Pedosphere 24(3): 408--416, 2014
ISSN 1002-0160/CN 32-1315/P
©2014 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Soil carbon, nitrogen and microbial dynamics of pasturelands: Impacts of grazing intensity and planting systems |
WANG Yi1,2, DUAN Wen-Xia2,3, C. TU2 , S. WASHBURN4, CHENG Lei2 and S. HU2 |
1State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075 (China)
2Department of Plant Pathology, North Carolina State University, Raleigh NC27695-7616 (USA)
3Sichuan Tourism University, Chengdu 610100(China)
4Department of Animal Science, North Carolina State University, Raleigh NC27695-7621 (USA) |
| ABSTRACT |
| Management intensity critically influences the productivity and sustainability of pasture systems through modifying soil microbes, and soil carbon (C) and nutrient dynamics;however, such effects are not well understood yet in the southeastern USA. We examined the effects of grazing intensity and grass planting system on soil C and nitrogen (N)dynamics, and microbial biomass and respiration in a long-term field experiment in Goldsboro, North Carolina, USA. A split-plot experiment was initiated in 2003 on a highly sandy soil under treatments of two grass planting systems (ryegrass rotation with sorghum-sudangrass hybrid and ryegrass seeding into a perennial bermudagrass stand) at low and high grazing densities. After 4 years of continuous treatments, soil total C and N contents across the 0--30 cm soil profile were 24.7% and 17.5% higher atthe highthan at the low grazing intensity, likely through promoting plant productivity and C allocation belowground as well as fecal and urinary inputs. Grass planting system effects were significant only atthe low grazing intensity, with soil C, N, and microbial biomass and respiration in the top 10 cm being higher under the ryegrass /bermudagrass than under the ryegrass/sorghum-sudangrass hybridplanting systems. These results suggest that effective management could mitigate potential adverse effects of high grazing intensities on soil properties and facilitate sustainability of pastureland. |
| Key Words: C allocation,grass species, microbial respiration microbial biomass, pastureland sustainability, plant productivity |
| Citation: Wang, Y., Duan, W. X., Tu, C., Washburn, S., Cheng, L. and Hu, S. 2014. Soil carbon, nitrogen and microbial dynamics of pasturelands: Impacts of grazing intensity and planting systems. Pedosphere. 24(3): 408-416. |
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