Relationship between soil water retention model parameters and structure stability

Abstract

Studying and modeling the effects of soil properties and management on soil structure and near saturation water retention is vital for the development of effective soil and water conservation practices. The contribution of soil intrinsic properties and extrinsic conditions to structure stability was inferred, in quantitative terms, from changes in water retention curves near saturation (low matric potential, 0-50 cm, macropores > 60 µm) that were obtained by the high energy moisture characteristic (HEMC) method. The S-shaped water retention curves were characterized by the modified van Genuchten model that provided: (i) the model parameters α and n, which represent the location of the inflection point and the steepness of the water retention curve, respectively; and (ii) the soil structure index, SI=VDP/MS, where VDP is the volume of drainable pores, and MS is the modal suction. Model parameters, claculated by the soil-HEMC model, were related to soil properties and hence soil water retention properties were linked to measured characteristics in several field and laboratory experiments. Soil SI increased exponentially with the increase in α and the decrease in n, while the relationship between SI and α/n was linear. An improved description of the water retention and its link to pore and apparent aggregate size distribution, by using the model parameters α and n, could potentially assist in the selection of management practices for obtaining the most suitable type of soil structure depending on the desired soil function. 

Keywords

• Structure stability, water retention, pore size, stability index, model

References

1. Bolan, N.S., Szogi, A.A., Chuasavathi, T., Seshadri, B., Rothrock M.J., Panneerselvam, P., 2010. Uses and management of poultry litter. World's Poultry Science Journal 66(4): 673-698.
2. Bronick, C.J., Lal, R., 2005. Soil structure and management: a review. Geoderma 124(1-2): 3-22.
3. Gumus, I., Seker, C., 2014. Residual effect of different organic manure application on wheat yield in corn-wheat rotation. Soil-Water Journal 3(1): 1-5.
4. Haynes, R.J., 2000. Interactions between soil organic matter status, cropping history, method of quantification and sample pretreatment and their effects on measured aggregate stability. Biology and Fertility of Soils 30(4): 270–275.
5. Hinsinger, P., Gobran, G.R., Gregory, P.J., Wenzel, W.W., 2005. Rhizosphere geometry and heterogeneity arising from root-mediated physical and chemical processes (Review). New Phytologist 168, 293-303.
6. Levy, G.J., Mamedov, A.I. 2002. High-energy-moisture-characteristic aggregate stability as a predictor for seal. Soil Science Society of America Journal 66(5): 1603-1609.
7. Lipiec J., Walczak, R., Witkowska-Walczak, B., Nosalewicz, A., Słowinska-Jurkiewicz, A., Sławinski, C. 2007. The effect of aggregate size on water retention and pore structure of two silt loam soils of different genesis. Soil and Tillage Research 97(2): 239–246.
8. Mamedov A.I., Levy, G.J. 2013. High energy moisture characteristics: linking between some soil processes and structure stability. In: S. Logsdon, M. Berli, and R. Horn, (eds). Quantifying and Modeling Soil Structure Dynamics: Advances in Agricultural Systems Modeling. Trans-disciplinary Research, Synthesis, Modeling and Applications, vol. 3, SSSA, Inc. Madison, WI USA, pp.41-74.

9. Mamedov, A.I., Wagner, L.E., Huang, C., Norton, L.D., Levy, G.J., 2010. Polyacrylamide effects on aggregate and structure stability of soils with different cay mineralogy. Soil Science Society of America Journal 74(5): 1720-1732.
10. Mamedov, A.I., Bar-Yosef, B., Levkovich, I., Rosenberg, R., Silber, A., Fine, P., Levy, G.J., 2014. Amending soil with sludge, manure, humic acid, orthophosphate and phytic acid: Effects on aggregates stability. Soil Research 52(4): 317-326.
11. Pierson, F.B., Mulla, D.J., 1989. An improved method for measuring aggregate stability of a weakly aggregated loessial soil. Soil Science Society of America Journal 53(6): 1825-1831.
12. Pikul, J.J.L., Osborne, S., Ellsbury, M., Riedell, W., 2007. Particulate organic matter and water-stable aggregation of soil under contrasting management. Soil Science Society of America Journal 71(3): 766–776.
13. Porebska, D., Slawinski, C., Lamorski, K., Walczak, R.T., 2006. Relationship between van Genuchten’s parameters of the retention curve equation and physical properties of soil solid phase. International Agrophysics 20(2): 153–159.
14. Pulido Moncada, M., Gabriels, D., Cornelis, W., Lobo, D., 2015. Comparing aggregate stability tests for soil physical quality indicators. Land Degradation and Development 26(8): 843–852.
15. Rillig, M.C., Mummey, D.L., 2006. Mycorrhizas and soil structure: New Phytologist 171(1): 41-53.
16. Roger-Estrade, J., Richard, G., Dexter, A.R., Boizard, H., de Tourdonnet, S., Bertrand, M., Caneill, J., 2009. Integration of soil structure variations with time and space into models for crop management. A review. Agronomy for Sustainable Development 29(1): 135–142.
17. Shainberg, I., Mamedov, A.I., Levy, G.J., 2003. The role of wetting rate and rain energy in seal formation and interrill erosion. Soil Science 168(1): 54-62.
18. Strudley, M.W., Green, T.R., Ascough, J.C., 2008. Tillage effects on soil hydraulic properties in space and time: state of the science. Soil and Tillage Research 99(1): 4-48.
19. Uyanoz, R., Karaca, U., Karaarslan, E. 2012. Effects of wheat (Triticum Aestivum L.) variaties on soil properties in the rizosphere. Selcuk University Project Report. Konya, Turkey.
20. van Donk, S. J., Martin, D. L., Irmak, S., Melvin, S. R., Petersen, J. L., Davison, D. R. 2010. Crop residue cover effects on evaporation, soil water content, and yield of deficit-irrigated corn in west-central Nebraska. Transactions of the ASABE 53 (6): 1787-1797.
21. van Genuchten, M.Th. 1980. A closed form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Science Society of America Journal 44(5): 892–898.