 64, No. 3, 1996, pp. 227-235. doi:10.1006/jaer.1996.0063
M. Diaz-Zorita, J. H. Grove and E. Perfect, “Laboratory Compaction of Soils Using a Small Mold Procedure,” Soil Science Society of America Journal, Vol. 65, No. 6, 2001, pp. 1593-1598. doi:10.2136/sssaj2001.1593
D. L. McQueen and T. G. Shepherd, “Physical Changes and Compaction Sensitivity of a Fine-Textured, Poorly Drained Soil (Typic Endoaquept) under Varying Durations of Cropping Manawatu Regions, New Zealand,” Soil Tillage Research, Vol. 63, No. 3-4, 2002, pp. 93-107. doi:10.1016/S0167-1987(01)00231-8
E. I. Ekwue, “Organic Matter Effects on Soil Strength Properties,” Soil Tillage Research, Vol. 16, No. 3, 1990, pp. 289-297. doi:10.1016/0167-1987(90)90102-J
J. J. H. Van den Akker and B. Soane, “Compaction,” In: L. Rattan, Ed., Encyclopaedia of Soil Science, 2nd Edition, CRC Press, Boca Raton, 2005, pp. 285-293. doi:10.1021/ja0410542
C. Waltz, S. Burnett, V. Quisenberry and B. McCarty, “Soil Amendments Affect Compaction, Soil Strength,” Golf Course Management, Vol. 68, No. 11, 2000, pp. 49- 55.