Phenolic Acids in Cecil Soils

3 Plant-Plant Allelopathic Interaction. Phase II Field/Laboratory Experiments 

Highest average phenolic acid concentration recovered from Cecil A soil samples was 4 p.g/g soil for p-coumaric acid, a cinnamic acid. In general benzoic acids (vanillic, p-hydroxybenzoic acid, and sinapic acid) were higher in concentration than cinnamic acids (caffeic acid, ferulic acid, and syringic acid), with the exception of p-coumaric acid. 

Individual, the sum of 7 common phenolic acids, and total phenolic acid content in soil extracts from Cecil A soil were found to be correlated with each other and with moisture, pH, carbon, and nitrogen of the soil. 

Total phenolic acid content of wheat no-till, wheat conventional-till, and fallow conventional-till soil samples was approximately 15 times higher than the sum of caffeic acid, p-coumaric acid, ferulic acid, /i-hydroxybenzoic acid, sinapic acid, syringic acid, and vanillic acid. Concentrations for the sum of the 7 phenolic acids were 34% greater in 0-2.5 cm soil samples than in 0-10 cm soil samples. 

Concentrations of individual, sum of 7 phenolic acids, and total phenolic acid content in Cecil soil appeared to be fairly constant over the experimental periods studied. For example, the maximum changes for the sum of 7 phenolic acids over the experimental periods were on the order of 20-30%. 

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Blum, U., Worsham, A. D., King, L. D. and Gerig, T. M., 1994. Use of water and EDTA extractions to estimate available (free and reversibly bound) phenolic acids in Cecil soils. J. Chem. Ecol. 20, 341-359... 

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