Eurasian Journal of Soil Science

Abstract

Cadmium (Cd) contamination poses a significant threat to soil health and agricultural productivity, particularly under varying water availability and soil textures. This study examines the effects of water levels (25%, 50%, 75%, and 100% field capacity) and soil textures (sandy clay loam, silty loam, and clay) on key microbiological properties, including basal soil respiration (BSR), microbial biomass carbon (Cmic), dehydrogenase activity (DHA), and catalase activity (CA), in Cd-contaminated soils. An incubation experiment was conducted under controlled conditions at 20 ± 0.5°C for 10 days. Microbiological properties were assessed using standard methods: alkali absorption for BSR, substrate-induced respiration for Cmic, spectrophotometric assays for DHA, and volumetric determination for CA. Optimal microbial activity across all parameters was observed at 75% field capacity, highlighting the importance of balanced soil moisture. Clay soils consistently exhibited the highest activity due to their superior organic matter content and buffering capacity, while sandy clay loam soils showed the lowest activity due to limited water retention and nutrient availability. Excessive moisture at 100% field capacity reduced oxygen diffusion, suppressing microbial activity, while insufficient moisture at 25% field capacity constrained microbial metabolism. These findings provide critical insights into the interplay between soil texture, water availability, and Cd contamination, offering valuable guidance for sustainable soil and water management practices to mitigate heavy metal toxicity in agricultural systems.

Keywords

Cadmium contamination, soil microbiology, water levels, soil texture, enzymatic activity.

References

<p>Akbar, K.F., Hale, W.H.G., Headley, A.D., Athar, M., 2006. Heavy metal contamination of roadside soils of northern England. <em>Soil and Water Research</em> 1(4): 158-163.</p>

<p>Anderson, J.P.E., 1982. Soil respiration. In. Methods of soil analysis, Part 2- Chemical and Microbiological Properties. Page, A.L., Keeney, D. R., Baker, D.E., Miller, R.H., Ellis, R. Jr., Rhoades, J.D. (Eds.). ASA-SSSA, Madison, Wisconsin, USA. pp. 831-871.</p>

<p>Anderson, J.P.E., Domsch, K.H., 1978. A physiological method for the quantative measurement of microbial biomass in soils. <em>Soil Biology and Biochemistry</em> 10: 215 &ndash; 221.</p>

<p>Babayeva,&nbsp;T.,&nbsp;Guliyev,&nbsp;A.,&nbsp;İslamzade,&nbsp;T.,&nbsp;İslamzade,&nbsp;R.,&nbsp;Haciyeva,&nbsp;X.,&nbsp;Ashurova,&nbsp;N.,&nbsp;Aliyeva,&nbsp;A.,&nbsp;Maksudov,&nbsp;S.,&nbsp;2024. Impacts of irrigation with Cd-contaminated water from Sugovushan Reservoir, Azerbaijan on total cadmium and its fractions in soils with varied textures. <em>Eurasian Journal of Soil Science</em> 13(2): 145-152.</p>

<p>Bayraklı, B., Dengiz, O., 2019. Determination of heavy metal risk and their enrichment factor in intensive cultivated soils of Tokat Province. <em>Eurasian Journal of Soil Science</em> 8(3): 249-256.</p>

<p>Beck, T.H., 1971. Die Messung derkKatalasen aktivit&auml;t Von B&ouml;den. <em>Zeitschrift f&uuml;r Pflanzenern&auml;hrung und Bodenkunde</em> 130(1): 68-81.</p>

<p>Bouyoucos, G.J., 1962. Hydrometer method improved for making particle size analyses of soils. <em>Agronomy Journal</em> 54(5): 464-465.</p>

<p>Bower, C.A., Wilcox L.V., 1965. Soluble Salts. In: Methods of soil analysis. Part 2. Chemical and microbiological properties. Black, C.A., Evans, D.D., White, J.L., Ensminger, L.E., Clark F.E. (Eds.). Soil Science Society of America. Madison, Wisconsin, USA. pp. 933-951.</p>

<p>Chebyshev, N., Chebyshev N., Ansabayeva, A., Mironova, E., Kazak, A., 2024. The Distribution of Fusarium in Barley Crops: PCR. <em>Polish Journal of Environmental Studies</em> 33(2): 1559 &ndash; 1568.</p>

<p>Chen, Y., Liu, Q., Liu, Y., Jia, F.A., He, X.H., 2014. Responses of soil microbial activity to cadmium pollution and elevated CO2. <em>Scientific Reports</em> 4: 4287.</p>

<p>Effron, D., de la Horra, A.M., Defrieri, R.L., Fontanive, V., Palma, R.M., 2004. Effect of cadmium, copper, and lead on different enzyme activities in a native forest soil. <em>Communications in Soil Science and Plant Analysis</em> 35(9-10): 1309-1321.</p>

<p>EN 13656, 2002. Characterization of waste: microwave-assisted digestion with hydrofluoric (HF), nitric (HNO3), and hydrochloric (HCl) acid mixture for subsequent determination of elements. EN Standards. Available at&nbsp; [Access date : 11.09.2023]: http://en-standards.standardsdirect.org/</p>

<p>FAO, 1985. Water Quality for Agriculture. Food and Agriculture Organization,&nbsp;Rome, Italy. Available at&nbsp; [Access date : 11.09.2023]: http://www.fao.org/3/T0234E/T0234E00.htm&nbsp;</p>

<p>Holmgren, G.G.S., Meyer, M.W., Chaney, R.L., Daniels, R.B., 1993. Cadmium, lead, zinc, copper, and nickel in agricultural soils of the United States of America. <em>Journal of Environmental Quality</em> 22(2): 335&ndash;348.</p>

<p>İslamzade, T., Baxishov, D., Guliyev, A., Kızılkaya, R., İslamzade, R., Ay, A., Huseynova, S., Mammadova, M., 2024. Soil fertility status, productivity challenges, and solutions in rice farming landscapes of Azerbaijan. <em>Eurasian Journal of Soil Science</em> 13(1): 70 - 78.</p>

<p>Joimel, S., Cortet, J., Jolivet, C.C., Saby, N.P.A., Chenot, E.D., Branchu, P., Consal&egrave;s, J.N., Lefort, C., Morel, J.L., Schwartz, C., 2016. Physico-chemical characteristics of topsoil for contrasted forest, agricultural, urban and industrial land uses in France. <em>Science of The Total Environment</em> 545-564: 40&ndash;47.</p>

<p>Kandziora-Ciupa, M., Ciepał, R., Nadg&oacute;rska-Socha, A., 2016. Assessment of heavy metals contamination and enzymatic activity in pine forest soils under different levels of anthropogenic stress. <em>Polish Journal of Environmental Studies</em> 25(3): 1045-1051.</p>

<p>Karaca, A., &Ccedil;etin, S.C., Turgay, O.C., Kızılkaya, R., 2011. Soil enzymes as indication of soil quality. In: Soil Enzymology, Soil Biology. Girish, S.,&nbsp; Varma, A. (Eds.), Vol 22, pp.119-148. Springer-Verlag Berlin Heidelberg.</p>

<p>Kızılkaya, R., Aşkın, T., 2002. Influence of cadmium fractions on microbiological properties in Bafra plain soils. <em>Archives of Agronomy and Soil Science</em> 48(3): 263-272.</p>

<p>Kızılkaya, R., Aşkın, T., Bayraklı, B., Sağlam, M., 2004. Microbiological characteristics of soils contaminated with heavy metals. <em>European Journal of Soil Biology</em> 40(2): 95-102.</p>

<p>Kızılkaya, R., Bayraklı, B., 2005. Effects of N-enriched sewage sludge on soil enzyme activities. <em>Applied Soil Ecology</em> 30(3): 192-202.</p>

<p>Kloke, A., 1980. Orientierungsdaten f&uuml;r tolerierbare Gesamtgehalte einiger Elemente in Kulturboden. Mitteilungen VDLUFA 1/III : 9 &ndash; 11 .</p>

<p>Klute, A., 1965. Water Capacity. In: Methods of Soil Analysis: Part 1 Physical and Mineralogical Properties, Including Statistics of Measurement and Sampling. Black, C.A., Evans, D.D., White, J.L., Ensminger, L.E., Clark F.E. (Eds.), Soil Science Society of America. Madison, Wisconsin, USA. pp. 273-278.</p>

<p>Li, Q., Hu, Q., Zhang,C., Jin, Z., 2018. Effects of Pb, Cd, Zn, and Cu on soil enzyme activity and soil properties related to agricultural land-use practices in karst area contaminated by Pb-Zn tailings. <em>Polish Journal of Environmental Studies </em>27(6): 2623-2632.</p>

<p>Lindsay, W.L., Norvell, W.A., 1978. Development of a DTPA soil test for zinc, iron, manganese, and copper. <em>Soil Science Society of America Journal</em> 42(3): 421-428.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p>

<p>Liu, J., Li, X., Zhu, Q., Zhou, J., Shi, L., Lu, W., Bao, L., Meng, L., Wu, L., Zhang, N., Christie, P., 2024. Differences in the activities of six soil enzymes in response to cadmium contamination of paddy soils in high geological background areas. <em>Environmental Pollution</em> 346: 123704.</p>

<p>Liu, P., Chen, S., Cui, Y., Tan, W., 2021. Insights into the inhibition effects of Cd on soil enzyme activities: From spatial microscale to macroscale. <em>Journal of Hazardous Materials</em> 418: 126274.</p>

<p>Mandzhieva&nbsp;,&nbsp;S.,&nbsp;Minkina,&nbsp;T.,&nbsp;Pinskiy,&nbsp;D.,&nbsp;Bauer,&nbsp;T.,&nbsp;Sushkova,&nbsp;S.,&nbsp;2014. The role of soil&#39;s particle-size fractions in the adsorption of heavy metals. <em>Eurasian Journal of Soil Science</em> 3(3): 197 - 205.</p>

<p>Moreno, J., Hern&aacute;ndez, T., Garcia, C., 1999. Effects of cadmium-contaminated sewage sludge compost on dynamics of organic matter and microbial activity in an arid soil. <em>Biology and Fertility of Soils</em> 28: 230&ndash;237.</p>

<p>Naidu, R., Kookana, R.S., Rogers, S., Bolan, N.S., Adriano, D., 2003. Bioavailability of metals in the soil&ndash;plant environment and its potential role in risk assessment. In: Bioavailability, Toxicity, and Risk Relationships in Ecosystems. Naidu, R., Gupta, V.V.S.R., Rogers, S., Kookana, R.S., Bolan, N.S., Adriano, D., (Eds.). Science Publishers, Inc., Enfield, New Hampshire, pp.46 &ndash;81.</p>

<p>Naidu, R., Kookana, R.S., Sumner, M.E., Harter, R.D., Tiller, K.G., 1997. Cadmium sorption and transport in variable charge soils: A Review. <em>Journal of Environmental Quality</em> 26: 602&ndash;617.</p>

<p>Naidu, R., Megharaj, M., Krishnamurti, G.S.R., Vig, K., Kookana, R.S., 2000. Bioavailability, definition and analytical techniques for assessment and remediation of contaminated (inorganic and organic) soils. In: Johnston, C.D., (Ed.), Contaminated site remediation: From Source Zones to Ecosystems. Proceedings of the 2000 Contaminated Site Remediation Conference, Melbourne, Australia, 283&ndash;290.</p>

<p>Page, A.L., Chang, A.C., El-Amamy, M., 1987. Cadmium levels in soils and crops in the United States. In: Lead, Mercury, Cadmium and Arsenic in the Environment. Hutchinson, T.C., Meema, K.M. (Eds.). John Wiley &amp; Sons Ltd. New York, pp. 119&ndash;146.</p>

<p>Peech, M., 1965. Hydrogen-Ion Activity. In: Methods of soil analysis. Part 2. Chemical and microbiological properties. Black, C.A., Evans, D.D., White, J.L., Ensminger, L.E., Clark F.E. (Eds.), Soil Science Society of America. Madison, Wisconsin, USA. pp. 914-926.</p>

<p>Pepper, I.L., Gerba, C.P., Brendecke, J.W., 1995. Environmental microbiology: a laboratory manual. Academic Press Inc. New York, USA.</p>

<p>Peters, D.B., 1965. Water Availability. In: Methods of Soil Analysis: Part 1 Physical and Mineralogical Properties, Including Statistics of Measurement and Sampling. Black, C.A., Evans, D.D., White, J.L., Ensminger, L.E., Clark F.E. (Eds.), Soil Science Society of America. Madison, Wisconsin, USA. pp. 279-285.</p>

<p>Rowell, D.L., 1996. Soil Science: methods and applications. Longman, UK. 350p.</p>

<p>Tan, X., Kong, L., Yan, H., Wang, Z., He, W., Wei, G., 2014. Influence of soil factors on the soil enzyme inhibition by Cd. <em>Acta Agriculturae Scandinavica, Section B &mdash; Soil &amp; Plant Science</em> 64(8): 666-674.</p>

<p>US Salinity Laboratory Staff, 1954. Diagnosis and improvement of saline and alkali soils. US Department of Agriculture Handbook 60, Washington, DC.</p>

<p>Vig, K., Megharaj, M., Sethunathan, N., Naidu, R., 2003. Bioavailability and toxicity of cadmium to microorganisms and their activities in soil: a review. <em>Advances in Environmental Research</em> 8(1): 121&ndash;135.</p>

<p>Walkley, A., Black, C.A., 1934. An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. <em>Soil Science</em> 37(1): 29&ndash;38.</p>

<p>Yeboah, J.O., Shi, G., Shi, W., 2021. Effect of heavy metal contamination on soil enzymes activities. <em>Journal of Geoscience and Environment Protection</em> 9: 135-154.</p>

<p>Zhang, R., Zhang, H., Yang, C., Li, H., Wu, J., 2024. Effects of water stress on nutrients and enzyme activity in rhizosphere soils of greenhouse grape. <em>Frontiers in Microbiology</em> 15:1376849.</p>

Abstract

Cadmium (Cd) contamination poses a significant threat to soil health and agricultural productivity, particularly under varying water availability and soil textures. This study examines the effects of water levels (25%, 50%, 75%, and 100% field capacity) and soil textures (sandy clay loam, silty loam, and clay) on key microbiological properties, including basal soil respiration (BSR), microbial biomass carbon (Cmic), dehydrogenase activity (DHA), and catalase activity (CA), in Cd-contaminated soils. An incubation experiment was conducted under controlled conditions at 20 ± 0.5°C for 10 days. Microbiological properties were assessed using standard methods: alkali absorption for BSR, substrate-induced respiration for Cmic, spectrophotometric assays for DHA, and volumetric determination for CA. Optimal microbial activity across all parameters was observed at 75% field capacity, highlighting the importance of balanced soil moisture. Clay soils consistently exhibited the highest activity due to their superior organic matter content and buffering capacity, while sandy clay loam soils showed the lowest activity due to limited water retention and nutrient availability. Excessive moisture at 100% field capacity reduced oxygen diffusion, suppressing microbial activity, while insufficient moisture at 25% field capacity constrained microbial metabolism. These findings provide critical insights into the interplay between soil texture, water availability, and Cd contamination, offering valuable guidance for sustainable soil and water management practices to mitigate heavy metal toxicity in agricultural systems.

Keywords: Cadmium contamination,  soil microbiology, water levels, soil texture, enzymatic activity.

References

Akbar, K.F., Hale, W.H.G., Headley, A.D., Athar, M., 2006. Heavy metal contamination of roadside soils of northern England. Soil and Water Research 1(4): 158-163.

Anderson, J.P.E., 1982. Soil respiration. In. Methods of soil analysis, Part 2- Chemical and Microbiological Properties. Page, A.L., Keeney, D. R., Baker, D.E., Miller, R.H., Ellis, R. Jr., Rhoades, J.D. (Eds.). ASA-SSSA, Madison, Wisconsin, USA. pp. 831-871.

Anderson, J.P.E., Domsch, K.H., 1978. A physiological method for the quantative measurement of microbial biomass in soils. Soil Biology and Biochemistry 10: 215 – 221.

Babayeva, T., Guliyev, A., İslamzade, T., İslamzade, R., Haciyeva, X., Ashurova, N., Aliyeva, A., Maksudov, S., 2024. Impacts of irrigation with Cd-contaminated water from Sugovushan Reservoir, Azerbaijan on total cadmium and its fractions in soils with varied textures. Eurasian Journal of Soil Science 13(2): 145-152.

Bayraklı, B., Dengiz, O., 2019. Determination of heavy metal risk and their enrichment factor in intensive cultivated soils of Tokat Province. Eurasian Journal of Soil Science 8(3): 249-256.

Beck, T.H., 1971. Die Messung derkKatalasen aktivität Von Böden. Zeitschrift für Pflanzenernährung und Bodenkunde 130(1): 68-81.

Bouyoucos, G.J., 1962. Hydrometer method improved for making particle size analyses of soils. Agronomy Journal 54(5): 464-465.

Bower, C.A., Wilcox L.V., 1965. Soluble Salts. In: Methods of soil analysis. Part 2. Chemical and microbiological properties. Black, C.A., Evans, D.D., White, J.L., Ensminger, L.E., Clark F.E. (Eds.). Soil Science Society of America. Madison, Wisconsin, USA. pp. 933-951.

Chebyshev, N., Chebyshev N., Ansabayeva, A., Mironova, E., Kazak, A., 2024. The Distribution of Fusarium in Barley Crops: PCR. Polish Journal of Environmental Studies 33(2): 1559 – 1568.

Chen, Y., Liu, Q., Liu, Y., Jia, F.A., He, X.H., 2014. Responses of soil microbial activity to cadmium pollution and elevated CO2. Scientific Reports 4: 4287.

Effron, D., de la Horra, A.M., Defrieri, R.L., Fontanive, V., Palma, R.M., 2004. Effect of cadmium, copper, and lead on different enzyme activities in a native forest soil. Communications in Soil Science and Plant Analysis 35(9-10): 1309-1321.

EN 13656, 2002. Characterization of waste: microwave-assisted digestion with hydrofluoric (HF), nitric (HNO3), and hydrochloric (HCl) acid mixture for subsequent determination of elements. EN Standards. Available at  [Access date : 11.09.2023]: http://en-standards.standardsdirect.org/

FAO, 1985. Water Quality for Agriculture. Food and Agriculture Organization, Rome, Italy. Available at  [Access date : 11.09.2023]: http://www.fao.org/3/T0234E/T0234E00.htm 

Holmgren, G.G.S., Meyer, M.W., Chaney, R.L., Daniels, R.B., 1993. Cadmium, lead, zinc, copper, and nickel in agricultural soils of the United States of America. Journal of Environmental Quality 22(2): 335–348.

İslamzade, T., Baxishov, D., Guliyev, A., Kızılkaya, R., İslamzade, R., Ay, A., Huseynova, S., Mammadova, M., 2024. Soil fertility status, productivity challenges, and solutions in rice farming landscapes of Azerbaijan. Eurasian Journal of Soil Science 13(1): 70 - 78.

Joimel, S., Cortet, J., Jolivet, C.C., Saby, N.P.A., Chenot, E.D., Branchu, P., Consalès, J.N., Lefort, C., Morel, J.L., Schwartz, C., 2016. Physico-chemical characteristics of topsoil for contrasted forest, agricultural, urban and industrial land uses in France. Science of The Total Environment 545-564: 40–47.

Kandziora-Ciupa, M., Ciepał, R., Nadgórska-Socha, A., 2016. Assessment of heavy metals contamination and enzymatic activity in pine forest soils under different levels of anthropogenic stress. Polish Journal of Environmental Studies 25(3): 1045-1051.

Karaca, A., Çetin, S.C., Turgay, O.C., Kızılkaya, R., 2011. Soil enzymes as indication of soil quality. In: Soil Enzymology, Soil Biology. Girish, S.,  Varma, A. (Eds.), Vol 22, pp.119-148. Springer-Verlag Berlin Heidelberg.

Kızılkaya, R., Aşkın, T., 2002. Influence of cadmium fractions on microbiological properties in Bafra plain soils. Archives of Agronomy and Soil Science 48(3): 263-272.

Kızılkaya, R., Aşkın, T., Bayraklı, B., Sağlam, M., 2004. Microbiological characteristics of soils contaminated with heavy metals. European Journal of Soil Biology 40(2): 95-102.

Kızılkaya, R., Bayraklı, B., 2005. Effects of N-enriched sewage sludge on soil enzyme activities. Applied Soil Ecology 30(3): 192-202.

Kloke, A., 1980. Orientierungsdaten für tolerierbare Gesamtgehalte einiger Elemente in Kulturboden. Mitteilungen VDLUFA 1/III : 9 – 11 .

Klute, A., 1965. Water Capacity. In: Methods of Soil Analysis: Part 1 Physical and Mineralogical Properties, Including Statistics of Measurement and Sampling. Black, C.A., Evans, D.D., White, J.L., Ensminger, L.E., Clark F.E. (Eds.), Soil Science Society of America. Madison, Wisconsin, USA. pp. 273-278.

Li, Q., Hu, Q., Zhang,C., Jin, Z., 2018. Effects of Pb, Cd, Zn, and Cu on soil enzyme activity and soil properties related to agricultural land-use practices in karst area contaminated by Pb-Zn tailings. Polish Journal of Environmental Studies 27(6): 2623-2632.

Lindsay, W.L., Norvell, W.A., 1978. Development of a DTPA soil test for zinc, iron, manganese, and copper. Soil Science Society of America Journal 42(3): 421-428.     

Liu, J., Li, X., Zhu, Q., Zhou, J., Shi, L., Lu, W., Bao, L., Meng, L., Wu, L., Zhang, N., Christie, P., 2024. Differences in the activities of six soil enzymes in response to cadmium contamination of paddy soils in high geological background areas. Environmental Pollution 346: 123704.

Liu, P., Chen, S., Cui, Y., Tan, W., 2021. Insights into the inhibition effects of Cd on soil enzyme activities: From spatial microscale to macroscale. Journal of Hazardous Materials 418: 126274.

Mandzhieva , S., Minkina, T., Pinskiy, D., Bauer, T., Sushkova, S., 2014. The role of soil's particle-size fractions in the adsorption of heavy metals. Eurasian Journal of Soil Science 3(3): 197 - 205.

Moreno, J., Hernández, T., Garcia, C., 1999. Effects of cadmium-contaminated sewage sludge compost on dynamics of organic matter and microbial activity in an arid soil. Biology and Fertility of Soils 28: 230–237.

Naidu, R., Kookana, R.S., Rogers, S., Bolan, N.S., Adriano, D., 2003. Bioavailability of metals in the soil–plant environment and its potential role in risk assessment. In: Bioavailability, Toxicity, and Risk Relationships in Ecosystems. Naidu, R., Gupta, V.V.S.R., Rogers, S., Kookana, R.S., Bolan, N.S., Adriano, D., (Eds.). Science Publishers, Inc., Enfield, New Hampshire, pp.46 –81.

Naidu, R., Kookana, R.S., Sumner, M.E., Harter, R.D., Tiller, K.G., 1997. Cadmium sorption and transport in variable charge soils: A Review. Journal of Environmental Quality 26: 602–617.

Naidu, R., Megharaj, M., Krishnamurti, G.S.R., Vig, K., Kookana, R.S., 2000. Bioavailability, definition and analytical techniques for assessment and remediation of contaminated (inorganic and organic) soils. In: Johnston, C.D., (Ed.), Contaminated site remediation: From Source Zones to Ecosystems. Proceedings of the 2000 Contaminated Site Remediation Conference, Melbourne, Australia, 283–290.

Page, A.L., Chang, A.C., El-Amamy, M., 1987. Cadmium levels in soils and crops in the United States. In: Lead, Mercury, Cadmium and Arsenic in the Environment. Hutchinson, T.C., Meema, K.M. (Eds.). John Wiley & Sons Ltd. New York, pp. 119–146.

Peech, M., 1965. Hydrogen-Ion Activity. In: Methods of soil analysis. Part 2. Chemical and microbiological properties. Black, C.A., Evans, D.D., White, J.L., Ensminger, L.E., Clark F.E. (Eds.), Soil Science Society of America. Madison, Wisconsin, USA. pp. 914-926.

Pepper, I.L., Gerba, C.P., Brendecke, J.W., 1995. Environmental microbiology: a laboratory manual. Academic Press Inc. New York, USA.

Peters, D.B., 1965. Water Availability. In: Methods of Soil Analysis: Part 1 Physical and Mineralogical Properties, Including Statistics of Measurement and Sampling. Black, C.A., Evans, D.D., White, J.L., Ensminger, L.E., Clark F.E. (Eds.), Soil Science Society of America. Madison, Wisconsin, USA. pp. 279-285.

Rowell, D.L., 1996. Soil Science: methods and applications. Longman, UK. 350p.

Tan, X., Kong, L., Yan, H., Wang, Z., He, W., Wei, G., 2014. Influence of soil factors on the soil enzyme inhibition by Cd. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 64(8): 666-674.

US Salinity Laboratory Staff, 1954. Diagnosis and improvement of saline and alkali soils. US Department of Agriculture Handbook 60, Washington, DC.

Vig, K., Megharaj, M., Sethunathan, N., Naidu, R., 2003. Bioavailability and toxicity of cadmium to microorganisms and their activities in soil: a review. Advances in Environmental Research 8(1): 121–135.

Walkley, A., Black, C.A., 1934. An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil Science 37(1): 29–38.

Yeboah, J.O., Shi, G., Shi, W., 2021. Effect of heavy metal contamination on soil enzymes activities. Journal of Geoscience and Environment Protection 9: 135-154.

Zhang, R., Zhang, H., Yang, C., Li, H., Wu, J., 2024. Effects of water stress on nutrients and enzyme activity in rhizosphere soils of greenhouse grape. Frontiers in Microbiology 15:1376849.