Assessment of the Impact of Degree of soil compactness Indicator on Soil Hard-Setting Index and Soil Water Retention Curve in Gypsum-Containing Soils

Author's Information:

Ruwaida .Kh.Sabber

Soil Science & Water Resources Department, College of Agriculture, Tikrit University, Iraq

Vol 04 No 03 (2025):Volume 04 Issue 03 March 2025

Page No.: 230-238

Abstract:

Laboratory experiments were conducted to analyze the reflection of the soil compactness degree index (DC%) which represents the ratio between the apparent soil density (BD natural) and the critical apparent soil density (Proctor density) (BD ref.) in the soil stiffness index (H-index) and the Soil Moisture Retention Curve (SMRC) for seven soil samples with different gypsum content (60.12-414 g kg⁻¹). Soil specimens with gypsum contents of (G2) 111, (G3) 155, (G4) 219, (G5) 263, and (G6) 362 g kg⁻¹ They were prepared through mixing a low-gypsum surface soil sample (G1) containing 60.12 g kg⁻¹ gypsum with a high-gypsum subsurface soil sample (G7) containing 414 g kg⁻¹ gypsum. The soil moisture retention curve was determined for each gypsum soil sample at suction pressures of 0, 2, 7, 33, 100, 200, 500, 1000, and 1500 kPa after compacting the gypsum soil samples to densities of 1.4, 1.5, 1.6, and 1.8 Mg m⁻³. The Soil Hard-Setting Index (H-index) was calculated using the van Genuchten-Mualem equation and applying the RETC program. The results showed that the values of the soil stiffness index (H-index) increased with the increase of the compaction degree index (DC%), while the soil moisture retention curve decreased with the increase of the compacted soil bulk density, i.e., with the increase of the compaction degree index. Additionally, both the soil stiffness index and the compaction degree index decreased With the rising gypsum content in the soil.

KeyWords:

Degree of soil compactness Indicator ,Hard-Setting , Soil Moisture Retention Curve, Gypsiferous soils

References:

1. Aimrun, W., Amin, M. S. M., & Eltaib, S. M. (2004). Effective porosity of paddy soils as an estimation of its saturated hydraulic conductivity. Geoderma, 121(3-4), 197-203.‏

2. Al-Kayssi, A. W., & Mustafa, S. H. (2016). Modeling gypsifereous soil infiltration rate under different sprinkler application rates and successive irrigation events. Agricultural Water Management, 163, 66-74.‏

3. AL-Kayssi, A. W. (2021). Use of water retention data and soil physical quality index S to quantify hard-setting and degree of soil compactness indices of gypsiferous soils. Soil and Tillage Research, 206, 104805.‏

4. Al-Kayssi, A. W. (2016). Impact of successive wetting and drying cycles on some physical properties of gypsifereous soils. Journal of Agriculture Food and Development, 2, 5-15.‏

5. ASTM Standard D698, (2007). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort. ASTM, International, West Conshohocken, PA

6. Blacke, G.R., and K.H. Hortge. (1986). In methods of soil Analysis, part1. Physical and Mineralogical Methods_ Agronomy Monograph no. 9 (2nd Edition), American Society of Agronomy_ Soil Science Society of America, 677, south segoe Road, Madison, WI 53711, USA.

7. Dexter, A. R., Czyż, E. A., Richard, G., & Reszkowska, A. (2008). A user-friendly water retention function that takes account of the textural and structural pore spaces in soil. Geoderma, 143(3-4), 243-253.‏

8. Dexter, A. R., Czyż, E. A., Richard, G., and Reszkowska, A.( 2008). A user-friendly water retention function that takes account of the textural and structural pore spaces in soil. Geoderma, 143(3-4), 243-253.‏

9. Dexter, A.R., (2004a). Soil physical quality. Part I. Theory, effects of soil texture, density, and organic matter, and effects on root growth. Geoderma 120: 201–214.

10. Dexter, A.R., (2004b). Soil physical quality. Part II. Friability, tillage, tilth and hard-setting Geoderma 120: 215–225.

11. Farahani, E., Mosaddeghi, M. R., Mahboubi, A. A., and Dexter, A. R. (2019). Prediction of soil hard-setting and physical quality using water retention data. Geoderma, 338, 343-354.‏

12. Håkansson, I. (1990). A method for characterizing the state of compactness of the plough layer. Soil and tillage research, 16(1-2), 105-120.‏

13. Hillel, D. 1980. Fundamentals of Soil Physics. Academic Press, New York.

14. Klute, A. (1986). Water retension: Laboratory method of soil analysis Part 1, Physical and Mineralogical Method, 2nd ed. Edited. P.635-660.

15. Lagerwerff, J. V., G.W. Akin, S.W. Moses. 1965. Detection and determination of gypsum in soils. Soil Sci. Soc. Am. Proc. 29(5): 535-540.

16. Mosaddeghi, M. R., Morshedizad, M., Mahboubi, A. A., Dexter, A. R., and Schulin, R. 2009. Laboratory evaluation of a model for soil crumbling for prediction of the optimum soil water content for tillage. Soil and Tillage Research, 105(2), 242-250.‏

17. Mualem, Y. (1976). A new model for predicting the hydraulic conductivity of unsaturated porous media. Water resources research, 12(3), 513-522.‏

18. Pearson, M. J., Monteith, S. E., Ferguson, R. R., Hallmark, C. T., Hudnall, W. H., Monger, H. C., ... & West, L. T.( 2015). A method to determine particle size distribution in soils with gypsum. Geoderma, 237, 318-324.‏

19. Reichert, J. M., Suzuki, L. E. A. S., Reinert, D. J., Horn, R., & Håkansson, I. (2009). Reference bulk density and critical degree-of-compactness for no-till crop production in subtropical highly weathered soils. Soil and Tillage Research, 102(2), 242-254.‏

20. RETC (RETention Curve), (2008). RETC model. USDA-ARS U.S. SalinityLaboratory,Riverside,CA,USA.

21. Richards, L.A. (1954). Diagnosis and Improvement of Saline and Alkali Soil. U. S. D. A. Handbook No-60. USA.

22. Silva, S. R. D., Barros, N. F. D., Costa, L. M. D., and Leite, F. P. (2008). Soil compaction and eucalyptus growth in response to forwarder traffic.

23. Taylor, H. M. (1971). Effects of soil strength on seedling emergence, root growth and crop yield. Compaction of agricultural soils, 292, 312.‏

24. Van Genuchten, M. V., Leij, F. J., & Yates, S. R. (1991). The RETC code for quantifying the hydraulic functions of unsaturated soils.‏

25. Van Genuchten, M.TH. (1980). A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci. Soc. Am. J. 44(5): 892-898.

26. Vepraskas, M. J. (1984). Cone index of loamy sands as influenced by pore size distribution and effective stress. Soil Science Society of America Journal, 48(6), 1220-1225.‏

27. Wolkowski, R., and Lowery, B. (2008). Soil compaction: Causes, concerns, and cures (A3367).