Figure 5. Schematic of physical and chemical analysis of dredged material useful in determining barriers to plant establishment (Lee et al. 1985)

Technical Note DOER-C3

May 1999

Figure 5. Schematic of physical and chemical analysis of dredged material useful in determining barriers

to plant establishment (Lee et al. 1985)

phytoreclamation to work successfully, amendments or pretreatments may be necessary to

manipulate the physical and/or chemical characteristics of some dredged materials for

optimum results. These manufactured soil screening tests will ensure that plant establishment

and adequate growth are attainable. Some dredged materials may contain excessive levels

of salt or certain contaminants that inhibit seed germination by restricting water transfer from

the material to the seed, resulting in poor germination. Seed germination is evaluated for

each plant species on each dredged material in question. Excessive levels of many contami-

nants may inhibit plant growth either by toxic uptake or by interfering with life-sustaining

functions.

For plant growth comparisons, plants are grown in the dredged material or manufactured soil blends

in 10-cm nursery containers for 49 days, and the aboveground plant material is harvested and total

dry weight biomass is determined. The blend that produces the highest biomass yield is selected

for recommendation. These tests will provide an assessment of the growth potential of various

plants and amendment combinations.

TESTS FOR EVALUATING PHYTORECLAMATION EFFECTIVENESS: Contaminated

dredged material is unique for each dredging location in physical and chemical characteristics.