Portsmouth soil

Since the actual or potential phytotoxicity of a phenolic acid is determined by its physical and chemical properties and the susceptibility of the plant process involved, the actual or potential phytotoxicity of a given phenolic acid is best determined in nutrient culture in the absence of soil processes. The phytotoxicity observed in soil systems represents a realized or observed phytotoxicity, not the actual phytotoxicity, of a given phenolic acid. For example, the actual relative phytotoxicities (or potencies) for cucumber seedling leaf expansion were 1 for ferulic acid, 0.86 for p-coumaric acid, 0.74 for vanillic acid, 0.68 for sinapic acid, 0.67 for syringic acid, 0.65 for caffeic acid, 0.5 for p-hydroxybenzoic acid and 0.35 for protocatechuic acid in a pH 5.8 nutrient culture.5 In Portsmouth Bt-horizon soil (Typic Umbraquaalts, fine loamy, mixed, thermic pH 5.2), they were 1, 0.67, 0.67, 0.7, 0.59, 0.38, 0.35, and 0.13, respectively.19 The differences in phytotoxicity of the individual phenolic acids for nutrient culture and Portsmouth soil bioassays were due to various soil processes listed in the next paragraph and reduced contact (e.g., distribution and movement)36 of phenolic acids with roots in soils. 

Detectable changes in microbial populations after phenolic acid enrichment of Portsmouth soil took only days.7 Bacterial populations in soil treated with multiple treatments of 0.5 pmol/g ferulic acid reached maximum population levels in 5 and 3 days in the A- and B- horizon soils, respectively, and then declined. Bacterial populations in soil not treated with phenolic acids increased somewhat over the first 24 to 72 h and thereafter remained fairly constant. Fungal populations... 

In 1993, Geo-Con, Inc., first used the shallow soil mixing/thermaUy enhanced vapor extraction (SSM/TEVE) technology at the Portsmouth Gaseous Diffusion Plant. It has since been used at several other sites to accelerate contaminant volatilization (D14483M, p. 2). 

At the U.S. Department of Energy s (DOE s) Portsmouth Gaseous Diffusion Plant in Ohio, treatment of 20,000 yd of soil cost approximately 3.5 million (D10096Z, p. 10). 

Gerig, T. M. and Blum, U. 1991. Effects of mixtures of four phenolic acids on leaf area expansion of cucumber seedlings grown in Portsmouth B- soil materials. J Chem. Ecol. 17, 29-40... 

Table 2.1 Soil characteristics of Cecil, Portsmouth, and White Store soils ...

Fig. 2.13 Recovery of femUc add by various extraction procedures from sterile soils 90 days after ferulic acid solutions (1,000 mg/kg sod, pH 6.0) were added to sods. Sod-ferulic acid mixtures were stored in the dark at room temperature. LSDq os for Cecd A and B and Portsmouth A and B soils were 28.70, 44.15, 40.69, and 28.66, respectively. Meaning of the abbreviations and details for extraction procedures are provided in Table 2.3. Figure based on data from Dalton et al. (1987). Data used with permission of Sod Science Society of America...

Dalton et al. (1989b) utilizing Mehlich 111, a mild chelating extractant, also observed that the recovery of available phenolic acids (femlic acid, vanillic acid, p-coumaric acid, p-hydroxybenzoic acid) from sterile soil (Cecil, Portsmouth and White Store) varied with soil type, horizon, time, and the type of phenolic acid added. When they allowed phenolic acids added to soil to equilibrate for 2 min before extraction, they noted a significant reduction in recovery of phenolic acids. Recovery declined with time up to 32 days. The decline was most rapid over the first 2 days. The presence of methoxy groups and acrylic side chains increased... 

Fig. 2.19 Response of bacteria (a), fast-growing bacteria (b), and fungi (c) in Portsmouth A and B soils to 0 and 0.5 p.mol/g soil ferulic acid appUed every other day steirting with day 1, where fast-growing bacteria represent colonies that were > 1 mm in diameter after 6 days of incubation. For (a) LSDq.05 = 2.9 x 10, for (b) LSDq.os = 2.88 x 10, and for (c) LSDo.os = 2.4 x 10. Figures reproduced from Blum and Shafer (1988)...

Fig. 2.21 Concentrations for one to a mixture of four phenolic acids required for a 30% inhibition of mean absolute rates of leaf expansion for 8-18 day old cucumber seediings growing in Portsmouth B soil. Figure reproduced from Blum (1996). Figure used with permission of Society of Nematologists...

Fig. 2.22 Concentrations of p-coumaric acid and metMonine (a), and p-coumaric acid and glucose (b) required to inhibit dry weight of morningglory seedlings growing in Portsmouth B and Cecil B soils, respectively, by 10-50%. Figures adapted/repUcated from Blum et al. (1993) (a) and Pue et al. (1995) (b). Plenum Publishing Corporation, figuresused with permission of Springer Science and Business Media...

Response of bacteria (a), fast-growing bacteria (b), and fungi (c) in Portsmouth A and B soils to 0 and 0.5 p,mol/g soil femlic acid applied every other day starting with day 1, where fast-growing bacteria represent colonies that were >... 

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