scholarly journals Effects of Different Particle Sizes of Hydroxyapatite on the Distribution and Migration of Trace Elements (Copper and Cadmium) in a Smelter-Impacted Soil

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Lei Xu ◽  
Xiangyu Xing ◽  
Zhenqiu Zhu ◽  
Hongbiao Cui ◽  
Jianbiao Peng ◽  
...  
Keyword(s):  
Trace Elements ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Ph ◽  
Particle Sizes ◽  
In Situ Experiment ◽  
Soil Colloid ◽  
Cd Distribution ◽  
And Migration

To study the remediation effect of hydroxyapatite with different particle sizes, a field in situ experiment was carried out by adding conventional hydroxyapatite (0.25 mm) and microhydroxyapatite (3 μm) and nanohydroxyapatite (40 nm) to the contaminated soil and planting Elsholtzia splendens. The distribution and migration of copper (Cu) and cadmium (Cd) in soil were investigated after 4 years. The results show that the application of three different particle sizes of hydroxyapatite significantly raise the soil pH, total phosphorus, and soil organic carbon. Moreover, the addition of hydroxyapatite can reduce the EXC fraction of Cu and Cd by 73.7%–80.1% and 20.8%–35.2%, respectively. In addition, the concentrations of Cu and Cd in >2 mm, 0.25–2 mm, 0.053–0.25 mm, and <0.053 mm aggregate are significantly increased. This improvement indicates that there are risks which may cause the increasing of total Cu and Cd in the soil where the pollution sources still exist. Furthermore, the content of soil colloid is significantly increased, and the colloidal Cu and Cd distribution percentage have been significantly increased by 49.9%–120% and 30.3%–181%. This result illustrates that the application of hydroxyapatite may greatly increase the possibility of colloid and dust migration of Cu and Cd.

Soil organic carbon storage by shaded and unshaded coffee systems and its implications for climate change mitigation in China

2021 ◽  
pp. 1-8
Author(s):  
Ziwei Xiao ◽  
Xuehui Bai ◽  
Mingzhu Zhao ◽  
Kai Luo ◽  
Hua Zhou ◽  
...  
Keyword(s):  
Climate Change ◽  
Linear Regression ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Multiple Linear Regression ◽  
Carbon Storage ◽  
Soil Ph ◽  
Soil Bulk Density ◽  
Soil N ◽  
And Storage

Abstract Shaded coffee systems can mitigate climate change by fixation of atmospheric carbon dioxide (CO2) in soil. Understanding soil organic carbon (SOC) storage and the factors influencing SOC in coffee plantations are necessary for the development of sound land management practices to prevent land degradation and minimize SOC losses. This study was conducted in the main coffee-growing regions of Yunnan; SOC concentrations and storage of shaded and unshaded coffee systems were assessed in the top 40 cm of soil. Relationships between SOC concentration and factors affecting SOC were analysed using multiple linear regression based on the forward and backward stepwise regression method. Factors analysed were soil bulk density (ρb), soil pH, total nitrogen of soil (N), mean annual temperature (MAT), mean annual moisture (MAM), mean annual precipitation (MAP) and elevations (E). Akaike's information criterion (AIC), coefficient of determination (R2), root mean square error (RMSE) and residual sum of squares (RSS) were used to describe the accuracy of multiple linear regression models. Results showed that mean SOC concentration and storage decreased significantly with depth under unshaded coffee systems. Mean SOC concentration and storage were higher in shaded than unshaded coffee systems at 20–40 cm depth. The correlations between SOC concentration and ρb, pH and N were significant. Evidence from the multiple linear regression model showed that soil bulk density (ρb), soil pH, total nitrogen of soil (N) and climatic variables had the greatest impact on soil carbon storage in the coffee system.

scholarly journals Soil greenhouse gas fluxes from different tree species on Taihang Mountain, North China

2014 ◽  
Vol 11 (6) ◽  
pp. 1649-1666 ◽  
Author(s):  
X. P. Liu ◽  
W. J. Zhang ◽  
C. S. Hu ◽  
X. G. Tang
Keyword(s):  
Soil Moisture ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Temperature ◽  
Soil Ph ◽  
Tree Species ◽  
Soil Bulk Density ◽  
Total N ◽  
Gas Fluxes ◽  
Greenhouse Gas Fluxes

Abstract. The objectives of this study were to investigate seasonal variation of greenhouse gas fluxes from soils on sites dominated by plantation (Robinia pseudoacacia, Punica granatum, and Ziziphus jujube) and natural regenerated forests (Vitex negundo var. heterophylla, Leptodermis oblonga, and Bothriochloa ischcemum), and to identify how tree species, litter exclusion, and soil properties (soil temperature, soil moisture, soil organic carbon, total N, soil bulk density, and soil pH) explained the temporal and spatial variation in soil greenhouse gas fluxes. Fluxes of greenhouse gases were measured using static chamber and gas chromatography techniques. Six static chambers were randomly installed in each tree species. Three chambers were randomly designated to measure the impacts of surface litter exclusion, and the remaining three were used as a control. Field measurements were conducted biweekly from May 2010 to April 2012. Soil CO2 emissions from all tree species were significantly affected by soil temperature, soil moisture, and their interaction. Driven by the seasonality of temperature and precipitation, soil CO2 emissions demonstrated a clear seasonal pattern, with fluxes significantly higher during the rainy season than during the dry season. Soil CH4 and N2O fluxes were not significantly correlated with soil temperature, soil moisture, or their interaction, and no significant seasonal differences were detected. Soil organic carbon and total N were significantly positively correlated with CO2 and N2O fluxes. Soil bulk density was significantly negatively correlated with CO2 and N2O fluxes. Soil pH was not correlated with CO2 and N2O emissions. Soil CH4 fluxes did not display pronounced dependency on soil organic carbon, total N, soil bulk density, and soil pH. Removal of surface litter significantly decreased in CO2 emissions and CH4 uptakes. Soils in six tree species acted as sinks for atmospheric CH4. With the exception of Ziziphus jujube, soils in all tree species acted as sinks for atmospheric N2O. Tree species had a significant effect on CO2 and N2O releases but not on CH4 uptake. The lower net global warming potential in natural regenerated vegetation suggested that natural regenerated vegetation were more desirable plant species in reducing global warming.

scholarly journals Contents, distribution, and fractionation of soil organic carbon and trace elements in soils under a green manure application

2020 ◽  
Vol 16 (No. 1) ◽  
pp. 50-58
Author(s):  
Yana Timofeeva ◽  
Lyudmila Purtova ◽  
Alexey Emelyanov ◽  
Maxim Burdukovskii ◽  
Irina Kiseleva ◽  
...  
Keyword(s):  
Trace Elements ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Green Manure ◽  
Mineral Soil ◽  
Water Soluble ◽  
Household Waste ◽  
Nickel Ions ◽  
Low Degree ◽  
Soluble Components

We quantified the soluble fractions of the soil organic carbon (SOC) concentrations and the total and water-soluble trace elements in soils contaminated by household waste and remediated via the addition of green manure over 13 years and identified the main factors controlling the vertical distribution and accumulation of the trace elements. Green manure favoured the active formation of soil organic matter. The SOC of the examined soils was characterised by the active stabilisation by mineral soil compounds, but by a low degree of humification. The soils showed increased concentrations of Cr and Ni ions. The SOC and different soil compounds enriched by Si, Ca, and Mn ions were the important determinant for the distribution of Sr, V and Cu ions, as well as for the distribution of Pb and Cr ions bound to the water-soluble components of the soils. The low degree of SOC humification may be one of the main reasons of the high concentrations of Cu and Pb ions in the composition of the water-soluble soil compounds. The nickel ions were mainly associated with compounds enriched by the Al and Fe ions. The extremely high percentage concentration of the Ni ions in the water-soluble components of the soils may be result of the absence of the Ni ions adsorption by humic substances.

scholarly journals Determining the Distribution and Interaction of Soil Organic Carbon, Nitrogen, pH and Texture in Soil Profiles: A Case Study in the Lancangjiang River Basin, Southwest China

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 532 ◽  
Author(s):  
Wenxiang Zhou ◽  
Guilin Han ◽  
Man Liu ◽  
Jie Zeng ◽  
Bin Liang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
River Basin ◽  
Soil Ph ◽  
Soil Texture ◽  
Soil Depth ◽  
Soil Samples ◽  
Soil Profiles ◽  
Soil Organic Nitrogen ◽  
Silty Loam

The profile distributions of soil organic carbon (SOC), soil organic nitrogen (SON), soil pH and soil texture were rarely investigated in the Lancangjiang River Basin. This study aims to present the vertical distributions of these soil properties and provide some insights about how they interact with each other in the two typical soil profiles. A total of 56 soil samples were collected from two soil profiles (LCJ S-1, LCJ S-2) in the Lancangjiang River Basin to analyze the profile distributions of SOC and SON and to determine the effects of soil pH and soil texture. Generally, the contents of SOC and SON decreased with increasing soil depth and SOC contents were higher than SON contents (average SOC vs. SON content: 3.87 g kg−1 vs. 1.92 g kg−1 in LCJ S-1 and 5.19 g kg−1 vs. 0.96 g kg−1 in LCJ S-2). Soil pH ranged from 4.50 to 5.74 in the two soil profiles and generally increased with increasing soil depth. According to the percentages of clay, silt, and sand, most soil samples can be categorized as silty loam. Soil pH values were negatively correlated with C/N ratios (r = −0.66, p < 0.01) and SOC contents (r = −0.52, p < 0.01). Clay contents were positively correlated with C/N ratios (r = 0.43, p < 0.05) and SOC contents (r = 0.42, p < 0.01). The results indicate that soil pH and clay are essential factors influencing the SOC spatial distributions in the two soil profiles.

Effects of application of poppy waste on spinach yields, soil properties, and soil carbon sequestration in southern Tasmania

Soil Research ◽  
2009 ◽  
Vol 47 (5) ◽  
pp. 478 ◽  
Author(s):  
M. A. Hardie ◽  
W. E. Cotching
Keyword(s):  
Food Safety ◽  
Carbon Sequestration ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Ph ◽  
Yield Loss ◽  
Water Infiltration ◽  
Fresh Market ◽  
Waste Products ◽  
Significant Yield

Production of fresh market salad and lettuce in southern Tasmania has reduced soil organic carbon levels, resulting in the development of surface crusts, erosion, and poor water infiltration. Options for increasing soil organic carbon under this production system are limited by strict food safety protocols which prohibit the use of composts or ‘animal’-based waste products. Poppy waste was identified as a suitable seed-free, inexpensive source of non-animal-based organic carbon. Trials were established on a Chromosol to evaluate the effects of poppy waste incorporation on soil organic carbon and production of Bocane spinach (Spinach oleracea). Application of 50–200 m3/ha of poppy waste resulted in significant yield loss (up to 57%) of seedlings planted within 8 weeks following waste incorporation. It was speculated that yield loss resulted from nitrogen drawdown; however, soil analyses demonstrated that yield loss resulted from a combination of increased soil pH and soil salinity (EC). The 200 m3/ha treatment increased soil pHwater from 7.2 before application to 8.5 and 7.7, at 4 and 22 weeks after application. Soil EC1 : 5 increased from 0.15 dS/m before application to 0.45 dS/m at 2 weeks after application, before returning to 0.15 dS/m at 22 weeks. Application of poppy waste at 200 m3/ha significantly increased soil organic carbon from 1.24% to 1.57%; however, applications at lower rates were not significant. The carbon sequestration efficiency from poppy waste to soil organic carbon was calculated to be approximately 0.20.

scholarly journals Effect of organic fertilizers on soil organic carbon and risk trace elements content in soil under permanent grassland

2016 ◽  
Vol 10 (No. 4) ◽  
pp. 228-235 ◽  
Author(s):  
H. Karabcová ◽  
L. Pospíšilová ◽  
K. Fiala ◽  
P. Škarpa ◽  
M. Bjelková
Keyword(s):  
Trace Elements ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Organic Fertilizers ◽  
Permanent Grassland
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