Soil aggregate–associated mercury (Hg) and organic carbon distribution and microbial community characteristics under typical farmland–use types

Chemosphere ◽  
2021 ◽  
Vol 275 ◽  
pp. 129987
Author(s):  
Penggang Pei ◽  
Tao Sun ◽  
Yingming Xu ◽  
Yuebing Sun
2021 ◽  
Vol 13 (3) ◽  
pp. 1541
Author(s):  
Xiaolin Shen ◽  
Lili Wang ◽  
Qichen Yang ◽  
Weiming Xiu ◽  
Gang Li ◽  
...  

Our study aimed to provide a scientific basis for an appropriate tillage management of wheat-maize rotation system, which is beneficial to the sustainable development of agriculture in the fluvo-aquic soil areas in China. Four tillage treatments were investigated after maize harvest, including rotary tillage with straw returning (RT), deep ploughing with straw returning (DP), subsoiling with straw returning (SS), and no tillage with straw mulching (NT). We evaluated soil organic carbon (SOC), dissolved organic carbon (DOC), permanganate oxidizable carbon (POXC), microbial biomass carbon (MBC), and particulate organic carbon (POC) in bulk soil and soil aggregates with five particle sizes (>5 mm, 5–2 mm, 2–1 mm, 1–0.25 mm, and <0.25 mm) under different tillage managements. Results showed that compared with RT treatment, NT treatment not only increased soil aggregate stability, but also enhanced SOC, DOC, and POC contents, especially those in large size macroaggregates. DP treatment also showed positive effects on soil aggregate stability and labile carbon fractions (DOC and POXC). Consequently, we suggest that no tillage or deep ploughing, rather than rotary tillage, could be better tillage management considering carbon storage. Meanwhile, we implied that mass fractal dimension (Dm) and POXC could be effective indicators of soil quality, as affected by tillage managements.


2008 ◽  
Vol 65 (3) ◽  
pp. 543-548 ◽  
Author(s):  
Yves T Prairie

In this perspective article, I argue that dissolved organic carbon occupies a central role in the functioning of lake ecosystems, comparable in importance to that played by nutrients. Because lakes receive so much dissolved organic carbon from the terrestrial landscape, its accumulation in water bodies usually represents the largest pool of lacustrine organic matter within the water column. The transformation of even a small fraction of this external carbon by the microbial community can alter significantly the metabolic balance of lake ecosystems, simultaneously releasing carbon dioxide to the atmosphere and burying organic carbon in lake sediments. At the landscape level, even if they occupy a small fraction of the landscape, lakes play a surprisingly important role in the regional carbon budget, particularly when considered at the appropriate temporal scale.


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