Soil Organic Carbon and Nitrogen Storage in
Aggregate Fractions of Monoculture Cropping Sequences in Texas. (3508)
Authors:
A.L. Wright* - Texas A&M University F.M. Hons - Texas A&M University
Abstract:
No tillage (NT) has the potential to enhance C and N sequestration in agricultural soils of the southern USA. The objectives of this study were to investigate the impacts of tillage and crop species on soil organic C (SOC) and N (SON)
sequestration and distribution within aggregate-size fractions in a central Texas soil after 20 years of management. No tillage increased SOC storage at 0 to 5 cm by 97, 47, and 72%, and SON storage by 117, 56, and 44%, for continuous grain sorghum [Sorghum bicolor (L.) Moench], wheat (Triticum aestivum L.), and soybean
[Glycine max (L.) Merr.], respectively. Crop species had significant impacts on SOC and SON sequestration. On average, the wheat monoculture had greater SOC storage (9225 kg C ha-1) at 0 to 5 cm than sorghum (6750 kg C ha-1) and soybean (7050 kg C ha-1). No-tillage increased the proportion of >2-mm and 250 um to 2-mm macroaggregate-size fractions in soil compared to conventional tillage (CT).
At 0 to 5 cm, NT increased SOC storage by 158% in macroaggregate fractions.
Speaker Information: Alan Wright, Texas A&M University, Texas A&M University Soil & Crop Sciences Dept. 2474 TAMU, College Station, TX 77843; Phone:
979-845-3814; E-mail: [email protected]
Session Information: Monday, November 1, 2004, 1:00 PM-3:00 PM Presentation Start: 1:00 PM (Poster Board Number: 2723)
