Management effects on the dynamics and storage rates of organic matter in long-term crop rotations
Abstract
Factors controlling soil organic matter (SOM) dynamics in soil C sequestration and N fertility were determined from multi-site analysis of long-term, crop rotation experiments in Western Canada. Analyses included bulk density, organic and inorganic C and N, particulate organic C (POM-C) and N (POM -N), and CO2-C evolved during laboratory incubation. The POM-C and POM-N contents varied with soil type. Differences in POM-C contents between treatments at a site (δPOM-C) were related (r2= 0.68) to treatment differences in soil C (δSOC). The CO2-C, evolved during laboratory incubation, was the most sensitive indicator of management effects. The Gray Luvisol (Breton, AB) cultivated plots had a fivefold difference in CO2-C release relative to a twofold difference in soil organic carbon (SOC). Soils from cropped, Black Chernozems (Melfort and Indian Head, SK) and Dark Brown Chernozems (Lethbridge, AB) released 50 to 60% as much CO2-C as grassland soils. Differences in CO2 evolution from the treatment with the lowest SOM on a site and that of other treatments (δCO2-C) in the early stages of the incubation were correlated to δPOM-C and this pool reflects short-term SOC storage. Management for soil fertility, such as N release, may differ from management for C sequestration.
Department
Soil Biogeochemistry and Microbial Ecology
Publication Date
2-1-2004
Journal Title
Canadian Journal of Soil Science
Publisher
Canadian Science Publishing
Digital Object Identifier (DOI)
Document Type
Article
Recommended Citation
E. A. Paul, H. P. Collins, K. Paustian, E. T. Elliott, S. Frey, N. Juma, H. Janzen, C. A. Campbell, R. P. Zentner, G. P. Lafond, and A. P. Moulin. 2004. Management effects on the dynamics and storage rates of organic matter in long-term crop rotations. Canadian Journal of Soil Science. 84(1): 49-61. https://doi.org/10.4141/S03-022