scholarly journals Dynamics of Soil Organic Carbon and Aggregate Stability with Grazing Exclusion in the Inner Mongolian Grasslands

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0146757 ◽  
Author(s):  
Ding Wen ◽  
Nianpeng He ◽  
Jinjing Zhang
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.


2019 ◽  
Vol 37 (3) ◽  
pp. 263-273
Author(s):  
Efraín Francisco Visconti-Moreno ◽  
Ibonne Geaneth Valenzuela-Balcázar

The stability of soil aggregates depends on the organic matter, and the soil use and management can affect the soil organicmatter (SOM) content. Therefore, it is necessary to know therelationship between aggregate stability and the content of SOMin different types of soil use at two different altitudes of theColombian Andes. This study examined the conditions of soilaggregate stability expressed as a distribution of the size classes of stable aggregates (SA) and of the mean weighted diameter of the stable aggregates (MWD). To correlate these characteristics with the soil organic carbon (OC), we measured the particulate organic matter pool (POC), the OC associated with the mineral organic matter pool (HOC), the total organic carbon content (TOC), and the humification rate (HR). Soils were sampled at two altitudes: 1) Humic Dystrudepts in a cold tropical climate (CC) with three plots: tropical mountain rainforest, pastures, and crops; 2) Fluvaquentic Dystrudepts in a warm tropical climate (WC) with three plots: tropical rainforest, an association of oil palm and pastures, and irrigated rice. Soils were sampled at three depths: 0-5, 5-10 and 10-20 cm. The physical properties, mineral particle size distribution, and bulk density were measured. The content of SA with size>2.36 mm was higher in the CC soil (51.48%) than in the WC soil (9.23%). The SA with size 1.18-2.36 mm was also higher in the CC soil (7.78%) than in the WC soil (0.62%). The SA with size 0.60-1.18 mm resulted indifferent. The SA with size between 0.30 and 0.60 mm were higher in the WC soil (13.95%) than in the CC soil (4.67%). The SA<0.30 mm was higher in the WC soil (72.56%) than in the CC soil (32.15%). It was observed that MWD and the SA>2.36 mm increased linearly with a higher POC, but decreased linearly with a higher HR. For the SA<0.30 mm, a linear decrease was observed at a higher POC, while it increased at a higher HR.


2020 ◽  
Vol 32 (1) ◽  
pp. 355-362 ◽  
Author(s):  
Qicong Wu ◽  
Xianghe Jiang ◽  
Qianwen Lu ◽  
Jinbiao Li ◽  
Jinlin Chen

2020 ◽  
Author(s):  
Svenja Roosch ◽  
Vincent Felde ◽  
Daniel Uteau ◽  
Stephan Peth

&lt;p&gt;Soil microaggregates are considered to play an important role in soil functioning and soil organic carbon (SOC) is of great importance for the formation and stabilization of these aggregates. The loss of SOC can occur, for example, after a change in land use and may lead to a decreased aggregate stability, which makes soils vulnerable to various threats, such as erosion or compaction. It is therefore important to understand the effect of SOC loss on aggregate stability in order to better understand and preserve the functioning of healthy soils.&lt;/p&gt;&lt;p&gt;We sampled two adjacent plots from a loess soil in Selhausen (North Rhine-Westphalia, Germany) in November of 2019 and measured aggregate stability and architecture of soil microaggregates. One plot was kept free from vegetation by the application of herbicides and by tillage (to a depth of 5&amp;#160;cm) from 2005 on, while the other plot was used for agriculture (conventional tillage). Over the course of 11 years, the SOC concentration in the bulk soil was reduced from 12.2 to 10.1&amp;#160;g SOC kg&lt;sup&gt;-1&lt;/sup&gt; soil. We took 10 undisturbed soil cores from two depths of each plot (Ap and Bt horizons).&lt;/p&gt;&lt;p&gt;The stability of aggregates against hydraulic and mechanical stresses was tested using the widespread wet sieving approach and a newly developed dry crushing approach. Isolated microaggregates gained from the latter procedure were tested against tensile stress by adapting a crushing test in a load frame to the microaggregate scale. To shed light on the effect of a decreased SOC content on microaggregate structure, we scanned several microaggregates with a high-resolution computed tomography scanner (Zeiss Xradia 520 versa) at sub-micron resolutions and analyzed the features of their pore systems.&lt;/p&gt;&lt;p&gt;This will give us valuable insights into the interplay of mechanical and physicochemical stability, as well as the structural properties of microaggregates with regard to SOC depletion. The consequences for various soil functions provided by microaggregates, like the habitat function for microorganisms or their capacity to store and transport gas, water and nutrients, are discussed.&lt;/p&gt;


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