SUMMARY - doerc60007

Technical Note DOER-C6

May 1999

Malformation or distortion of the younger leaves is also a characteristic feature of calcium-deficient

plants, a hooking of the leaf tip being the most easily detected symptom. Magnesium deficiency in

green plants is extensive interveinal chlorosis of the leaves. Excessive salt in dredged material

and/or blend will inhibit plant growth by decreasing water availability to the roots and inhibiting

physiological processes that require water (Lee et al. 1985). Excessive salt may cause leaf epinasty

(downward curving of the leaf blade), chlorosis, and death.

A case study involving dredged material from Toledo Harbor CDF Cell 1 will be presented to

illustrate how visual observations may be applied during a manufactured soil screening. Visual

observations, during the first 2 weeks, of leaf color, size, and shape revealed similarities between

plants growing in Blend 4 and plants growing in Blend 5 (fertile reference control). However, at

Day 21, plant growth in Blend 4 seemed slower than plant growth in Blend 5. Leaf color gradually

changed from green to yellow, and the leaves were not as broad as the plants growing in the fertile

reference control (Figures 1, 2, and 3). Yellow color and narrow leaves were ascribed to nutrient

deficiency in the manufactured soil blend. On Day 22, soluble ammonium-nitrate and Miracle

(13N-13P-13K) were added to all of the Toledo Harbor dredged-material blends. The

Gro

addition of nutrients to the blends appeared to have enhanced plant growth. At the end of 7 weeks,

visual observations of leaf color, size, and shape revealed similarities between plant species growing

in Blend 4 and plant species growing in Blend 5 (Figures 1, 2, and 3).

Ryegrass, tomato, and marigold grew better in Blend 4 than plants in Blends 1, 2, or 3 (Figure 3).

The total aboveground dry weight biomass obtained from Blend 4 was significantly higher than the

total aboveground biomass from Blend 5 (fertile reference control).

The results from the screening tests indicated that Blend 4, consisting of Toledo Harbor dredged

material, cellulose, and biosolids, will enhance plant growth. It was concluded that a high-quality

manufactured soil product could be blended using Toledo Harbor dredged material. Soil fertility

analysis and physical characterization of the blend was conducted. Commercialization of this

manufactured soil process has been initiated. A field demonstration was successfully conducted to

produce 550 cu yd of fertile topsoil. This manufactured topsoil was used to landscape the entrance

to the University of Toledo and improve soil beds at the entrance of the Toledo Botanical Gardens

(Figures 4 and 5).

SUMMARY: Since manufactured soil is new, innovative, and in its infancy stage, caution should

be used in applying this technology. The technology affords a practical means of promoting the

reuse of uncontaminated and even contaminated dredged material and the Nation's organic waste

material. The evaluation of the feasibility of manufacturing a productive soil product from dredged

material should include a two-phase approach. Phase 1 should include the bench-scale screening

evaluations for seed germination and plant growth and the physical and chemical characterization

of the dredged material and blend. If the screening tests show that the dredged material can

potentially be used to manufacture a fertile soil product, then a second phase, either a demonstration

project using the blend identified in the bench-scale tests could be conducted or commercialization

of the process could be initiated.

The manufactured soil technology is site specific. The optimal blend for a specific dredged material

will depend on the physical and chemical characteristics of that dredged material and the available