ARS | Publication request: CARBON AND NITROGEN MINERALIZATION OF SOIL UNDER LONG-TERM TILLAGE AND MANURE APPLICATION

Submitted to: Soil Science Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: November 7, 2005
Publication Date: November 7, 2005
Citation: Watts, D.B., Torbert III, H.A., Prior, S.A. 2005. Carbon and nitrogen mineralization of soil under long-term tillage and manure application [abstract]. American Society of Agronomy. 2005 CDROM

Technical Abstract: More information is needed on the rate of C and N that is being mineralized and sequestered in soil subjected to long-term manure application under different tillage practices. Thus, a laboratory incubation study was conducted under aerobic conditions to evaluate the residual effect of manure from long-term application ( >10 years) as affected by tillage. Soil sample were collected at three depths (0-5, 5-10, and 10-20 cm) from plots with and without manure under conventional and no-tillage systems at the Sand Mountion Substation in the Appalachian Plateau region of Northeast Alabama on a Hartsell fine sand loam. Carbon mineralization was measured by capturing CO2 in alkali traps (NaOH) and titrating with HCL. Nitrogen mineralization was measured by calculating nitrate and ammonium change over time using 2M KCL soil extractions. The amount of C mineralized was significantly higher at 0-5 cm depth for no-tillage and conventional tillage compared to the other depths. A similar pattern was also observed with N mineralization rates. Plots subjected to long-term manure application had a higher C and N mineralization rate compared to plots without manure. The deeper depths showed higher C and N mineralization occurring in the conventional tillage plots compared to that of no-tillage plots. This is probably due to mixing of soil in the plow layer. The information acquired from this study may aid in better understanding the effects that tillage has on the long-term storage of C and N with manure applications.