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Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence.

Wang P, Liu Y, Li L, Cheng K, Zheng J, Zhang X, Zheng J, Joseph S, Pan G - Sci Rep (2015)

Bottom Line: While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils.Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization.This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation.

View Article: PubMed Central - PubMed

Affiliation: Institute of Resource, Ecosystem and Environment of Agriculture, and Department of Soil Science, Nanjing Agricultural University, Nanjing 210095, China.

ABSTRACT
Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist.

No MeSH data available.


Related in: MedlinePlus

Inter-correlation between bacterial abundance and particulate organic carbon as well as soil microbial activity.Bacterial abundance as a function of total soil organic carbon (a) and a function of particulate organic carbon (b); Soil respiration as a function of bacterial abundance (c); Bacterial abundance scaled soil respiration (d) and normalized enzyme activity (e) respectively as a function of bacterial abundance. Values in the mean ± SD, n = 3.
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f2: Inter-correlation between bacterial abundance and particulate organic carbon as well as soil microbial activity.Bacterial abundance as a function of total soil organic carbon (a) and a function of particulate organic carbon (b); Soil respiration as a function of bacterial abundance (c); Bacterial abundance scaled soil respiration (d) and normalized enzyme activity (e) respectively as a function of bacterial abundance. Values in the mean ± SD, n = 3.

Mentions: The content of microbial biomass carbon (MBC) ranged from 63 mg kg−1 in P0 to 532 mg kg−1 at P100, being several times higher in the rice soils than the uncultivated salt marsh (Table 3). With prolonged rice cultivation, MBC content decreased to 450 mg kg−1 in P700. Bacterial gene copy numbers ranged from 4 × 108 copies g−1soil to 10 × 109 copies g−1soil while fungal copy numbers from 9 × 106 copies g−1soil to 17 × 106 copies g−1soil. Gene copy numbers of bacteria, the majority of soil microbial population, was significantly higher in rice soils than in uncultivated salt marsh and increased consistently with prolonged rice cultivation over the centuries. In addition, the Shannon index of bacterial diversity was increased at P50 and P100 but did not significantly change with prolonged rice cultivation (Table 3). Bacterial gene copy number was exponentially correlated to total SOC accumulation (Fig. 2a) and was positively linearly correlated to the size of POC pool (Fig. 2b). There were no discernible changes in the gene copy number and in Shannon index of fungal communities (Table 3) over the rice soils P50-P700. Nor was fungal gene abundance significantly correlated to total SOC content across the chronosequence.


Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence.

Wang P, Liu Y, Li L, Cheng K, Zheng J, Zhang X, Zheng J, Joseph S, Pan G - Sci Rep (2015)

Inter-correlation between bacterial abundance and particulate organic carbon as well as soil microbial activity.Bacterial abundance as a function of total soil organic carbon (a) and a function of particulate organic carbon (b); Soil respiration as a function of bacterial abundance (c); Bacterial abundance scaled soil respiration (d) and normalized enzyme activity (e) respectively as a function of bacterial abundance. Values in the mean ± SD, n = 3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4622084&req=5

f2: Inter-correlation between bacterial abundance and particulate organic carbon as well as soil microbial activity.Bacterial abundance as a function of total soil organic carbon (a) and a function of particulate organic carbon (b); Soil respiration as a function of bacterial abundance (c); Bacterial abundance scaled soil respiration (d) and normalized enzyme activity (e) respectively as a function of bacterial abundance. Values in the mean ± SD, n = 3.
Mentions: The content of microbial biomass carbon (MBC) ranged from 63 mg kg−1 in P0 to 532 mg kg−1 at P100, being several times higher in the rice soils than the uncultivated salt marsh (Table 3). With prolonged rice cultivation, MBC content decreased to 450 mg kg−1 in P700. Bacterial gene copy numbers ranged from 4 × 108 copies g−1soil to 10 × 109 copies g−1soil while fungal copy numbers from 9 × 106 copies g−1soil to 17 × 106 copies g−1soil. Gene copy numbers of bacteria, the majority of soil microbial population, was significantly higher in rice soils than in uncultivated salt marsh and increased consistently with prolonged rice cultivation over the centuries. In addition, the Shannon index of bacterial diversity was increased at P50 and P100 but did not significantly change with prolonged rice cultivation (Table 3). Bacterial gene copy number was exponentially correlated to total SOC accumulation (Fig. 2a) and was positively linearly correlated to the size of POC pool (Fig. 2b). There were no discernible changes in the gene copy number and in Shannon index of fungal communities (Table 3) over the rice soils P50-P700. Nor was fungal gene abundance significantly correlated to total SOC content across the chronosequence.

Bottom Line: While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils.Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization.This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation.

View Article: PubMed Central - PubMed

Affiliation: Institute of Resource, Ecosystem and Environment of Agriculture, and Department of Soil Science, Nanjing Agricultural University, Nanjing 210095, China.

ABSTRACT
Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist.

No MeSH data available.


Related in: MedlinePlus