Publication Date:
2008-08-01
Description:
Clam canning in New Brunswick generates 1800 t of clam processing wastes (CPW) annually. Thirty-year-old stockpiles of CPW must now be remediated to satisfy environmental regulations. This study examined fresh and aged CPW as potential agricultural liming materials for acidic coastal vegetable production soils. Clam processing wastes were ground to three size fractions (〈 0.250 mm, 0.250 to 〈 1.00 mm, 1.00 to 〈 2.00 mm) and analyzed for calcium carbonate equivalent (CCE). They were then mixed with two soils of contrasting textures at three rates, in duplicate, and then placed in a control-plus-factorial pot experiment, with commercial agricultural lime of fine texture (〈 0.250 mm) as reference. During an 8-wk incubation, soil water pH and electrical conductivity (EC) were monitored biweekly. At 4 and 8 wk, a soil extract germination test was conducted using cress (Lepidium sativum L.) as an indicator plant. CPW of 〈 1 mm raised soil pH with effectiveness increasing as particle size decreased. Application rates in function of the fineness to induce a given pH change (ΔpH) could be obtained using prediction graphs with high coefficients of determination (r2: 0.84 to 0.97). The average EC in all treatments to the end of the incubation period was 〈 2 dS m-1, indicating that salt stress is not a risk following CPW application to soil, since even sensitive crops are capable of withstanding such an EC. Seeding could take place between 4 and 8 wk after the CPW application to loamy sand with no adverse effect on germination index. In the loam soil, this period could safely be shortened. Key words: Clam, liming, soil pH, soil EC, cress, germination index
Print ISSN:
0008-4271
Electronic ISSN:
1918-1841
Topics:
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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