scholarly journals Effects of Plum Plantation Ages on Soil Organic Carbon Mineralization in the Karst Rocky Desertification Ecosystem of Southwest China

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1107 ◽  
Author(s):  
Hui Yang ◽  
Biqin Mo ◽  
Mengxia Zhou ◽  
Tongbin Zhu ◽  
Jianhua Cao

Soil organic carbon (SOC) mineralization is closely related to carbon source or sink of terrestrial ecosystem. Understanding SOC mineralization under plum plantation is essential for improving our understanding of SOC responses to land-use change in karst rocky desertification ecosystem. In this study, 2-year, 5-year, and 20-year plum plantations and adjacent abandoned land dominated by herbs were sampled, and a 90-day incubation experiment was conducted to investigate the effect of plum plantations with different ages on SOC mineralization in subtropical China. Results showed that: (1) Plum plantation significantly decreased SOC content compared with abandoned land, but there was no significant difference in SOC content among plum plantations with different ages. Oppositely, the accumulative SOC mineralization (Ct) and potential SOC mineralization (C0) showed different responses to plum plantation ages. (2) The dynamics of the SOC mineralization were a good fit to a first-order kinetic model. Both C0 and Ct in calcareous soil of this study was several- to 10-folds lower than other soils in non-karst regions, indicating that SOC in karst regions has higher stability. (3) Correlation analysis revealed that both Ct and C0 was significantly correlated with soil calcium (Ca), suggesting an important role of Ca in SOC mineralization in karst rocky desertification areas. In conclusion, a Ca-rich geological background controls SOC mineralization in karst rocky desertification areas.

Author(s):  
Hui Yang ◽  
Biqin Mo ◽  
Mengxia Zhou ◽  
Tongbin Zhu ◽  
Jianhua Cao

Soil organic carbon (SOC) mineralization is closely related to carbon source or sink of terrestrial ecosystem. Understanding soil organic carbon (SOC) mineralization under plum plantation is essential for improving our understanding of SOC responses to land-use change in karst rocky desertification ecosystem. In this study, 2-y, 5-y and 20-y plum plantations and adjacent woodland were sampled and a 90-day incubation experiment was conducted to investigate the effect of plum plantation with different years on SOC mineralization in subtropical China. Results showed that: (1) there was no significant difference in SOC content between different planting years, but there were significant differences in accumulative SOC mineralization (Ct) and potential SOC mineralization (C0); (2) the dynamics of the SOC mineralization was a good fit to a first-order kinetic model. Both C0 and Ct in calcareous soil of this study was several to ten folds lower than that in other soils, indicating that SOC in karst region has higher stability. (3) Correlation analysis revealed that both Ct and C0 was significantly correlated with soil calcium (Ca) and C/N, indicating the important role of Ca and C/N in SOC mineralization in karst rocky desertification area.


2021 ◽  
Author(s):  
Xiong Fang ◽  
Haozhao Sun ◽  
Yunpeng Huang ◽  
Jundi Liu ◽  
Yulin Zhu ◽  
...  

Abstract Background and aims Soil organic carbon (SOC) mineralization produces important CO2 flux from terrestrial ecosystems which can provide feedbacks to climates. Vegetation restoration can affect SOC mineralization and its temperature sensitivity (Q10), but how this effect is related to soil moisture remains uncertain. Methods We performed a laboratory incubation using soils of different vegetation restoration stages (i.e., degraded vegetation [DS], plantation [PS], and secondary natural forest [SFS]) maintained under different moisture and temperature conditions to explore the combined effects of vegetation restoration and soil moisture on SOC mineralization and Q10. Results We found that cumulative SOC mineralization in PS and SFS were about 11.7 times higher than that in the DS, associated with higher SOC content and microbial biomass. Increased soil moisture and temperature led to higher SOC mineralization in the SFS and PS. However, in the DS, soil moisture did not affect SOC mineralization, but temperature enhancement solely increased (158.7%) SOC mineralization at the 60%MWHC treatment. Furthermore, significant interactive effect of vegetation restoration and soil moisture on Q10 was detected. At the 60%MWHC treatment, Q10 declined with vegetation restoration age. Nevertheless, at the 30%MWHC treatment, Q10 was lower in the DS than that in the PS. Higher soil moisture did not affect Q10 in the PS and SFS, but enhanced Q10 in the DS. Conclusions Our results highlight that the responses of SOC mineralization and Q10 to vegetation restoration were highly dependent on soil moisture and substrate availability, and vegetation restoration reduced the influence of soil moisture on Q10.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Hongtao Wu ◽  
Jinli Hu ◽  
Muhammad Shaaban ◽  
Peng Xu ◽  
Jinsong Zhao ◽  
...  

Abstract Background The size of lime material is vital for the efficiency of ameliorating soil acidity, thereby influencing soil biochemical processes. However, the effects of different sized lime material application on soil organic carbon (SOC) mineralization are yet to be elucidated. Therefore, a 35-day incubation experiment was conducted to determine the effects of three particle size fractions (0.5 to 0.25, 0.25 to 0.15, and < 0.15 mm) of dolomite on SOC mineralization of two acidic paddy soils. Results CO2 emission was increased by 3–7%, 11–21%, and 32–49% for coarse-, medium-, and fine-sized dolomite treatments, respectively, compared to the control in both soils. They also well conformed to a first-order model in all treatments, and the estimated decomposition rate constant was significantly higher in the fine-sized treatment than that of other treatments (P < 0.05), indicating that SOC turnover rate was dependent on the dolomite size. The finer particle sizes were characterized with higher efficiencies of modifying soil pH, consequently resulting in higher dissolved organic carbon contents and microbial biomass carbon, eventually leading to higher CO2 emissions. Conclusions The results demonstrate that the size of dolomite is a key factor in regulating SOC mineralization in acidic paddy soils when dolomite is applied to manipulate soil pH.


2021 ◽  
Vol 13 (7) ◽  
pp. 3790
Author(s):  
Xiang Ma ◽  
Qingqing Zhang ◽  
Haibing Wu ◽  
Jing Liang

It is important to understand the dynamics of soil carbon to study the effects of waste amendment inputs on soil organic carbon decomposition. The aim of this study was to evaluate the effect of waste amendment carbon input on the soil organic carbon (SOC) content, soil particulate organic carbon (POC) content and soil organic carbon mineralization rate dynamics. A 60-day experiment was carried out in the laboratory. The following treatments were compared: (1) CK: soil without amendments; (2) FW1: soil with food waste compost (soil/food waste compost = 100:1); (3) FW2: soil with food waste compost (soil/food waste compost = 100:2); (4) GW1: soil with garden waste compost (soil/garden waste compost = 100:0.84); (5) GW2: soil with garden waste compost (soil/garden waste compost = 100:1.67); (6) FGW1: soil amendments mixture (soil/food waste compost/garden waste compost = 100:0.5:0.42); (7) FGW2: soil amendments mixture (soil/food waste compost/garden waste compost = 100:1:0.84); the inputs of amendment carbon to FW1, GW1 and FGW1 were 2.92 g kg−1, the inputs of amendment carbon to FW2, GW2 and FGW2 were 5.84 g kg−1. The results showed that the addition of waste amendments increased the amount of cumulative mineralization from 95% to 262% and accelerated the rate of soil mineralization. After adding organic materials, the change in the soil organic carbon mineralization rate could be divided into two stages: the fast stage and the slow stage. The dividing point of the two stages was approximately 10 days. When equal amounts of waste amendment carbon were input to the soil, there was no significant difference in SOC between food waste and garden waste. However, SOC increased with the amount of amendment addition. However, for POC, there was no significant difference between the different amounts of carbon input to the garden waste compost treatments. SOC and POC were significantly correlated with the cumulative emissions of CO2.


BioResources ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 9957-9967
Author(s):  
Gang Xu ◽  
Jiawei Song ◽  
Yang Zhang ◽  
Yingchun Lv

Intense droughts and extreme precipitation events are likely to occur more frequently with global climate change. These drying-rewetting (DW) cycles affect the soil carbon (C) cycle. Biochar addition are reported to affect SOC mineralization and soil organic carbon (SOC) storage. However, the effects of biochar application on SOC mineralization during DW cycles are poorly understood. Two wheat straw (WS25) biochar produced at 300 °C (WS300) and 600 °C (WS600) were used to explore the effects of biochar on SOC mineralization under artificial DW cycles as compared to constant moisture (CM). It was found that biochar had different effects on SOC mineralization depending on biochar type or drying/rewetting period of DW cycles. Just like CK and WS25, WS600 application decreased SOC mineralization under DW cycles compared to CM. To some extent, SOC mineralization during DW cycles was similar to CM for WS300. The results suggested that WS300 addition diminished the reducing effect of DW cycle on SOC mineralization. In addition, biochar exhibited different effects on SOC mineralization depending on the drying and rewetting period under DW cycles. Biochar (WS300) addition during the drying period had less effect on SOC mineralization but increased the flush effect of SOC mineralization during the rewetting period. In conclusions, biochar application significantly affect SOC mineralization following DW cycles.


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