|TIAN, GUANGLONG - Metropolitan Water Reclamation District Of Greater Chicago (MWRD)|
|CHIU, CHI-YU - Biodiversity Research Center, Academia Sinica (BRCAS)|
|OLAWALE, OLADEJI - Metropolitan Water Reclamation District Of Greater Chicago (MWRD)|
|GRANATO, THOMAS - Metropolitan Water Reclamation District Of Greater Chicago (MWRD)|
|COX, ALBERT - Metropolitan Water Reclamation District Of Greater Chicago (MWRD)|
Submitted to: Applied Soil Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2014
Publication Date: 10/2/2014
Citation: Tian, G., Chiu, C., Franzluebbers, A.J., Olawale, O.O., Granato, T.C., Cox, A.E. 2014. Biosolids amendment dramatically increases sequestration of crop residue-carbon in agricultural soils in western Illinois. Applied Soil Ecology. 85:86-93.
Interpretive Summary: Greenhouse gas emissions are increasing in the atmosphere and pose a threat to stable climate. Sequestration of carbon in soil is a key strategy to improve fertility for agricultural production and to mitigate emissions of greenhouse gases. A team of researchers from the Metropolitan Water Reclamation District of Greater Chicago, Academic Sinica in Taiwan, and USDA-ARS in Raleigh North Carolina collaborated to study the effect of long-term application of municipal biosolids to agricultural fields near Chicago as a mechanism to improve the capability of soil to sequester carbon from crop residue decomposition. Municipal biosolids were indeed effective at enhancing the retention of carbon from crop residues into soil organic matter and avoiding loss of carbon dioxide to the atmosphere. These results suggest that municipal biosolids that are low in heavy metals and other harmful contaminants can be an effective means to enhance soil carbon sequestration and improve long-term fertility of agricultural soils throughout the Midwest US, as well as possibly other agricultural areas near major cities around the country.
Technical Abstract: Release of carbon dioxide through microbial respiration from the world’s crop residues (non-edible plant parts left in the field after harvest) represents an important form of carbon transfer from terrestrial ecosystems to the atmosphere. We hypothesized that alleviation of environmental stress (moisture stress and substrate carbon and nitrogen imbalance) to microorganisms by a soil amendment can increase the sequestration of crop residue-C in agricultural soils. Municipal biosolids (treated sewage sludge with high stable organic matter and low C:N ratio) were applied at mean annual rate of 42 Mg/ha (dry weight) to eight agricultural fields (biosolids-amended) for 13 years (1972-1984) in western Illinois. Four agricultural fields (unamended) received chemical fertilizer as control. We measured the sequestration rate of crop residue-C in soil over the span of 34 years (1972-2006) using the 13C technique. The percentage of crop residue-C input sequestered in soil was 11.8 ± 1.6% in unamended soil and 32.5 ± 1.7% in biosolids-amended soil. Biosolids amendment reduced soil microbial stress as evidenced by the low microbial metabolic quotient. With microbial stress alleviation using biosolids, temperate agricultural soils could potentially sequester 0.57-0.76 Pg C per year, offsetting annual global CO2 emissions by 6.2-8.2% at 95% confidence level. We conclude that for agricultural soils to effectively sequester C, soil microbial stress needs to be alleviated through restoration of soil organic matter by amendment, particularly with biosolids having high stable C and low C:N ratio.