scholarly journals Changes in Soil Organic Carbon and Total Nitrogen at a Small Watershed Scale as the Result of Land Use Conversion on the Loess Plateau

2018 ◽  
Vol 10 (12) ◽  
pp. 4757 ◽  
Author(s):  
Zhijing Xue ◽  
Shaoshan An
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Loess Plateau ◽  
Total Nitrogen ◽  
Land Uses ◽  
The Loess Plateau ◽  
Total N ◽  
Organic Carbon Storage ◽  
Natural Grassland

Soil organic carbon (SOC) and total nitrogen (total N) are important soil components for agricultural production. Soil quality is related to the total amount of SOC and total N sequestered in the soil. Land use plays a major role in the distribution and amount of SOC and total N. This study analyses the amount of SOC and total N under various land cover types in 1987, 2005 and 2010, and evaluated their storage in land use conversions in a comprehensively managed watershed on the Loess Plateau, China. Results show that concentrations of SOC and total N in shrub land and natural grassland areas were significantly higher than for other land uses (farmland, orchard, abandoned farmland, manmade grassland) while cropland had the lowest concentration. Storage of SOC and total N increased along the revegetation chronosequence. As the storage of SOC in 2005 and 2010, they were 3461.86 × 108 and 4504.04 × 108 g respectively. Soil organic carbon storage were enhanced one third just during 5 years. The effects of land use on SOC and total N were the most significant in the upper soil layers. The correlation between SOC, total N, and the C/N ratio indicated that the best combination of land uses were natural grassland and shrub land. They efficiently influenced the distribution and storage of SOC and total N, and benefited vegetation restoration.

The chemical and physical stability soil organic carbon in the top 1 m of the soil profile under different land uses in the UK

2020 ◽  
Author(s):  
Dedy Antony ◽  
Jo Clark ◽  
Chris Collins ◽  
Tom Sizmur
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Profile ◽  
Soil Depth ◽  
Physical Stability ◽  
Silty Clay ◽  
Land Uses ◽  
Total N

<p>Soils are the largest terrestrial pool of organic carbon and it is now known that as much as 50% of soil organic carbon (SOC) can be stored below 30 cm. Therefore, knowledge of the mechanisms by which soil organic carbon is stabilised at depth and how land use affects this is important.</p><p>This study aimed to characterise topsoil and subsoil SOC and other soil properties under different land uses to determine the SOC stabilisation mechanisms and the degree to which SOC is vulnerable to decomposition. Samples were collected under three different land uses: arable, grassland and deciduous woodland on a silty-clay loam soil and analysed for TOC, pH, C/N ratio and texture down the first one metre of the soil profile. Soil organic matter (SOM) physical fractionation and the extent of fresh mineral surfaces were also analysed to elucidate SOM stabilisation processes.</p><p>Results showed that soil texture was similar among land uses and tended to become more fine down the soil profile, but pH did not significantly change with soil depth. Total C, total N and C/N ratio decreased down the soil profile and were affected by land use in the order woodland > grassland > arable. SOM fractionation revealed that the free particulate organic matter (fPOM) fraction was significantly greater in both the topsoil and subsoil under woodland than under grassland or arable. The mineral associated OC (MinOC) fraction was proportionally greater in the subsoil compared to topsoil under all land uses: arable > grassland > woodland. Clay, Fe and Mn availability play a significant role (R<sup>2</sup>=0.87) in organic carbon storage in the top 1 m of the soil profile.</p><p>It is evidently clear from the findings that land use change has a significant effect on the dynamics of the SOC pool at depth, related to litter inputs to the system.</p>

scholarly journals Revegetation pattern affecting accumulation of organic carbon and total nitrogen in reclaimed mine soils

2019 ◽  
Author(s):  
Ping P Zhang ◽  
Yan L Zhang ◽  
Jun C Jia ◽  
Yong X Cui ◽  
Xia Wang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Loess Plateau ◽  
Total Nitrogen ◽  
Land Reclamation ◽  
Arid Area ◽  
Mine Soils ◽  
The Loess Plateau ◽  
Mine Sites ◽  
Soc Stocks

Selecting optimal revegetation patterns, i.e., patterns that are more effective for soil organic carbon (SOC) and total nitrogen (TN) accumulation is particularly important for mine land reclamation. However, there have been few evaluations of the effects of different revegetation patterns on the SOC and TN in reclaimed mine soils on the Loess Plateau, China. In this study, the SOC and TN stocks were investigated at reclaimed mine sites (RMSs), including artificially revegetated sites (ARSs) (arbors [Ar], bushes [Bu], arbor-bush mixtures [AB], and grasslands [Gr]) and a natural recovery site (NRS), as well as at undisturbed native sites (UNSs). Overall, the SOC and TN stocks in the RMSs were lower than those in the UNSs over 10–13 years after reclamation. Except for those in Ar, the SOC and TN stocks in the ARSs were significantly larger than those in the NRS. Compared with those in the NRS, the total SOC stocks in the 100 cm soil interval increased by 51.4%, 59.9%, and 109.9% for Bu, AB, and Gr, respectively, and the TN stocks increased by 33.1%, 35.1%, and 57.9%. The SOC stocks in the 0 – 100 cm soil interval decreased in the order of Gr (3.78 kg m –2) > AB (2.88 kg m–2) ≥ Bu (2.72 kg m–2), and the TN stocks exhibited a similar trend. These results suggest that grasslands were more favorable than woodlands for SOC and TN accumulation in this arid area, especially in Ar. Thus, in terms of the accumulation of SOC and TN, grassland planting is recommended as a revegetation pattern for areas with reclaimed mine soils.

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