ARS | Publication request: The role of biosolids in replenshing organic matter in cultivated soil

Submitted to: Soil Ecology Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 24, 2011
Publication Date: May 24, 2011
Citation: Guanglong, T., Cox, A., Granato, T., Chiu, C., Franzluebbers, A.J. 2011. The role of biosolids in replenshing organic matter in cultivated soil [abstract]. Soil Ecology Meeting Abstracts. Publication page.

Technical Abstract: The capacity of soil in sustaining crop production and providing ecosystem service is largely dependent on the soil organic matter (SOM). The replenishment of SOM in cultivated agricultural soils is very slow because of low input of recalcitrant litter and high rates of SOM oxidation. In this paper, we evaluated data from recent studies on biosolids C sequestration and other published work on biosolids and soil C dynamics to address the hypothesis that biosolids can effectively build-up the organic matter in the cultivated soils. Data from a long-term experiment established in western Illinois on overburden from surface mining with continuous corn cropping showed that the build-up of soil organic C (SOC) from 1973-2010 was only 0.40 Mg ha-1 yr-1 under chemical fertilizer. However, with the application of biosolids of 17 Mg ha-1 yr-1, the SOC build-up was 1.1 Mg ha-1 yr-1. Carbon-13 isotope analysis showed the residual biosolids C and crop residue C both account for the greater SOC build-up under biosolids application. The SOM in biosolids-amended soils is mainly in particulate form with a high stability as demonstrated by the low microbial quotient (C mineralization by each unit of microbial biomass). The humic acids extracted from biosolids-amended soils had a high alkyl to O-alkyl C ratio, indicating high humification. The faster build-up in SOM under biosolids application is attributed to the amorphous Fe and Al in biosolids, which forms associations with SOM and increase SOM stability.