Best-Ordinioha et al
Greener Journal of Soil Science and Plant Nutrition Vol. 3 (1), pp. 025-031, October 2016.
© 2015 Greener Journals
The Effect of the Application of Different Rates of Herbicides on Soil Microorganisms
1*Mrs. Joyce Chinyere Best-Ordinioha, 2Prof. Anthony E. Ataga,
3Dr. Edache B. Ochekwu
1Doctoral Student, Department of Plant Science and Biotechnology, Faculty of Sciences, University of Port Harcourt, Port Harcourt, Rivers State.
2Professor, Department of Plant Science and Biotechnology, Faculty of Sciences, University of Port Harcourt, Port Harcourt, Rivers State.
3Senior Lecturer, Department of Plant Science and Biotechnology, Faculty of Sciences, University of Port Harcourt, Port Harcourt, Rivers State.
Background: The use of herbicide in weed control has grown significantly in Nigeria in recent years. Most of the application are indiscriminately carried out by illiterate farmers, and therefore pose a significant threat to the environment and on crop yield. This study assessed the effects of the use of glyphosate for land preparation, and different concentrations of primextra dual gold (atrazine and metolachlor), for weed control on the type and population of soil micro-organisms.
Methods: The study was carried out in Port Harcourt in two phases, using a randomized complete block design with three replicates. Soil samples were collected at the depths of 0-15cm and 15-30cm, and analyzed 4WAP and 12WAP. Serial dilution technique was used for the enumeration of the bacteria and fungi in the soil samples, using the spread plate method, and the appropriate media and incubation conditions.
Results: The use of the herbicides resulted in changes in the soil, and in the type and number of soil micro-organisms. There were reductions in the organic matter and exchangeable minerals content of the soil, and in the total count of the micro-organisms in the second phase of the study. The mean bacteria count in the first phase of the study were 5.75 x 108 CFU and 1.13 x 108 CFU at the depths of 0 – 15cm and 15 – 30cm respectively, compared to 2.88 x 104 CFU and 6.32 x 104 CFU in the second phase of the study. The reductions were more in the plots in which the herbicides had been applied above the recommended dose.
Conclusion: The application of the herbicides resulted in changes in the soil, and type and total number of soil micro-organisms, especially when they are applied at above the recommended rate. Efforts are therefore needed to educate farmers on the proper dosing of the herbicides.
Keywords: Herbicides, Glyphosate, atrazine, metolachlor, bacterial count, soil fungal count, Nigeria.
Agahiu AE, Baiyeri KP, Ogbuji RO, Udensi UE (2012). Assessment of status, perception of weed infestation and methods of weed control adopted by cassava farmers in Kogi state, Nigeria. Journal of Animal and Plant Sciences 13 (3): 1823 – 1830.
Agahiu AE, Udensi UE, Tarawali G, Okoye BC, Ogbuji RO, Baiyeri KP (2011). Assessment of weed management strategies and intercrop combinations on cassava yield in the middle belt of Nigeria. African Journal of Agricultural Research. 6 (26): 5729 – 5735.
Araújoa ASF, Monteiroa RTR, Abarkelib RB (2003). Effect of glyphosate on the microbial activity of two Brazilian soils. Chemosphere 52 (5): 799 – 804.
Ayansina AD, Oso BA (2008). Effect of organic amendments on microbial biomass of a tropical soil treated with some herbicides. Int. J. Biol. Chem. Sci. 2(4): 417 – 424.
Ayansina AD, Oso BA. (2006). Effect of two commonly used herbicide on soil microflora at two different concentrations. Afr. J. Biotech., 5(2): 129-132.
Bouchard DC, Lavy TL, Marx DB. (1982). Fate of metribuzin, metolachlor, and fluometuron in soil. Weed Sci. 30: 629 – 632.
Busse MD, Ratcliff AW, Shestak CJ, Powers RF (2001). Glyphosate toxicity and the effects of long-term vegetation control on soil microbial communities. Soil Biology and Biochemistry 33 (12–13): 1777 – 1789.
Cao P, Wang X, Liu F, Zhao E, Han L (2008). Dissipation and Residue of S-metolachlor in Maize and Soil. Bull Environ Contam Toxicol 80: 391 – 394.
Ding D, Novak JM, Herbert S, Xing B (2002). Long-term tillage effects on soil metolachlor sorption and desorption behavior. Chemosphere 48: 897 – 904.
Eme OI, Onyishi T, Uche OA. Uche IB (2014). Challenges of food security in Nigeria: options before government. Arabian Journal of Business and Management Review (OMAN Chapter). 4 (1): 15 – 25.
Franz JE, Sikorski JA, Mao MK (1997). Glyphosate: a unique global herbicide. American Chemical Society. Wasington, DC.
Gushit JS, Ekanem EO, Adamu HM, Abayeh OJ, Malan D (2013). Utilization pattern and risk assessment of herbicides usage by farmers, marketers and agricultural extension workers (AEWs) in Plateau State, Nigeria. International Journal of Agricultural Science Research 2(6): 177 – 184.
Hamid AA, Aiyelaagbe OO, Balogun GA (2011). Herbicides and its Applications. Advances in Natural and Applied Sciences, 5(2): 201 – 213.
Iyagba AG (2013). Assessing the safety use of herbicides by horticultural farmers in Rivers state, Nigeria. European Scientific Journal 9 (15): 97 – 108.
Ize-Iyamu, O.K., Asia, IO, Egwakhide PA (2007). Concentrations of residues from organochlorine pesticide in water and fish from some rivers in Edo State Nigeria. International Journal of Physical Sciences 2 (9): 237 – 241.
Krzysko-Lupicka, T., W. Strof, K. Kubs, M. Skorupa, P. Wieczorek and B. Lejczak. 1997. The ability of soil-borne fungi to degrade organophosphonate carbon-to-phosphorus bonds. Appl. Microbiol. Biotechnol. 48:549-552.
Liu, C., McClean P, Sookdeo C, Cannon F. (1991). Degradation of the herbicide glyphosate by members of the family rhizobiaceae. Appl. Environ. Microbiol. 57:1799-1804.
Liu, SY, Zheng Z, Zhang R, Bollag JM, (1989). Sorption and metabolism of metolachlor by a bacterial community. Appl. Environ. Microbiol., 55 (3): 733-740.
Munier Lamy C, Feuvrier MP, Chone T (2002). Degradation of 14CAtrazine Bound Residues in Brown soil and Rendzinz Fractions. J. Environ. Qual.31:241-247
Myers JP, Antoniou MN, Blumberg B, Carroll L, Colborn T, Everett LG, Hansen M, Landrigan PJ, Lanphear BP, Mesnage R, Vandenberg LN, vom Saal FS, Welshons WV, Benbrook CM (2016). Concerns over use of glyphosate-based herbicides and risks associated with exposures: a consensus statement. Environmental Health. 15:19.
Ojo EO, Adebayo PF (2012). Food security in Nigeria: An overview. European Journal of Sustainable Development 1(2): 199 – 222.
Partoazar M, Hoodaji M, Tahmourespour A (2011). The effect of glyphosate application on soil microbial activities in agricultural land. African Journal of Biotechnology 10 (83): 19419 – 19424.
Rueppel, M., B. Brightwell, J. Schaefer and J. Marvel. 1977. Metabolism and degradation of glyphosate in soil and water. J. Agric. Food Chem. 25:517-528.
Sprankle P, Meggitt W, Penner D (1975a). Adsorption, mobility, and microbial degradation of glyphosate in soil Weed Sci. 23: 229 – 234.
Tijani AA. Pesticides Use Practices and Safety Issues: The Case of Cocoa Farmers in Ondo State, Nigeria. J. Human Ecol., 2006; 19(3): 183-190.