Time-Scale Variation of Organic Carbon in Paddy Soil in Sanjiang Plain, China

2022 ◽  
pp. 43-46
Author(s):  
Wang Qiuju ◽  
Liu Feng ◽  
Chi Fengqin
Keyword(s):  
Organic Carbon ◽  
Paddy Soil ◽  
Time Scale ◽  
Sanjiang Plain ◽  
Scale Variation

Phanerozoic Oxygen

2017 ◽  
Author(s):  
Donald Eugene Canfield
Keyword(s):  
Oxygen Consumption ◽  
Organic Carbon ◽  
Sea Level ◽  
Time Scale ◽  
Atmospheric Oxygen ◽  
Sea Level Change ◽  
Oxygen Production ◽  
Level Change ◽  
History Of ◽  
Geologic Processes

This chapter discusses the modeling of the history of atmospheric oxygen. The most recently deposited sediments will also be the most prone to weathering through processes like sea-level change or uplift of the land. Thus, through rapid recycling, high rates of oxygen production through the burial of organic-rich sediments will quickly lead to high rates of oxygen consumption through the exposure of these organic-rich sediments to weathering. From a modeling perspective, rapid recycling helps to dampen oxygen changes. This is important because the fluxes of oxygen through the atmosphere during organic carbon and pyrite burial, and by weathering, are huge compared to the relatively small amounts of oxygen in the atmosphere. Thus, all of the oxygen in the present atmosphere is cycled through geologic processes of oxygen liberation (organic carbon and pyrite burial) and consumption (weathering) on a time scale of about 2 to 3 million years.

Rice straw application with different water regimes stimulate enzymes activity and improve aggregates and their organic carbon contents in a paddy soil

Chemosphere ◽  
2021 ◽  
Vol 274 ◽  
pp. 129971
Author(s):  
Ibrahim Mohamed ◽  
Mohamed A. Bassouny ◽  
Mohamed H.H. Abbas ◽  
Zhan Ming ◽  
Cao Cougui ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Rice Straw ◽  
Paddy Soil ◽  
Water Regimes ◽  
Enzymes Activity ◽  
Straw Application

Effect of Tillage Systems on Soil Organic Carbon and Soil Quality in a Purple Paddy Soil

2011 ◽  
Vol 183-185 ◽  
pp. 1190-1194
Author(s):  
Jun Ke Zhang ◽  
Qing Ju Hao ◽  
Chang Sheng Jiang ◽  
Yan Wu
Keyword(s):  
Organic Carbon ◽  
Soil Quality ◽  
Paddy Soil ◽  
Conventional Tillage ◽  
Water Infiltration ◽  
Purple Soil ◽  
Tillage Systems ◽  
Field Station ◽  
No Till ◽  
The Impact

The impact of conservation tillage practices on carbon sequestration has been of great interest in recent years. This experiment analyzed the organic carbon status of soils sampled at depth increments from 0 to 60 cm after 20 years in a purple paddy soil. The tillage experiment was established in the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China, located in the farm of Southwest University (30°26′N, 106°26′E), Chongqing. In this paper, five tillage treatments including conventional tillage with rice only system (DP), conventional tillage with rotation of rice and rape system (SL), no-till and ridge culture with rotation of rice and rape system (LM), no-till and plain culture with rotation of rice and rape system (XM) and tillage and ridge culture with rotation of rice and rape system (LF) were selected as research objectives to measure SOC storage and stratification ratio of SOC (CSR). The SOC storage under different tillage systems was calculated based on an equivalent soil mass. The CSR can be used as an indicator of soil quality because surface organic matter is essential to erosion control, water infiltration, and the conservation of nutrients. Results showed that in soil under no-till SOC was concentrated near the surface, while in tilled soil SOC decreased equably with the increase of soil depth. The difference of SOC contents between the five tillage systems was the largest in the top soil and the lowest in the bottom soil. The order of SOC storage was LM (158.52 Mg C•ha-1) >DP (106.74 Mg C•ha-1) >XM (100.11 Mg C•ha-1) >LF (93.11 Mg C•ha-1) >SL (88.59 Mg C•ha-1), LM treatment was significantly higher than the other treatments. The CSR of 0-10/50-60 cm was 2.65, 2.70 and 2.14 under LM, XM and LF treatments, while 1.54 and 1.92 under DP and SL treatments. We considered CSR>2 indicate an improvement in soil quality produced by changing from tillage to no-tillage, as well as changing from plane to ridge. Overall, long-term LM treatment is a valid strategy for increasing SOC storage and improving soil quality in a purple paddy soil in Southwest China.

Paddy Soil Profile Distribution of δ13C Subjected to Rice Straw Amendment and Burning

2019 ◽  
Vol 886 ◽  
pp. 3-7 ◽  
Author(s):  
Wutthikrai Kulsawat ◽  
Boonsom Porntepkasemsan ◽  
Phatchada Nochit
Keyword(s):  
Organic Carbon ◽  
Paddy Soil ◽  
Soil Profile ◽  
Management Practices ◽  
Soil Depth ◽  
Animal Health ◽  
Soil Samples ◽  
Residue Management ◽  
Straw Amendment ◽  
Stubble Burning

Paddy residues are the most generous agricultural biomass from the paddy cultivation, Paddy residues practices include crop residue amendment and in-situ burning. It indicated that residue amendment increased the organic carbon and nutrient contents in soil, However, an open residue burning is still a common practice in Thailand despite of strict law enforcements and proper education to farmers about its implications on soil, human and animal health The present study determined how residues management practices: residue amendment and stubble burning, influence the soil organic carbon by determining δ13C in paddy soil profile. The 30 cm depth soil samples from the naturally straw amendment and stubble burning paddy fields were collected in Chiang Khwan district, Roi-et province during 2017. The δ13C values with soil depth showed that residue management practices produce statistical differences in both soils. The δ13C values of soil samples from amendment and burning sites ranged from-23.19‰ to-17.98‰ and-24.79‰ to-19.28‰, respectively. Carbon isotopes differentiate clearly between amendment site (more positive values) and burning site (more negative values). The results from this study were in accordance with literatures which reported that the δ13C distribution in the soil profile can be applied to study in SOC dynamics as a result of different paddy residue management practices (amendment or burning). Further research is needed to confirm the validity of the stable carbon isotope technique in this type of studies.

Change in water extractable organic carbon and microbial PLFAs of biochar during incubation with an acidic paddy soil

Soil Research ◽  
2015 ◽  
Vol 53 (7) ◽  
pp. 763 ◽  
Author(s):  
Ming Li ◽  
Ming Liu ◽  
Stephen Joseph ◽  
Chun-Yu Jiang ◽  
Meng Wu ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Paddy Soil ◽  
Reduction Rate ◽  
Chemical Properties ◽  
Nutrient Status ◽  
Biological Properties ◽  
Uv Absorbance ◽  
Water Extractable Organic Carbon ◽  
Microbial Plfas ◽  
Water Extractable

Biochar has been considered to affect the transformation of soil organic carbon, soil microbial activity and diversity when applied to soil. However, the changes in chemical and biological properties of biochar itself in soil have not been fully determined. In this study, various biochar samples were obtained from three crop straws (rice, peanut and corn) and two wood chips (bamboo and pine), and incubated with an acidic paddy soil. We examined the changes of biochar water extractable organic carbon (WEOC) content and its ultraviolet (UV) absorbance at 280 nm during incubation period, and also investigated the microbial phospholipid fatty acids (PLFAs) profile of biochar after 75 days of incubation. The WEOC content of biochars decreased at the end of incubation, except for the biochar pyrolysed from bamboo chips at 400°C. An average reduction rate of 61.2% in WEOC concentration for straw biochars occurred within the first 15 days, while no significant change was observed for all biochars between day 15 and 45, and a slight increase in WEOC occurred for all biochars in the last 30 days. There was a positive relationship between biochar WEOC content and its UV absorbance properties. The microbial PLFAs concentrations of biochars varied from 15.56 to 60.35 nmol g–1, and there was a greater abundance in content and species for corn straw biochars than for the other types of biochars. General bacteria were the dominant microbial group that colonised biochar sample, while gram-positive bacterial and fungi were less in abundance. The chemical properties of fresh biochar were well correlated with total PLFAs concentrations, and significantly related to the composition of microbial community. We concluded that the WEOC component of most biochars change within such short-term application to soil, and the WEOC in combined with the pH and nutrient status of biochar, can alter the type and abundance of microorganisms that colonised biochar.

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