Paddy soils have a much higher microbial biomass content than upland soils: A review of the origin, mechanisms, and drivers

2022 ◽  
Vol 326 ◽  
pp. 107798
Author(s):  
Liang Wei ◽  
Tida Ge ◽  
Zhenke Zhu ◽  
Rongzhong Ye ◽  
Josep Peñuelas ◽  
...  
2011 ◽  
Vol 77 (17) ◽  
pp. 6109-6116 ◽  
Author(s):  
Andrea Bannert ◽  
Kristina Kleineidam ◽  
Livia Wissing ◽  
Cornelia Mueller-Niggemann ◽  
Vanessa Vogelsang ◽  
...  

ABSTRACTIn many areas of China, tidal wetlands have been converted into agricultural land for rice cultivation. However, the consequences of land use changes for soil microbial communities are poorly understood. Therefore, we investigated bacterial and archaeal communities involved in inorganic nitrogen turnover (nitrogen fixation, nitrification, and denitrification) based on abundances and relative species richness of the corresponding functional genes along a soil chronosequence ranging between 50 and 2,000 years of paddy soil management compared to findings for a tidal wetland. Changes in abundance and diversity of the functional groups could be observed, reflecting the different chemical and physical properties of the soils, which changed in terms of soil development. The tidal wetland was characterized by a low microbial biomass and relatively high abundances of ammonia-oxidizing microbes. Conversion of the tidal wetlands into paddy soils was followed by a significant increase in microbial biomass. Fifty years of paddy management resulted in a higher abundance of nitrogen-fixing microbes than was found in the tidal wetland, whereas dominant genes of nitrification and denitrification in the paddy soils showed no differences. With ongoing rice cultivation, copy numbers of archaeal ammonia oxidizers did not change, while that of their bacterial counterparts declined. ThenirKgene, coding for nitrite reductase, increased with rice cultivation time and dominated its functionally redundant counterpart,nirS, at all sites under investigation. Relative species richness showed significant differences between all soils with the exception of the archaeal ammonia oxidizers in the paddy soils cultivated for 100 and 300 years. In general, changes in diversity patterns were more pronounced than those in functional gene abundances.


Soil Research ◽  
2009 ◽  
Vol 47 (3) ◽  
pp. 261 ◽  
Author(s):  
Wenjuan Sun ◽  
Yao Huang ◽  
Wen Zhang ◽  
Yongqiang Yu

Cropland may play a significant role in mitigating climate change by sequestering atmospheric CO2. To evaluate the extent of carbon sequestration, an examination of the changes in soil organic carbon (SOC) is essential. We compiled data from 50 published papers that reported changes in the SOC in eastern China over an area of 17.9 Mha. These data covered 76% of the total cropland in this area, with >8500 soil sample measurements. Changes in SOC density (ΔDoc ) in cultivated layers (Ap horizon) were estimated on the basis of the administrative regions and soil usage (paddy and upland soils), respectively. Linear relationships between ΔDoc in topsoil (Ap and P horizons, P horizon refers to the sub-cultivated layer) and in the Ap horizon were established to estimate the changes in topsoil organic carbon density. Changes in the SOC stock were determined from the acreage-weighted ΔDoc . Results indicated that the topsoil organic carbon density of croplands in eastern China increased by 5.78 t C/ha between 1980 and 2000, ranging from 4.24 to 7.49 t C/ha. The SOC stock increased by 75.4–134.1 Tg with an average of 103.5 Tg. Paddy soils, comprising 51.7% of the cropland area, accounted for ~70% of the total increase. The SOC increase in the Ap horizon accounted for ~88% (upland soils) and 71% (paddy soils) of that in the topsoil, respectively. The increase in SOC may be attributed to an increased biomass (e.g. residue retainment) input into soils due to increased crop net primary production.


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