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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

The relationship between stocking rates and aboveground biomass production (a, solid symbols), belowground root production (b, solid symbols) and vegetation utilization rate (UR) (a,b, open symbols, each symbol was the average value for all grazing years). Nonlinear relationship: stocking rates with aboveground biomass production, solid line y = 168.56 + 67.3/(1 + e(−(x−6.27)/−0.15)); stocking rates with belowground root production, solid line y = 45.92 + 205.53/(1 + ((x−4.68)/1.47)2); stocking rates with UR, short dashed line y = 0.26 + 0.41/(1 + e(−(x−5.3)/0.82)).
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f3: The relationship between stocking rates and aboveground biomass production (a, solid symbols), belowground root production (b, solid symbols) and vegetation utilization rate (UR) (a,b, open symbols, each symbol was the average value for all grazing years). Nonlinear relationship: stocking rates with aboveground biomass production, solid line y = 168.56 + 67.3/(1 + e(−(x−6.27)/−0.15)); stocking rates with belowground root production, solid line y = 45.92 + 205.53/(1 + ((x−4.68)/1.47)2); stocking rates with UR, short dashed line y = 0.26 + 0.41/(1 + e(−(x−5.3)/0.82)).

Mentions: Standing root biomass was affected by grazing regimes and also showed marked seasonal variations throughout the grazing periods (p < 0.05; Fig.1d). When averaged across all dates, there was no difference in the standing root biomass between RHM and RMH (Duncan’s multiple-range tests, p > 0.05) but it was significantly higher compared with MMM (p < 0.05; Fig.1d). Also, no difference was observed between HHH and HHM (p > 0.05), which showed the lowest average standing root biomass. The root mass was largely restricted to the top soil zone, with more than 85% root distributing in the 0-10 cm soil layer for each treatment. Grazing exerted a significant influence on belowground root production (F4,10 = 16.8, p < 0.05; Fig. 1e) and turnover (F4,10 = 5.5, p < 0.05; Fig. 1f).The root production and turnover of MMM were both significantly higher than other regimes (Duncan’s multiple-range tests, p < 0.05). HHH and HHM showed no difference in root production (p > 0.05), but were significantly lower than the two deferred grazing regimes (p < 0.05; Fig. 1e,f). The vegetation UR showed a consistent increase with increasing stocking rates, whereas the aboveground production was relatively stable at stocking rates below ~5.4 SE/ha with a sharp decline after that (Fig. 3a). The root production had a different response to stocking rate compared to aboveground production, increasing to a peak at approximately ~4.5 SE/ha and then decreased (Fig. 3b).


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)

The relationship between stocking rates and aboveground biomass production (a, solid symbols), belowground root production (b, solid symbols) and vegetation utilization rate (UR) (a,b, open symbols, each symbol was the average value for all grazing years). Nonlinear relationship: stocking rates with aboveground biomass production, solid line y = 168.56 + 67.3/(1 + e(−(x−6.27)/−0.15)); stocking rates with belowground root production, solid line y = 45.92 + 205.53/(1 + ((x−4.68)/1.47)2); stocking rates with UR, short dashed line y = 0.26 + 0.41/(1 + e(−(x−5.3)/0.82)).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f3: The relationship between stocking rates and aboveground biomass production (a, solid symbols), belowground root production (b, solid symbols) and vegetation utilization rate (UR) (a,b, open symbols, each symbol was the average value for all grazing years). Nonlinear relationship: stocking rates with aboveground biomass production, solid line y = 168.56 + 67.3/(1 + e(−(x−6.27)/−0.15)); stocking rates with belowground root production, solid line y = 45.92 + 205.53/(1 + ((x−4.68)/1.47)2); stocking rates with UR, short dashed line y = 0.26 + 0.41/(1 + e(−(x−5.3)/0.82)).
Mentions: Standing root biomass was affected by grazing regimes and also showed marked seasonal variations throughout the grazing periods (p < 0.05; Fig.1d). When averaged across all dates, there was no difference in the standing root biomass between RHM and RMH (Duncan’s multiple-range tests, p > 0.05) but it was significantly higher compared with MMM (p < 0.05; Fig.1d). Also, no difference was observed between HHH and HHM (p > 0.05), which showed the lowest average standing root biomass. The root mass was largely restricted to the top soil zone, with more than 85% root distributing in the 0-10 cm soil layer for each treatment. Grazing exerted a significant influence on belowground root production (F4,10 = 16.8, p < 0.05; Fig. 1e) and turnover (F4,10 = 5.5, p < 0.05; Fig. 1f).The root production and turnover of MMM were both significantly higher than other regimes (Duncan’s multiple-range tests, p < 0.05). HHH and HHM showed no difference in root production (p > 0.05), but were significantly lower than the two deferred grazing regimes (p < 0.05; Fig. 1e,f). The vegetation UR showed a consistent increase with increasing stocking rates, whereas the aboveground production was relatively stable at stocking rates below ~5.4 SE/ha with a sharp decline after that (Fig. 3a). The root production had a different response to stocking rate compared to aboveground production, increasing to a peak at approximately ~4.5 SE/ha and then decreased (Fig. 3b).

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