Assessing the Effects of Solarization and Sodium Azide Amendments on Selected Soil Parameters, Enzyme Activities and Microbial Populations


Soil borne pathogens result in serious losses in yield of crops grown in the United States (US) and various parts of the world. One of the most effective chemicals used to control these pathogens was methyl bromide (CH3Br, MeBr), a pre-plant fumigant with a broad spectrum of activity. Sodium azide has been proposed in combination with solarization as a viable alternative to replace MeBr due to environmental concerns with respect to ozone depletion in the stratosphere and as a possible carcinogen. However, the possible impacts of sodium azide as a soil pollutant and its effect on soil biological processes have not been fully studied. In this study the effect of sodium azide used alone and in combination with solarization and mulching on selected soil enzyme activities (phosphomonoesterases, arylsulfatase and phosphodiesterase) were assessed. Responses of arylsulfatase and phosphodiesterase to solarization and mulching and azide treatment were found to be affected in the same way, suggesting a similar mode of action. Soil pH in control soils was significantly increased by azide application; however, in mulched soils, pH was decreased. The significant decrease in soil pH in mulched soils may be very important in explaining the increase in the acid phosphatase activity observed in mulched soils. Overall, solarization and sodium azide treatment significantly reduced both fungi and bacterial populations but the responses among the various treatments varied significantly.

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A. Kumi, V. Khan and R. Ankumah, "Assessing the Effects of Solarization and Sodium Azide Amendments on Selected Soil Parameters, Enzyme Activities and Microbial Populations," Journal of Environmental Protection, Vol. 4 No. 8, 2013, pp. 772-778. doi: 10.4236/jep.2013.48090.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] S. C. Wofsy, M. B. McElroy and Y. L. Yung, “The Chemistry of Atmospheric Bromine,” Geophysical Research Letters, Vol. 2, No. 6, 1975, pp. 215-218.
[2] M. J. Prather, M. B. McElroy and S. C. Wofsy, “Reductions in Ozone at High Concentrations of Stratospheric Halogens,” Nature, Vol. 312, No. 5991, 1984, pp. 227-231. doi:10.1038/312227a0
[3] S. Wilhelm, R. C. Storkan and J. E. Sagen, “Verticillium wilt of Strawberry Controlled by Fumigation of Soil with Chloropicrin and Chloropicrin-Methyl Bromide Mixtures,” Phytopathology, Vol. 51, 1961, pp. 744-748.
[4] J. J. Stapleton and J. E. DeVay, “Soil Solarization a Non-Chemical Approach for Management of Plant Pathogens and Pests,” Crop Protection, Vol. 5, No. 3, 1986, pp. 190-198. doi:10.1016/0261-2194(86)90101-8
[5] J. Katan, A. Greenberger, H. Alon and A. Grinstein, “Soil Solarization for Plant and Weed Control,” Proceedings of the 16th Congress of Mediterranean Phytopathological Union, Vol. 84, 1984, pp. 115-117.
[6] C. Stevens, V.A. Khan, J. E. Brown, G. J. Hochmuth, W. E. Splittstoesser and D. M. Granberry, “Plastic Chemistry and Technology as Related to Plastic Culture in Solar Heating,” Chapter 10, 1991, pp. 141-158.
[7] J. J. Stapleton and J. E. DeVay, “Soil Solarization: A Natural Mechanism of Integrated Pest Management,” In: R. Reuveni, Ed., Novel Approaches to Integrated Pest Management, Lewis Publishers, Boca Raton, 1995, pp. 309-322.
[8] R. Rodriguez-Kabana and J. R. Ackridge, “Sodium Azide [SEP-100] for the Control of Nematodes and Weed Problems in Green Pepper Production,” Proceedings of the Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, San Diego, 3-6 November 2003, p. 46.
[9] J. Katan, A. Greenberger, H. Alon and A. Grinstein, “Solar Heating by Polyethylene Mulching for the Control of Diseases Caused by Soil Borne Pathogens,” Phytopathology, Vol. 66, No. 5, 1976, pp. 683-688. doi:10.1094/Phyto-66-683
[10] M. A. Tabatabai and J. M. Bremner, “Use of p-Nitrophenyl Phosphate for Assay of Soil Phosphatase Activity,” Soil Biology & Biochemistry, Vol. 1, No. 4, 1969, pp. 301-307. doi:10.1016/0038-0717(69)90012-1
[11] M. G. Browman and M. A. Tabatabai, “Phosphodiesterase Activity of Soils,” Soil Science Society of America Journal, Vol. 42, No. 2, 1978, pp. 284-290. doi:10.2136/sssaj1978.03615995004200020016x
[12] M. A. Tabatabai and J. M. Bremner, “Factors Affecting Soil Arylsulphatase Activity,” Soil Science Society of America Journal, Vol. 34, No. 3, 1970, pp. 427-429. doi:10.2136/sssaj1970.03615995003400030023x
[13] E. A. Curl and R. Rodriguez-Kabana, “Herbicide-Plant Diseases Relationship,” In: E. D. Camper, Ed., Research Methods in Weed Science, 2nd Edition, Southern Weed Science Society, Las Cruces, 1986, pp. 429 -455.
[14] A. Walkley and C. A. Black, “A critical Examination of a Rapid Method of Determining Organic Carbon in Soils: Effects of Variations in Digestion Conditions and of Inorganic Constituents,” Soil Science, Vol. 63, No. 4, 1947, pp. 251-263. doi:10.1097/00010694-194704000-00001
[15] M. L. Peech, “Methods of Soil Analyses for Soil Fertility Investigations,” United States Department of Agriculture, Washington DC, 1947, p. 25.
[16] T. Greweling and M. L. Peech, “Chemical Soil Test,” Agriculture Experiment Station, Cornell University, 1960, Ithaca, p. 960.
[17] Statistical Analysis Software, SAS, Cary, 2000.
[18] D. S. Jenkinson, and D. S. Powlson, “The Effect of Biocidal Treatments on Metabolism in Soil. I. Fumigation with Chloroform,” Soil Biology & Biochemistry, Vol. 8, No. 3, 1976, pp. 167-177. doi:10.1016/0038-0717(76)90001-8
[19] M. Gennari, M. Negre and R. R. Ambrosoli, “Effects of Ethylene Oxide on Soil Microbial Content and Some Soil Chemical Characteristics,” Plant and Soil, Vol. 102, No. 2, 1987, pp. 197-200.

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