Pedosphere 23(4): 409--416, 2013
ISSN 1002-0160/CN 32-1315/P
©2013 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Soil organic carbon pools under switchgrass grown as a bioenergy crop compared to other conventional crops |
F. G. DOU1 , F. M. HONS2, W. R. OCUMPAUGH3, J. C. READ4, M. A. HUSSEY2 and J. P. MUIR5 |
1Texas A&M AgriLife Research & Extension Center at Beaumont, 1509 Aggie Drive, Beaumont, TX 77713 (USA)
2Department of Soil and Crop Sciences, Texas A&M University, 2474 TAMU, College Station, TX77843-2474 (USA)
3Texas A&M AgriLife Research Station at Beeville, HCR-2, Box 43-C, Beeville, TX 78102-9410 (USA)
4
Texas A&M AgriLife Research and Extension Center at Dallas, 17360 Coit Road, Dallas, TX 75252-6599 (USA)
5
Texas A&M AgriLife Research and Extension Center at Stephenville, Route 2, Box 00, Stephenville, TX, 76401 (USA) |
| ABSTRACT |
| Switchgrass (Panicum virgatum L.) has been proposed as a sustainable bioenergy crop because of its high yield potential, adaptation to marginal sites, and tolerance to water and nutrient limitations. A better understanding of the potential effects of biomass energy crop production practices on soil biological properties and organic matter dynamics is critical to its production. Our objective was to evaluate changes in C pools under a warm-season perennial switchgrass in different soils compared to typically-grown crops collected at College Station, Dallas, and Stephenville, TX in February 2001. Sampling depths were 0--5, 5--15, and 15--30 cm. Switchgrass increased soil organic C (SOC), soil microbial biomass C (SMBC), mineralizable C, and particulate organic matter C (POM-C) compared to conventional cropping systems. Soil C concentrations were in the order: long-term coastal bermudagrass [Cynodon dactylon (L.) Pers.] > switchgrass or kleingrass (Panicum coloratum L.) planted in 1992 > switchgrass 1997 > conventional cropping systems. Soil C concentrations tended to increase with increasing clay content. Greater microbial biomass C followed the order of Dallas > College Station > Stephenville, and ranged from approximately 180 mg C kg-1 soil at Stephenville to 1 900 mg C kg-1 soil at Dallas. Particulate organic C was more sensitive than other fractions to management, increasing as much as 6-fold under long-term coastal bermudagrass compared to conventional cropping systems. Our study indicated that conversion of conventional cropping systems into switchgrass production can sequestrate more SOC and improve soil biological properties in the southern USA. |
| Key Words: cropping systems, particulate organic C, perennial grasses, soil microbial biomass C, soil mineralizable C |
| Citation: Dou, F. G., Hons, F. M., Ocumpaugh, W. R., Read, J. C., Hussey, M. A. and Muir, J. P. 2013. Soil organic carbon pools under switchgrass grown as a bioenergy crop compared to other conventional crops. Pedosphere. 23(4): 409-416. |
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