2008 Joint Annual Meeting (5-9 Oct. 2008): Tillage and Crop Rotation Impact on Soil Microbial Activity.
Start | Author Index

744-9 Tillage and Crop Rotation Impact on Soil Microbial Activity.



Wednesday, 8 October 2008: 10:30 AM
George R. Brown Convention Center, 370C
Irfan Aziz, Dept. of Agronomy, University of Arid Agriculture, Rawalpindi, Pakistan, T. Mahmood, Dept. of Environmental Sciences, University of Arid Agriculture, Rawalpindi, Pakistan, Y. Raut, The Ohio State University South Centers, 1864 Shyville Road, Piketon, OH 45661 and Khandakar Islam, Ohio State University - OARDC, OSU South Centers, 1864 Shyville Rd, Piketon, OH 45661-9749
Soil microbial biomass and their activity are sensitive indicators of C sequestration. A randomized block design in 2 (tillage system) x 3 (crop rotation) factorial arrangement was laid-out to evaluate the impact (1990 to 2007)of tillage and crop rotation on soil microbial activity. Tillage treatments included conventional (CT) vs. and no-till (NT) were factored into continuous corn (CC), corn-soybean (CS), and corn–soybean-wheat-cowpeas (CSW) rotation. Composite soil samples were collected at 0-7.5, 7.5-15, 15-22.5 and 22.5-30 cm, 2-mm sieved, and analyzed for total microbial biomass (Cmic), basal (BR) and specific respiration rates (qCO2), potentially mineralizable C (Cmin), total C (Corg), pH, electrical conductivity, and bulk density (rb). Tillage significantly impacted Cmic, BR and qCO2 with an interaction from soil depth and crop rotation. NT had more than 56% Cmic, 9% Cmic:Corg, and 29% CMin compared to CT. More C (29%) mineralized under CT compared to NT. Likewise, Cmic, Cmic:Corg, BR, and qCO2 were significantly influenced by crop rotation. The CSW had more than 25% Cmic and 3% BR associated with lower qCO2 compared with CC and CS. The Cmic and BR rates have shown similar or a slightly different pattern when expressed on a mass per unit area basis at different depths or within soil profile calculated by taking the differences of rb into account. Overall, NT with CSW had greater microbial activity over CT or CC and CS.
See more of: Soil Carbon Dynamics
See more of: S03 Soil Biology & Biochemistry