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Improved grazing management may increase soil carbon sequestration in temperate steppe.

Chen W, Huang D, Liu N, Zhang Y, Badgery WB, Wang X, Shen Y - Sci Rep (2015)

Bottom Line: While deferred grazing (RHM and RMH) sequestered less soil carbon compared to MMM, they showed higher standing root mass, maintained a more desirable pasture composition, and had better ability to retain soil N.Constant high grazing pressure (HHH) caused diminished above- and belowground plant production, more soil N losses and an unfavorable microbial environment and had reduced carbon input.Overall, the soil carbon sequestration in the temperate grassland is affected by the grazing regime that is applied, and grazing can be altered to improve soil carbon sequestration in the temperate steppe.

View Article: PubMed Central - PubMed

Affiliation: Department of Grassland Science, College of Animal Science and Technology, China Agricultural University, West Road 2 Yuan Ming Yuan, Beijing 100193, P.R. China.

ABSTRACT
Different grazing strategies impact grassland plant production and may also regulate the soil carbon formation. For a site in semiarid temperate steppe, we studied the effect of combinations of rest, high and moderate grazing pressure over three stages of the growing season, on the process involved in soil carbon sequestration. Results show that constant moderate grazing (MMM) exhibited the highest root production and turnover accumulating the most soil carbon. While deferred grazing (RHM and RMH) sequestered less soil carbon compared to MMM, they showed higher standing root mass, maintained a more desirable pasture composition, and had better ability to retain soil N. Constant high grazing pressure (HHH) caused diminished above- and belowground plant production, more soil N losses and an unfavorable microbial environment and had reduced carbon input. Reducing grazing pressure in the last grazing stage (HHM) still had a negative impact on soil carbon. Regression analyses show that adjusting stocking rate to ~5SE/ha with ~40% vegetation utilization rate can get the most carbon accrual. Overall, the soil carbon sequestration in the temperate grassland is affected by the grazing regime that is applied, and grazing can be altered to improve soil carbon sequestration in the temperate steppe.

No MeSH data available.


Related in: MedlinePlus

Soil inorganic nitrogen contents (a) and net N mineralization rate (b) measured in mid-August 2013 in each regime, and the linear relationship between stocking rate with N mineralization rate (c). Bar groups with different lowercase letters indicate significant differences (P < 0.05) between regimes for (a,b) and data are means ± SE.
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f6: Soil inorganic nitrogen contents (a) and net N mineralization rate (b) measured in mid-August 2013 in each regime, and the linear relationship between stocking rate with N mineralization rate (c). Bar groups with different lowercase letters indicate significant differences (P < 0.05) between regimes for (a,b) and data are means ± SE.

Mentions: Similarly, grazing and soil depth effects (p < 0.05) were also detected for soil total nitrogen, and their interaction effects were significant (p < 0.05; Fig. 4b). The change in total soil nitrogen due to grazing was also observed in the top soil, but with a different pattern of change to soil organic carbon. Grazing regimes significantly affected the soil inorganic nitrogen contents and nitrogen mineralization in the top soil (F4,10 = 9.21, p < 0.05; F4,10 = 5.42, p < 0.05; Fig. 6a,b). Soil inorganic nitrogen contents showed no difference between HHH, HHM and MMM (Duncan’s multiple-range tests, p > 0.05), but were significantly higher than RHM and RMH (p < 0.05; Fig. 6a). The nitrogen mineralization rates measured during the grazing season were very low, even exhibiting immobilization under deferred grazing regimes. Conversely, the rates were significantly enhanced under HHH, HHM and MMM (p < 0.05; Fig. 6b). The net N mineralization showed a linear increase with increased stocking rate (Fig. 6c).


Improved grazing management may increase soil carbon sequestration in temperate steppe.

Chen W, Huang D, Liu N, Zhang Y, Badgery WB, Wang X, Shen Y - Sci Rep (2015)

Soil inorganic nitrogen contents (a) and net N mineralization rate (b) measured in mid-August 2013 in each regime, and the linear relationship between stocking rate with N mineralization rate (c). Bar groups with different lowercase letters indicate significant differences (P < 0.05) between regimes for (a,b) and data are means ± SE.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490272&req=5

f6: Soil inorganic nitrogen contents (a) and net N mineralization rate (b) measured in mid-August 2013 in each regime, and the linear relationship between stocking rate with N mineralization rate (c). Bar groups with different lowercase letters indicate significant differences (P < 0.05) between regimes for (a,b) and data are means ± SE.
Mentions: Similarly, grazing and soil depth effects (p < 0.05) were also detected for soil total nitrogen, and their interaction effects were significant (p < 0.05; Fig. 4b). The change in total soil nitrogen due to grazing was also observed in the top soil, but with a different pattern of change to soil organic carbon. Grazing regimes significantly affected the soil inorganic nitrogen contents and nitrogen mineralization in the top soil (F4,10 = 9.21, p < 0.05; F4,10 = 5.42, p < 0.05; Fig. 6a,b). Soil inorganic nitrogen contents showed no difference between HHH, HHM and MMM (Duncan’s multiple-range tests, p > 0.05), but were significantly higher than RHM and RMH (p < 0.05; Fig. 6a). The nitrogen mineralization rates measured during the grazing season were very low, even exhibiting immobilization under deferred grazing regimes. Conversely, the rates were significantly enhanced under HHH, HHM and MMM (p < 0.05; Fig. 6b). The net N mineralization showed a linear increase with increased stocking rate (Fig. 6c).

Bottom Line: While deferred grazing (RHM and RMH) sequestered less soil carbon compared to MMM, they showed higher standing root mass, maintained a more desirable pasture composition, and had better ability to retain soil N.Constant high grazing pressure (HHH) caused diminished above- and belowground plant production, more soil N losses and an unfavorable microbial environment and had reduced carbon input.Overall, the soil carbon sequestration in the temperate grassland is affected by the grazing regime that is applied, and grazing can be altered to improve soil carbon sequestration in the temperate steppe.

View Article: PubMed Central - PubMed

Affiliation: Department of Grassland Science, College of Animal Science and Technology, China Agricultural University, West Road 2 Yuan Ming Yuan, Beijing 100193, P.R. China.

ABSTRACT
Different grazing strategies impact grassland plant production and may also regulate the soil carbon formation. For a site in semiarid temperate steppe, we studied the effect of combinations of rest, high and moderate grazing pressure over three stages of the growing season, on the process involved in soil carbon sequestration. Results show that constant moderate grazing (MMM) exhibited the highest root production and turnover accumulating the most soil carbon. While deferred grazing (RHM and RMH) sequestered less soil carbon compared to MMM, they showed higher standing root mass, maintained a more desirable pasture composition, and had better ability to retain soil N. Constant high grazing pressure (HHH) caused diminished above- and belowground plant production, more soil N losses and an unfavorable microbial environment and had reduced carbon input. Reducing grazing pressure in the last grazing stage (HHM) still had a negative impact on soil carbon. Regression analyses show that adjusting stocking rate to ~5SE/ha with ~40% vegetation utilization rate can get the most carbon accrual. Overall, the soil carbon sequestration in the temperate grassland is affected by the grazing regime that is applied, and grazing can be altered to improve soil carbon sequestration in the temperate steppe.

No MeSH data available.


Related in: MedlinePlus