Soil hydraulic properties as affected by Vetiver and Polyacrylamide

Document Type : Complete scientific research article

Authors

1 Associate Professor, Department of Soil Science, Faculty of Agriculture, Ferdowsi University of Mashhad

2 Professor, Dept. of Soil Science, Isfahan University of Technology

Abstract

Background and Objectives: Suitable land management result in improving the soil hydro-physical properties and erosion control in arid and semi-arid regions. Application the cover crop as bioengineering tool is a good choice to improve soil hydro-physical properties and to protect the soil against erosive factors. Anionic polyacrylamide (PAM) has been widely used in this field, as well. In literature, the individual effect of Vetiver and PAM on Soil structural stability and erosion indices has been investigated. The objective of this study was to investigate and compare the effect of vetiver cultivation system, PAM and their combination on hydraulic properties and physical quality index of soil in experimental plots.
Materials and Methods: This study was performed in loamy soil plots of a loamy soil in Agriculture Campus, Ferdowsi University of Mashhad. The experimental treatments include vetiver cultivation (VP0), PAM (20 (P2) and 40 (P4) kg ha-1), simultaneous application of vetiver and PAM concentrations (VP2, and VP4). In addition, P0 (no PAM and vetiver) was regarded as control treatment. The soil moisture contents for different treatments were measured at 0, 5, 10, 50, 100, 300, 500, 1000, and 1500 kPa. According to this data the van Genuchten’s equation was fitted to the soil moisture characteristic curve using the RETC software, and the parameters of model were estimated by the least square error methods. Also, saturated hydraulic conductivity and soil physical quality index were determined. This study was designed based on randomized complete blocks in a factorial arrangement with 3 replications. Data of van Genuchten’s parameters, Sgi index, and Ks were analyzed using SPSS 23 software.
Results: The results showed that vetiver and PAM through increasing the aggregation and stability of soil structure, and improving the structural properties increased θs, and ks. However, the effect of PAM on ks depends on its concentration and viscosity. Vetiver decreased θr, and the hydrophilic molecules of PAM polymer increased θr. Vetiver increased considerably the value of α parameter and decreased air entry value by increasing the soil macro-pores. Although, the value of α parameter was not affected by PAM. Vetiver increased the value of n parameter, while PAM decreased its value. Also, vetiver and PAM increased the Sgi through the aggregation and improving the soil structure and physical condition. In general, vetiver had more effect on parameters of van Genuchten model and improvement of soil hydraulic properties than the PAM and the combination of vetiver and PAM showed the greatest effect.
Conclusion: Generally, the results of this research indicated that the very low cost and long-term bioengineering technique based on vetiver system can be recommended to improve physical and structural properties of soil in semi-arid regions such as Iran.

Keywords


1.Abedi-Koupai, J., Sohrab, F., and Swarbrick, G.E. 2008. Evaluation of hydrogel application
on soil water retention characteristics. J. Plant Nutr. 31: 2. 317-331.
2.Amiri, E., Emami, H., Astaraei, A.R., and Mosaddeghi, M.R. 2017. Comparing the Effects of
Vetiver and Polyacrylamide on Soil Structural Stability and Erosion Indices. Environmental
Erosion Researches. 23: 3.71-90. (In Persian)
3.Amiri, E., Emami, H., Mosaddeghi, M.R., and Astaraei, A.R. 2017. Investigating the effect of
vetiver and polyacrylamide on runoff, sediment load and cumulative water infiltration.
Soil Research. 55: 769-777.
4.Ao, C., Yang, P., Ren, S., Xing, W., Li, X., and Feng, X. 2016. Efficacy of granular
polyacrylamide on runoff, erosion and nitrogen loss at loess slope under rainfall simulation.
Environmental Earth Sciences. 75: 490-590.
5.Bryan, R.B. 1992. The influence of some soil conditioners on soil properties: laboratory tests
on Kenyan soil samples. Soil Technology. 5: 225-247.
6.Calonego, J.C., and Rosolem, C.A. 2011. Soil water retention and s index after crop rotation
and chiseling. Revista Brasileira de Ciência do Solo. 35: 1927-1937.
7.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.
8.Edem, I.D., and Okoko, P. 2015. Pedo-transfer function of saturated hydraulic conductivity
and soil loss under vetiver alleys for soil fertility and aggregation. Inter. J. Plant Soil Sci.
4: 5. 461-474.
9.Emami, H., and Astaraei, A.R. 2012. Effect of Organic and Inorganic Amendments on
Parameters of Water Retention Curve, Bulk Density and Aggregate Diameter of a Salinesodic
Soil. J. Agric. Sci. Technol. 14: 1625-1636.
10.Guber, A.X., Rawls, W.J., Shein, E.V., and Pachepsky, Y.A. 2003. Effect of soil aggregate
size distribution on water retention. Soil Science. 168: 223-233.
11.Kern, J.S. 1995. Evaluation of soil water retention models based on basic soil physical
properties. Soil Sci. Soc. Amer. J. 59: 1134-1141.
12.Klute, A., and Dirksen, C. 1986. Hydraulic conductivity and diffusivity: laboratory methods.
P 687-732, In: A. Klute (Ed.), Methods of Soil Analysis. Part 1. SSSA/ASA. Madison, WI.
13.Lentz, R.D. 2015. Polyacrylamide and biopolymer effects on flocculation, aggregate stability
and water seepage in a silt loam. Geoderma. 241-242: 289-294.
14.Levey, G.Y., Levin, J., Gal, M., Ben-Hur, M., and Shainberg, I. 1992. Polymers effects on
infiltration and soil erosion during consecutive simulated sprinkler irrigations. Soil Sci. Soc.
Amer. J. 56: 902-907.
15.Lipiec, J., Walczak, R., Witkowska-Walczak, B., Nosalewicz, A., Słowińska Jurkiewicz, A.,
and 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: 239-246.
16.Mamedov, A.I., Huang, C.H., Aliev, F.A., and Levy, G.J. 2016. Aggregate stability and
water retention near saturation characteristics as affected by soil texture, aggregate size and
polyacrylamide application. Land Degrad. Develop. Published online in Wiley Online
Library.
17.Materechera, S. 2010. Soil physical and biological properties as influenced by growth of
vetiver grass (Vetiveria zizanioides L.) in a semi-arid environment of South Africa Simeon.
19th World Congress of Soil Science, Soil Solutions for a Changing World. 1-6 August
2010, Brisbane, Australia. Published on DVD.
18.Melo, D.V.M.SD., de Almeida, B.G., Andrade, K.R., de Souza, E.R., Souza, W.L., da Silva
Souza, W.L., and de Almeida, C.D.G.C. 2016. Pore size distribution and hydro-physical
properties of cohesive horizons treated with anionic polymer. Afric. J. Agric. Res.
11: 44. 4444-4453.
19.Oku, E., Fagbola, O., and Troung, P. 2011. Evaluation of vetiver grass buffer strips and
organomineral fertilization for the improvement of soil physical properties. Kasetsart J.
(Natural Science). 45: 824-831.
20.Porebska, D., Slawinski, C., Lamorski, K., and 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: 153-159.
21.Sojka, R.E., Bjorneberg, D.L., Entry, J.A., Lentz, R.D., and Orts, W.J. 2006. Polyacrylamide
in agriculture and environmental land management. Advances in Agronomy. 92: 75-162.
22.Tormena, C.A., da Silva, A.P., Imhoff, S.D.C., and Dexter, A.R. 2008. Quantification of the
soil physical quality of a tropical Oxisol using the S index. Scientia Agricola. 65: 56-60.
23.Truong, P.N. 2002. Vetiver grass technology. P 114-132, In: M. Maffei (Ed.), Vetiveria.
Taylor and Francis: London and New York.
24.Van Genuchten, M.T. 1980. A closed form equation for predicting the hydraulic conductivity
of unsaturated soils. Soil Sci. Soc. Amer. J. 44: 892-898.