Comparison of normality test methods for some soil properties in the arid land of South Khorasan.

Document Type : Research Paper

Authors

1 Department of Rangeland and Watershed Management and Research Group of Drought and Climate Change, Faculty of Natural Resources and Environment, University of Birjand, Birjand, Iran.

2 Department of Soil Science, Research Group of Drought and Climate Change, Faculty of Agriculture, University of Birjand, Birjand, Iran.

Abstract

Statistical assumptions are the basis of many univariate and multivariate statistical tests. Normality is the most basic assumption of multivariate analysis in plant ecology. If the normality assumption is violated, some specific statistical tests are not valid. Therefore, the present study compares the methods of normality assessment of some soil properties in the arid land of South Khorasan. It also examines the effect of increasing the number of soil samples from 25 to 50 on the normality results. Histogram, box plot, Q-Q plot, CV, skewness, and univariate and multivariate normality tests were used. The results showed that EC, K, Ca, Mg, Na, Cl, HCO3, and SAR data had a very high variation (CV 75–100%) and saturation moisture and pH had a low variation (CV <15%). Based on the results of most statistical tests and the skewness coefficient, saturation moisture, pH, N, P, CaCO3, sand, and silt were normal. EC, K, Ca, Mg, Na, Cl, HCO3 and SAR had the right skewed distribution. The results showed multivariate normality was violated, and the use of these data was not suitable for multivariate analysis. The results of the goodness-of-fit test showed that P, sand, and silt follow a normal distribution. Other soil properties do not follow any of the studied probability distributions (p≥0.05). Therefore, the use of nonparametric is recommended for the physical and chemical properties of the soil in the area. Although in general, the increase in the number of samples has a positive effect on the actual distribution of the community, but due to the high spatial variability of some soil properties such as salinity, the status of nutrients, particle size, etc., the CV and the range of variations in most of soil properties are wide.

Keywords

References

References
Aggag A.M., and Alharbi A. 2022. Spatial Analysis of Soil Properties and Site-Specific Management Zone Delineation for the South Hail Region, Saudi Arabia. Sustainability. 14(23):16209.
Al-Kaisi M. M., Lal R., Olson K. R., and Lowery B. 2017. Fundamentals and Functions of Soil Environment. In: Al-Kaisi M. M. and Lowery B. (Ed.), Soil Health and Intensification of Agroecosystems (pp. 1-23). Elsevier Inc.
Amer, B.S., Moussa, K.F., Sheha, A.A. and Abdel-Fattah, M.K. 2021. Delineation of site-specific management zones using multivariate analysis and geographic information system technique. Plant Archives, 21: 1385–1390
Awal R, Safeeq M, Abbas F, Fares S, Deb SK, Ahmad A, Fares A. 2019. Soil Physical Properties Spatial Variability under Long-Term No-Tillage Corn. Agronomy. 9(11):750.
Awal R, Safeeq M., Abbas F., Fares S., Deb S.K., Ahmad A., and Fares A. 2019. Soil Physical Properties Spatial Variability under Long-Term No-Tillage Corn. Agronomy, 9(11):750.
Bagheri Bodaghabadi M. 2018. Is it necessarily a normally distributed data for kriging? A case study: soil salinity map of Ghahab area, central Iran. Desert, 23(2), 284-293.
Blanca M. J., Alarcón R., Arnau J., Bono R., and Bendayan R. 2017. Non-normal data: Is ANOVA still a valid option? Psicothema, 29(4): 552–557.
Carter M.R., and Gregorich E.G., Eds. 2008. Soil Sampling and Methods of Analysis. 2nd Edition, CRC Press, Taylor & Francis Group, Boca Raton. 1224 p.
Cooksey R. W. 2020 Descriptive Statistics for Summarizing Data. Illustrating Statistical Procedures: Finding Meaning in Quantitative Data, 61–139.
Froughifar H., Jafarzadah A.A., Torabi Gelsefidi H. and Aliasgharzadah, N. 2012. Effect of different landforms on spatial variability and frequency distribution of soil biological properties in Tabriz Plain. Water and Soil Science (Agricultural Science), 21(4): 35-52. (In Persian)
Fukumasu J., Jarvis N., Koestel J., Katterer T., and Larsbo M. 2022. Relations between soil organic carbon content and the pore size distribution for an arable topsoil with large variations in soil properties. European Journal of Soil Science, 73(1), e13212.
Gel Y.R., Miao W., and Gastwirth J.L. 2007. Robust directed tests of normality against heavy-tailed alternatives. Computational Statistics & Data Analysis, 51(5), 2734–2746.
Greenacre M.J., and Primicerio R. 2013. Multivariate analysis of ecological data. Fundación BBVA. 336 p.
Hair J.F., Black W.C., Babin B.J., and Anderson R.E. 2010. Multivariate Data Analysis. 7th Edition, Pearson, New York. 816 p.
Han J., Liu X., Wu Y., and Zhou X. 2020. Importance of Distribution Type on Bearing Capacity of an Embedded Foundation in Spatially Varying Soils. Advances in Civil Engineering, 1-15.
Hartemink A. E., Zhang Y., Bockheim J. G., Curi N., Silva S. H. G., Grauer-Gray J., Lowe D. J., and Krasilnikov P. 2020. Soil horizon variation: A review. In D. L. Sparks (Ed.), Advances in Agronomy (1 ed., Vol. 160, pp. 125-185). (Advances in Agronomy; Vol. 160, No. 1). Academic Press.
Hwang S. I., and Choi S. I. 2006. Use of a lognormal distribution model for estimating soil water retention curves from particle-size distribution data. Journal of Hydrology, 323(1-4): 325-334.
Jafari Haghighi M., 2003. Method of Soil Analysis sampling and Important Physical and Chemical Analysis with emphasis on theoretical and applied principles. Publication Nedaye zohi. 236 pp. (In Persian)
Jafari M., and Rostampour M. 2019. Soil - Plant Relationships: Ecology, Statistics and analysis (Vol. 1). University of Tehran Press, Tehran, 468 p. (In Persian)
Kent M. 2012. Vegetation Description and Data Analysis: A Practical Approach, 2nd Ed. Wiley-Blackwell, 448 p.
Khatun N. 2021. Applications of Normality Test in Statistical Analysis. Open Journal of Statistics, 11: 113-122.
Kim N. 2016. A robustified Jarque–Bera test for multivariate normality. Economics Letters, 140: 48-52.
Kim T. K., and Park J. H. 2019. More about the basic assumptions of t-test: normality and sample size. Korean journal of anesthesiology, 72(4): 331–335.
Knief U., and Forstmeier W. 2021. Violating the normality assumption may be the lesser of two evils. Behaviour Research, 53: 2576–2590.
Korkmaz, S. 2022. Package “MVN”. Multivariate Normality Tests. https://cran.r-project.org/web/packages/MVN/MVN.pdf
Legendre P., and L. Legendre 2012. Numerical ecology. Third edition. Elsevier, Amsterdam, The Netherlands. 853 p.
Li G., Wang M., Ma C., Tao R., Hou F., and Liu Y. 2021. Effects of Soil Heterogeneity and Species on Plant Interactions. Frontiers in Ecology and Evolution, 9:756344.
Li CH. 2021. Statistical estimation of structural equation models with a mixture of continuous and categorical observed variables. Behav Res 53, 2191–2213
Li X., Chen, Y., Lv G., Wang J., Jiang L., Wang H. and Yang X. 2022. Predicting spatial variability of species diversity with the minimum data set of soil properties in an arid desert riparian forest. Front. Plant Sci. 13:1014643.
Liu Y., Li G., Wang M., Yan W., and Hou F. 2021. Effects of three-dimensional soil heterogeneity and species composition on plant biomass and biomass allocation of grass-mixtures. AoB PLANTS, 13(4): plab033.
Liu Z., Al Amer F.M., Xiao M. Xu C., Furuya-Kanamori L., Hong H., Siegel L., and Lin L. 2023. The normality assumption on between-study random effects was questionable in a considerable number of Cochrane meta-analyses. BMC Medicine 21, 112.
Löfman M.S., Korkiala-Tanttu L.K. 2021. Inherent Variability of Geotechnical Properties for Finnish Clay Soils. In: Matos, J.C., et al. 18th International Probabilistic Workshop. IPW 2021. Lecture Notes in Civil Engineering, vol 153. Springer, Cham.
McGrath D., Zhang C. 2003. Spatial distribution of soil organic carbon concentrations in grassland of Ireland. Appl Geochem, 18:1629–1639.
Meyers L. S., Gamst G. C., and Guarino A. J. 2012. Applied Multivariate Research: Design and Interpretation. SAGE Publications, Inc. 1104 p.
Mishra P., Pandey C. M., Singh U., Gupta A., Sahu C., and Keshri A. 2019. Descriptive statistics and normality tests for statistical data. Annals of cardiac anaesthesia, 22(1): 67–72.
Moharana P.C., Jena R.K., Kumar N., Singh R.S., and Rao S.S. 2021. Assessment of soil organic and inorganic carbon stock at different soil depths after conversion of desert into arable land in the hot arid regions of India. Carbon Manag, 12, 153–165.
Nunes F. C., Lander A., Claudia C., Eduardo G., Thaís S., and Prasad M. N. V. 2020. Chapter 9 - Soil as a complex ecological system for meeting food and nutritional security. In: Prasad, M. N. V., Pietrzykowski, M. (Eds.) Climate Change and Soil Interactions. Elsevier. 229-269.
Obi J. C., Udoh İ. B., and Obi İ. C. 2020. Modelling soil properties from horizon depth functions and terrain attributes: An example with cation exchange capacity. Eurasian Journal of Soil Science, 9(1), 10-17.
Oppong F. B., and Agbedra S. Y. 2016. Assessing Univariate and Multivariate Normality, a Guide for Non-Statisticians. Mathematical Theory and Modeling, 6(2): 26-33.
Piotrowska-Długosz A., Breza-Boruta B. and Długosz J. 2019. Spatio-temporal heterogeneity of soil microbial properties in a conventionally managed arable field. J Soils Sediments 19, 345–355.
R Core Team, 2021. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-project.org/.
Razali N., and Yap B. W. 2011. Power Comparisons of Shapiro-Wilk, Kolmogorov-Smirnov, Lilliefors and Anderson-Darling tests. Journal of Statistical Modeling and Analytics, 2: 21-33.
Rostampour M. 2022. Rangeland ecosystems monitoring in different climatic regions of Iran, South Khorasan Province, Zirkouh site. Research Institute of Forests and Rangelands, Tehran, Iran. (In Persian).
Schoder V., Himmelmann A., and Wilhelm K. P. 2006. Preliminary testing for normality: some statistical aspects of a common concept. Clinical and experimental dermatology, 31(6): 757–761.
Šestak I., Pereira P., Telak L.J., Perčin A., Hrelja I., Bogunović I. 2022. Soil Chemical Properties and Fire Severity Assessment Using VNIR Proximal Spectroscopy in Fire-Affected Abandoned Orchard of Mediterranean Croatia. Agronomy. 12(1):129.
Shukla M.K., and Sharma P. 2023. Fuzzy K-Means and Principal Component Analysis for Classifying Soil Properties for Efficient Farm Management and Maintaining Soil Health. Sustainability. 15(17):13144.
Tsagris M., and Pandis N. 2021. Normality test: Is it really necessary? American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics, 159(4): 548–549.
Weine E., McPeek M. S., and Abney M. 2023. Application of Equal Local Levels to Improve Q-Q Plot Testing Bands with R Package qqconf. Journal of statistical software, 106(10), 10.
Wulandari D., Sutrisno S., and Nirwana, M. B. 2021. Mardia’s Skewness and Kurtosis for Assessing Normality Assumption in Multivariate Regression. Enthusiastic: International Journal of Applied Statistics and Data Science, 1(1): 1–6.
Yang S., and Berdine G. 2021. Normality tests. The Southwest Respiratory and Critical Care Chronicles, 9(37):87–90.
Yap B.W., and Sim C.H. 2011. Comparisons of Various Types of Normality Tests. Journal of Statistical Computation and Simulation, 81: 2141-2155.
Zhang L., Mi X., Harrison R. D., Yang B., Man X., and Ren H. 2020. Resource heterogeneity, not resource quantity, plays an important role in determining tree species diversity in two species-rich forests. Frontiers in Ecology and Evolution, 8:224.
Zhou M., and Shao Y. 2014. A Powerful Test for Multivariate Normality. Journal of applied statistics, 41(2): 351–363.
Desert
Volume 28, Issue 2
December 2023
Pages 381-402

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