Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/4/2010
Publication Date: 10/31/2010
Citation: Banks, M.L., Eivazi, F., Kremer, R.J., Motavalli, P.P., Nelson, K.A. 2010. Effects of Selected Surfactants on Nutrient Uptake and Soil Microbial Activity [abstract]. American Society of Agronomy. 2010 CDROM. Interpretive Summary:
Technical Abstract: Surfactants are adjuvants that facilitate and accentuate the emulsifying, dispersing, spreading, wetting, or other surface modifying properties of liquids. Many pesticides require the addition of a surfactant to improve pesticide performance in spray solution. Soils are one of the direct recipients of surfactants and little is known about the behavior and fate of these chemicals on the soil ecosystem. Surfactants may compete with nutrients, pesticides, or heavy metals for adsorption sites in soil. Additionally, surfactants may have an impact on soil microbial activity. The objective of this study was to determine the effects of surfactants on nutrient uptake and microbial activities. The following categories of surfactants with trade names of Activator, Agridex, and Thrust were used. These surfactants were coupled with herbicides glyphosate, atrazine, and bentazon respectively. Treatments added were surfactant only, herbicide only, and surfactant with herbicide. A greenhouse experiment was conducted using two different types of soils; silt clay and silty clay loam. Air dried soils of 4000 g were weighed into each pot (20-cm diameter). Each pot was fertilized according to soil test recommendations. Pots were arranged in a randomized complete block design. Field corn (Zea mays L.) was used as the test crop and allowed to grow for eight weeks. Above ground portions of corn were harvested, dried and ground. Ground plant tissues were digested using microwave digestion and analyzed with ICP to determine different nutrient concentrations. Microbial characterization of soil samples included microbial biomass carbon (MBC) and gas chromatograph fatty acid methyl ester (GCFAME) analyses to characterize the microbial community. The denaturing gradient gel electrophoresis (DGGE) technique was used to determine changes in the genetic community structure affected by the different treatments.