CKD Application for Soil Improvement and Greenhouse Gas Mitigation

Cement kiln dust (CKD), a highly alkaline byproduct of cement manufacturing (Elbaz et al., 2019), is produced in large quantities and is commonly disposed of in landfills despite its potential value as a soil amendment. CKD may improve soil pH, nutrient availability, and soil functioning, and it may also help reduce greenhouse gas (GHG) emissions from agricultural soils. Although CKD contains trace levels of heavy metals, including V, Cr, As, Cd, and Pb, findings from our completed incubation study, together with assessments conducted by Norstar, indicate that these constituents are not present at levels of environmental concern with CKD application (Barnat-Hunek et al., 2018). Norstar has received Canadian Food Inspection Agency approval for CKD’s land application. However, field-based evidence remains limited regarding the effects of high-rate CKD application (6 t ha?¹), particularly when combined with reduced fertilizer inputs and complementary amendments such as digestate and humic substances. This project will address that gap through a field study at the Breton Plots, University of Alberta. Five treatments will be compared: (1) conventional chemical fertilizer management; (2) high CKD with the full fertilizer rate; (3) high CKD with 50% fertilizer; (4) high CKD plus digestate with 50% fertilizer; and (5) high CKD plus a humic product (H3) with 50% fertilizer. The study will evaluate effects on soil properties and GHG emissions (CO2, N2O, and CH4). Norstar Industries Ltd. is a socially and environmentally conscious Canadian company operating in the agriculture, environmental, and construction sectors. Its agriculture division develops sustainable products to improve nutrient use efficiency and address soil constraints. The project will generate scientific evidence on whether CKD-based amendment strategies can improve soil quality, reduce fertilizer dependence, lower agricultural GHG emissions, and support the beneficial reuse of industrial byproducts, with potential benefits for sustainable nutrient management, climate change mitigation, and circular economy goals. The project aligns with the efforts of the Canadian Net-Zero Energy Solutions (CANZES) to reduce GHG emissions on land and diversify Alberta’s economy.

Faculty Supervisor:

Scott Chang

Student:

Partner:

Norstar

Discipline:

Earth science

Sector:

Agriculture; Wholesale trade

University:

University of Alberta

Program: