scholarly journals Earthworm Community In Relation To Soil Properties And Metals In Hebei Province, North China

Author(s):  
Yue Yin ◽  
Kun Wang ◽  
Miaomiao Chen ◽  
Xiaoquan Mu ◽  
Bo Li ◽  
...  

Abstract In this study, we examined the influence of soil properties (pH, total potassium (TK), available potassium (AK), total nitrogen (TN), total phosphorus (TP), available potassium (AP), cation exchange capacity (CEC), and soil organic carbon (SOC)), and metals (Cd, Pb, Cu, and Zn) on the density, diversity, and species composition of earthworms in the Hebei Province, North China. In total, 535 earthworms were collected from 20 sites in the study area, and belonged to three families, six genera, and ten species. Amynthas hupeiensis (39.4%) and Drawida gisti (37.8%) were the dominant species. The correlations between soil variables and earthworm composition determined using redundancy analysis indicated that SOC, TK, and AK enhanced earthworm density (total, adult, and juvenile) and species (A. hupeiensis and D. gisti) abundances. Earthworm composition remained unaffected by the metals (Cd and Pb) in the uncontaminated sites; in contrast, species were absent in areas with high metal concentrations (S19 and S20). Soil TN content was negatively and positively related to Shannon and Peilou indexes (p<0.05), respectively, indicating that TN may be pivotal in influencing earthworm diversity and species evenness. Overall, the soil properties such as K, SOC, and TN were the key variables affecting earthworm density, diversity, and species dominance.

CORD ◽  
1988 ◽  
Vol 4 (01) ◽  
pp. 34
Author(s):  
Doah Dekok Tarigans

This study was conducted to investigate the effects of six co­conut cropping patterns on the soil properties and nutrient element status of coconut leaves. The experiments were carried out from August 1984 to May 1985 in Silang, Cavite, Philippines. Data on‑soil properties and nutrient element starus of coconut leaves were statistically analyzed in Randomized Block Design with three replications. Six cropping patterns in coconut with four species of perennial crops as intercrops, namely: banana, papaya, coffee and pineapple were used in this study. The organic matter, pH and cation exchange capacity of the soils did not differ significantly with cropping pattern although intensively cropped farms tended to have higher organic matter' and cation exchange capacity values. Nitrogen, phosphorus and potassium in the top soil were significantly higher in most intensive intercropped farms, but calcium and magnesium did not vary significantly. Moisture content, waterholding capacity, bulk density and particle density of the soil did not show significant difference with cropping patterns. Likewise, the number of bacteria, fungi and actinomycetes in the soil remained statistically the same. Leaf nitrogen and calcium, in­creased while potassium decreased with intensity of cropping. Phosphorus and magnesium showed no definite trend.


Soil Research ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 1253 ◽  
Author(s):  
D. Singh ◽  
R. G. McLaren ◽  
K. C. Cameron

Compared with zinc (Zn) sorption, there is very little information on the effect of soil properties on Zn desorption from soils. In this study, desorption of native and added Zn from 7 Canterbury (NZ) soils was determined using a technique involving repeated equilibration of soil in 0·01 M Ca(NO3)2. The concentrations and patterns of desorption of both native and added Zn varied between the different soils. Greater concentrations of native Zn were desorbed from surface soils than from subsoils, and greater concentrations of added Zn were desorbed from subsoils than from their corresponding surface horizons. Correlation analysis showed that cation exchange capacity (CEC) and organic carbon (C) were the dominant soil variables contributing towards sorption or desorption of Zn. However, simple linear regressions involving CEC or organic C explained only 48–62% of the total variation in Zn sorption or desorption from the different soils. Multiple regression analysis indicated that cumulative native Zn desorption (expressed as percentage of DTPA-extractable Zn) was strongly related to CEC and the content of Mn oxides, which in combination explained 80% of the variability between soils. Regression analysis also showed that CEC plus Mn oxides and pH explained 91% of the variability in Zn sorption between the soils; whereas for added Zn desorbed (%), CEC plus pH and crystalline Al oxides explained 93% of variability in added Zn desorption.


2013 ◽  
Vol 27 (1) ◽  
pp. 57-67 ◽  
Author(s):  
S.E. Obalum ◽  
J. Oppong ◽  
C.A. Igwe ◽  
Y. Watanabe ◽  
M.E. Obi

Abstract The spatial variability of some physicochemical properties of topsoils/subsoils under secondary forest, grassland fallow, and bare-soil fallow of three locations was evaluated. The data were analyzed and described using classical statistical parameters. Based on the coefficient of variation, bulk density, total porosity, 60-cm-tension moisture content, and soil pH were of low variability. Coarse and fine sand were of moderate variability. Highly variable soil properties included silt, clay, macroporosity, saturated hydraulic conductivity, organic matter concentration, and cation exchange capacity. Overall, soil pH and silt varied the least and the most, respectively. Relative weighting showed that location dominantly influenced the soil variability, except for soil porosity and organic matter concentration influenced mostly by land use. Most of the soil data were normally distributed; others were positively skewed and/or kurtotic. The minimum number of samples (at 25 samples ha-1) required to estimate mean values of soil properties was highly soil property-specific, ranging from 1 (topsoil pH-H2O) to 246 (topsoil silt). Cation exchange capacity of subsoils related fairly strongly with cation exchange capacity of topsoils (R2 = 0.63). Spatial variability data can be used to extrapolate dynamic soil properties across a derived-savanna landscape.


Solid Earth ◽  
2017 ◽  
Vol 8 (4) ◽  
pp. 827-843 ◽  
Author(s):  
Sunday Adenrele Adeniyi ◽  
Willem Petrus de Clercq ◽  
Adriaan van Niekerk

Abstract. Cocoa agroecosystems are a major land-use type in the tropical rainforest belt of West Africa, reportedly associated with several ecological changes, including soil degradation. This study aims to develop a composite soil degradation assessment index (CSDI) for determining the degradation level of cocoa soils under smallholder agroecosystems of southwestern Nigeria. Plots where natural forests have been converted to cocoa agroecosystems of ages 1–10, 11–40, and 41–80 years, respectively representing young cocoa plantations (YCPs), mature cocoa plantations (MCPs), and senescent cocoa plantations (SCPs), were identified to represent the biological cycle of the cocoa tree. Soil samples were collected at a depth of 0 to 20 cm in each plot and analysed in terms of their physical, chemical, and biological properties. Factor analysis of soil data revealed four major interacting soil degradation processes: decline in soil nutrients, loss of soil organic matter, increase in soil acidity, and the breakdown of soil textural characteristics over time. These processes were represented by eight soil properties (extractable zinc, silt, soil organic matter (SOM), cation exchange capacity (CEC), available phosphorus, total porosity, pH, and clay content). These soil properties were subjected to forward stepwise discriminant analysis (STEPDA), and the result showed that four soil properties (extractable zinc, cation exchange capacity, SOM, and clay content) are the most useful in separating the studied soils into YCP, MCP, and SCP. In this way, we have sufficiently eliminated redundancy in the final selection of soil degradation indicators. Based on these four soil parameters, a CSDI was developed and used to classify selected cocoa soils into three different classes of degradation. The results revealed that 65 % of the selected cocoa farms are moderately degraded, while 18 % have a high degradation status. The numerical value of the CSDI as an objective index of soil degradation under cocoa agroecosystems was statistically validated. The results of this study reveal that soil management should promote activities that help to increase organic matter and reduce Zn deficiency over the cocoa growth cycle. Finally, the newly developed CSDI can provide an early warning of soil degradation processes and help farmers and extension officers to implement rehabilitation practices on degraded cocoa soils.


1974 ◽  
Vol 54 (2) ◽  
pp. 195-204 ◽  
Author(s):  
B. KLOOSTERMAN ◽  
L. M. LAVKULICH ◽  
M. K. JOHN

The potential application of a computer soil data file to the study of soil concepts is discussed. This method aids the pedologist to analyze, summarize and correlate large quantities of data. For applied objectives the data file allows the prediction of soil properties for interpretive purposes. The computerized soil data file was used to explore its usefulness in studying the concept of the modal profile, confirmation of definitions of the Podzolic and Gleysolic Great Groups, derivation of equations for estimating soil drainage and cation-exchange capacity, and studying some interrelationships among soil properties. Soil parameters used to define soils at the Order and Great Group levels did trend toward normal distributions for Gleysolic but less for Podzolic soils. The prediction equations for cation-exchange capacity accounted for a higher percentage of the variation than did equations for soil drainage. Many soil property interrelationships were confirmed. The study illustrates some of the weaknesses of using routine soil survey data collected over a 10-yr period.


2014 ◽  
Vol 472 ◽  
pp. 926-934 ◽  
Author(s):  
Z. Nahrul Hayawin ◽  
A.A. Astimar ◽  
R. Ridzuan ◽  
Z. Bidattul Syirat ◽  
N. Ravi Menon ◽  
...  

This research work deals with the production of vermicompost from empty fruit bunch (EFB) blended with cow dung using an epigeic earthworm known as Eudrilus Eugeniae. The vermicomposting mixture was carried out in a humid environment with moisture content between 70% to 80% and a pH of between 6 to 8. Natural zeolite, such as clinoptilolite and charcoal were mixed with vermicompost at different ratios and prior to being pelletized. The highest cation exchange capacity (CEC) was observed at 10% of zeolite (Z2) and 20% of charcoal (C4) mixtures. The proportion of 10% zeolite in the mixture resulted in the highest of Cu reduction by 44% and manganese by 60% and in addition the 15% charcoal caused the highest reduction of iron (Fe) by 32%. A significant decrease in carbon to nitrogen C/N ratio and an overall increase in total nitrogen, total available phosporous and total potassium were also discussed in this paper.


2017 ◽  
Vol 54 (5) ◽  
pp. 794-804
Author(s):  
BERNARD DUBOS ◽  
VICTOR BARON ◽  
XAVIER BONNEAU ◽  
ALBERT FLORI ◽  
JEAN OLLIVIER

SUMMARYPotassium chloride (KCl) is the most widely used fertilizer in oil palm (Elaeis guineensis) plantations and the rates applied are based on interpretation of leaf K contents. When no positive response on leaf K contents can be detected, no optimum content can be established whatever the yield response to KCl rates. We used data from 13 fertilization trials conducted on several continents to study the responses of leaf K, leaf Cl, leaf Ca and yield to KCl rates as a function of the soil properties of each site. We found that the abundance of exchangeable Ca in the soil expressed as a percent of the cation exchange capacity (CEC) was the best soil variable to predict if leaf K content would increase with KCl rates. In addition, we found that the leaf K contents of unfertilized controls at the end of the trials were also correlated with Ca/CEC. This ratio thus appears to be a better index of soil K reserves than soil exchangeable K content.


Soil Research ◽  
2018 ◽  
Vol 56 (4) ◽  
pp. 421 ◽  
Author(s):  
M. Shahadat Hossain ◽  
G. K. M. Mustafizur Rahman ◽  
M. Saiful Alam ◽  
M. Mizanur Rahman ◽  
A. R. M. Solaiman ◽  
...  

Soil texture is an independent and innate soil property and other dynamic soil properties such as electrical conductivity (EC), organic carbon (OC) content and cation exchange capacity (CEC) are mostly dependent on it. An attempt was made to develop a model for numerically simulating soil texture and also to construct relationships of the developed model with other soil properties. Hypothetical data of particle size distribution and our data were used to justify and validate the newly defined indices. Scatter diagrams showed good association between the indices and hypothetical data of soil separates. Moreover, similar trends were observed between the line charts of USDA soil textural class codes and the indices. Strong correlations (r = 0.78–0.96) were found between the indices and soil separates (sand, silt and clay) for our data. However, the indices demonstrated moderate correlations (r = –0.34 to –0.55) with EC and OC of the soils. Strong nonlinear relationships were found between CEC and the three indices (R2 = 0.699, R2 = 0.732 and R2 = 0.672 (all P < 0.001). Furthermore, the variability of EC, OC and CEC within a single USDA textural class and customised textural index groups were described using the developed model. The developed indices showed excellent fitness for simulation of soil texture and demonstrated an extended applicability in terms of their relationships with soil properties related to soil texture, which will help in constructing digital soil maps.


1982 ◽  
Vol 62 (4) ◽  
pp. 657-662 ◽  
Author(s):  
C. WANG

The results of a study which compared some selected soil characteristics of small and large map unit delineations are presented. Color, organic carbon, pH, cation exchange capacity and clay content were measured. Properties, such as pH and CEC of surface soil and pH of subsoil, were found to be significantly different between large and small delineations. Although Brandon is selected to be a simple and relatively uniform map unit, the range of variation was wide for all of the selected soil properties. For each property measured the coefficient of variability was always larger in surface soils than in subsoils. However, variance of measured soil properties did not differ between the two groups of delineations. Consequently, the soil boundary effect is considered to be insignificant for the Brandon unit of the Dalhousie association studied.


Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3936 ◽  
Author(s):  
Tibet Khongnawang ◽  
Ehsan Zare ◽  
Dongxue Zhao ◽  
Pranee Srihabun ◽  
John Triantafilis

Most cultivated upland areas of northeast Thailand are characterized by sandy and infertile soils, which are difficult to improve agriculturally. Information about the clay (%) and cation exchange capacity (CEC—cmol(+)/kg) are required. Because it is expensive to analyse these soil properties, electromagnetic (EM) induction instruments are increasingly being used. This is because the measured apparent soil electrical conductivity (ECa—mS/m), can often be correlated directly with measured topsoil (0–0.3 m), subsurface (0.3–0.6 m) and subsoil (0.6–0.9 m) clay and CEC. In this study, we explore the potential to use this approach and considering a linear regression (LR) between EM38 acquired ECa in horizontal (ECah) and vertical (ECav) modes of operation and the soil properties at each of these depths. We compare this approach with a universal LR relationship developed between calculated true electrical conductivity (σ—mS/m) and laboratory measured clay and CEC at various depths. We estimate σ by inverting ECah and ECav data, using a quasi-3D inversion algorithm (EM4Soil). The best LR between ECa and soil properties was between ECah and subsoil clay (R2 = 0.43) and subsoil CEC (R2 = 0.56). We concluded these LR were unsatisfactory to predict clay or CEC at any of the three depths, however. In comparison, we found that a universal LR could be established between σ with clay (R2 = 0.65) and CEC (R2 = 0.68). The LR model validation was tested using a leave-one-out-cross-validation. The results indicated that the universal LR between σ and clay at any depth was precise (RMSE = 2.17), unbiased (ME = 0.27) with good concordance (Lin’s = 0.78). Similarly, satisfactory results were obtained by the LR between σ and CEC (Lin’s = 0.80). We conclude that in a field where a direct LR relationship between clay or CEC and ECa cannot be established, can still potentially be mapped by developing a LR between estimates of σ with clay or CEC if they all vary with depth.


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