scholarly journals Modeling of Permanent Wilting from Particle Size Fractions of Coastal Plain Sands Soils in Southeastern Nigeria

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Chinedu Innocent Obi ◽  
Jude C. Obi ◽  
Emmanuel U. Onweremadu

Permanent wilting points in soils have been found to correlate significantly with particle size fractions. This study was conducted to establish functional relationship between soil particle size fractions and permanent wilting point of soils of coastal plain sands in southeastern Nigeria. A total of 102 surface samples were collected from three different dominantly Ultisols toposequences (i.e., 34 samples from each). Permanent wilting point experiment was carried out in pots with the 102 samples in the greenhouse while the particle size analysis was carried out in the laboratory. There was significant correlation among the textural separates, permanent wilting point correlated significantly with clay (, ). The general linear model showed significant differences between permanent wilting point of soils found in the upper and lower slope positions. Regression equation established that 54% of the total variation in permanent wilting point could be accounted for by the clay and coarse sand content of the soils. Prediction of permanent wilting point of Ultisols formed on coastal plain sands soils of humid tropical southeastern Nigeria will effectively depend on reliability of determination of clay and coarse sand contents of the soils.

Soil Research ◽  
1979 ◽  
Vol 17 (3) ◽  
pp. 383 ◽  
Author(s):  
PH Walker ◽  
J Hutka

Soils and sediments from south-eastern Australia were examined to determine whether texture B horizons had distinctive and unique particle-size characteristics. Most texture B horizons had higher contents of fine clay (<0.2 �m) than coarse clay (0.2-2 �m), whereas coarse clay was the dominant clay-size fraction in A and C horizons. Sequences of soils in alluvium showed a systematic increase in particle-size differentiation with increasing stratigraphic age and corresponding increases in the proportion of fine clay in their B horizons. Pedologically unmodified, clay-rich sediments generally had lower contents of fine clay and higher contents of silt than B horizons. However, sediments of a lake floor and samples of argillans had clay-size fractions similar to B horizons. The distribution of fine clay in soils, determined here by centrifugal sedimentation, was poorly related to illuviated clay determined microscopically. Detailed particle-size data showed that texture B horizons were more enriched than adjacent horizons by a fraction with upper size limits between 0.25 and 0.5 �m. The greater the profile texture contrast, the more pronounced this enrichment became. The enriched clay-size fractions of these B horizons had the particle-size characteristics of log normal distributions. Within the clay-size range of texture B horizons, the fraction < 0.5 �m was the most directly related to surface area measurements made on dry soil samples. Sediments of a lake floor and samples of argillans had similar clay-size characteristics to soil B horizons. It was concluded that particle-size differentiation in these soils was related mainly to pedogenetic processes within the profile. However, the particle-size characteristics of texture B horizons are not unique. Criteria other than those based on particle-size analysis are therefore required to determine the relative importance of translocation and weathering.


Agriculture ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 296
Author(s):  
Siham Zaaboubi ◽  
Lotfi Khiari ◽  
Salah Abdesselam ◽  
Jacques Gallichand ◽  
Fassil Kebede ◽  
...  

For homogeneous fertilization and crop management practices, this work hypothesized that texture could influence cereal yield, particularly in dry regions. Particle size analysis could help improve knowledge of the soil-plant relationship to obtain favorable conditions for better yield. The objective of this work is to develop a single granulometric index for durum wheat (Triticum durum) that is well correlated with yield. For this purpose, 350 independent samples of cereal soils from eastern Algeria were taken and the recorded yields were linked to these samples. The cutoff yield, which separates sub-populations with acceptable yield from those with less acceptable yield, was determined from the inflection point of the cumulative variance ratio functions related to yield by the Richards’ equation. The result obtained is 2.0 Mg.ha−1, with a theoretical critical chi-square value of 4.2, close to 4.6, which is the critical value of r2granulo as obtained by the Cate-Nelson procedure. The five-granulometric indices were found to be symmetrical around zero as follows: ±0.83 for clay (IC), ±1.73 for fine silt (IFL), ±0.31 for coarse silt (ICL), ±0.44 for fine sand (IFS), and ±1.30 for coarse sand (ICS). The two fractions that most influence the textural imbalance are fine silt (IFL) and coarse sand (ICS), with a contribution of 41% and 37%, respectively. The critical single imbalance index r g r a n u l o 2 can be used for determining cereal suitability for soils in the arid region of eastern Algeria. The lower the   r g r a n u l o 2 is, the better the soil for cereal crops.


2012 ◽  
Vol 92 (3) ◽  
pp. 509-519 ◽  
Author(s):  
Y. Yan ◽  
H. He ◽  
X. Zhang ◽  
Y. Chen ◽  
H. Xie ◽  
...  

Yan, Y., He, H., Zhang, X., Chen, Y., Xie, H., Bai, Z., Zhu, P., Ren, J. and Wang, L. 2012. Long-term fertilization effects on carbon and nitrogen in particle-size fractions of a Chinese Mollisol. Can. J. Soil Sci. 92: 509–519. The response of soil organic matter (SOM) dynamics to long-term fertilization may be deduced from changes in the accumulation and distribution of different soil organic carbon (SOC) and nitrogen (N) pools. The SOC and N in particle-size fractions were therefore measured to assess the influences of pig manure and synthetic fertilizer application on the characteristics of these pools. A long-term fertilization experiment, established in 1979 in the Mollisol area (Gongzhuling, China) was used for this study. Composite soil samples (0–20cm) were collected in 2005 from 12 treatment plots that had received annual applications of pig manure, synthetic fertilizers or combinations of both. Soils were fractionated into fine clay (<0.2 µm), coarse clay (0.2–2 µm), silt (2–50 µm), fine sand (50–250 µm) and coarse sand (250–2000 µm) and then SOC and N contents in each particle-size fraction were measured. Although most of the SOC and N were associated with clay and silt fractions, the large proportion of silt in the soil mass played a key role in the retention of SOC and N. The application of pig manure alone increased accumulation of SOC and N in each particle-size fraction, but preferential enrichment was found in the coarse sand fraction. This indicates that pig manure is efficient in restoring SOM in the temperate Chinese Mollisol under a tilled maize (Zea mays L.) monocropping system and having a long frozen period in winter. The application of synthetic fertilizers had no clear effect on SOC and N accumulation or their distribution in particle-size fractions. However, the combined application of pig manure and synthetic fertilizers enhanced the accumulation of SOC and N in all particle-size fractions, and led to a shift of SOC and N from fine to coarse particles. We extended the hierarchy model for SOC protection to consider a shift in SOC accumulation from fine to coarse particles, depending on the initial SOC content of the specific soil. The findings reveal a clear positive interaction between pig manure and synthetic fertilizers that may improve the quantity of SOM in the temperate Chinese Mollisol.


2018 ◽  
Vol 26 (4) ◽  
pp. 352-359
Author(s):  
Julião Soares de Souza Lima ◽  
Samuel Assis Silva ◽  
Daniel Pena Pereira ◽  
Marcelo Soares Altoé

Knowing the variation of particle-size fractions, considering the relief forms, contributes for understanding the variation of other soil attributes. This work aimed to study the spatial distribution of the probability of particle-size fractions occurrence (clay, silt, very fine sand, fine sand, coarse sand, and total sand) in a clayey Oxisol with predominance of concave and convex curvatures. A sampling grid with 94 sampling points in 33x33m spacing at a depth of 0–0.20 m was built using a GPS. The spatial analysis was performed through indicator kriging. The spherical model was fit for all soil fractions, with ranges varying from 130 m to 280 m. In the region of convex curvature, the clay fraction presented the highest probability of occurrence (0.75 to 1.00), whereas in the concave region the coarse sand and total sand fractions presented the highest probability of occurrence. The very fine sand fraction and the silt did not present pattern of distribution in relation to the dominant curvatures of the relief.


Soil Research ◽  
1987 ◽  
Vol 25 (4) ◽  
pp. 347 ◽  
Author(s):  
PJ Thorburn ◽  
RJ Shaw

Particle-size analysis (PSA) methods to be used in routine situations need to be rapid, require no prior information about the sample and give precise results over a wide range of soil textures. Effects of three physical dispersion and two fine-fraction determination methods on PSA results were investigated over a wide range of soil textures to find the most appropriate technique for routine PSA. Interactions between physical dispersion and fine-fraction determination methods were also investigated. The reciprocating shaker produced significantly lower silt and fine sand and higher coarse sand (and clay, although not significant) values than either drink mixer or end-over-end shaker dispersions. This result was interpreted as the reciprocating shaker giving the most effective dispersion, with aggregated clay being dispersed to primary particles while coarse sand was not fragmented to fine sand or silt. The end-over-end shaker did not reliably disperse a heavy clay soil, and so cannot be recommended for routine use where similar soils may be encountered. When considered over all soils and dispersion methods, hydrometer clay and clay + silt values were higher than pipette values. These results were due to the effective depth of the hydrometer being greater, on average, than the depth of the pipette. However, there were interactions between dispersion and fine-fraction determination methods for the clay and clay +silt classes. Hydrometer values were greater than pipette values with drink mixer and end-over-end shaker dispersion, but were similar with reciprocating shaker dispersion. For the clay fraction, inferior dispersion given by the drink mixer and end-over-end shaker resulted in a significant mass of particles between the sampling depths of the pipette and hydrometer, causing the higher hydrometer values. For the clay +silt fraction, both drink mixer and end-over-end dispersion methods fragmented sands to a size which was recorded by the hydrometer but not the pipette. These interactions highlighted the requirement for effective dispersion where clay and silt are determined by the hydrometer, and may explain some of the conflicting observations of the precision of the hydrometer compared with the pipette. Reciprocating shaker physical dispersion combined with the hydrometer fine-fraction determination method was found the most appropriate PSA method combination for use in a routine situation.


2020 ◽  
Vol 13 (1) ◽  
pp. 260-271 ◽  
Author(s):  
Olga A. Samonova ◽  
Elena N. Aseyeva

Partitioning of metals in soil particles of various size classes has been receiving greater significance due to the necessity to predict the behaviour and pathways of the potentially toxic elements in the environment. In this study the analysis of metals’ distribution in various particle size fractions was performed to characterize and compare geochemical features of the topsoil horizons of two small erosional landforms located in uncontaminated area of the central part of European Russia (the Middle Protva basin, mixed forest zone). The landforms represent two typical lithological types of gullies in the study area. Soil samples were fractionated and the concentrations of Fe, Mn, Ti, Zr, Ni, Co, Cr, Zn, Cu, Pb were determined in five particle size fractions: 1–0.25, 0.25-0.05, 0.05−0.01, 0.01–0.001 and <0.001 mm. The metals’ concentrations and their distribution in various particle sizes were found to be related to gully litho-type. The contribution of the clay to the total amount of metals was the greatest for Mn, Zn, Ni and Co in both systems. The highest mass loading for Ti, Zr and Cr came from the coarse silt, while for Cu and Pb it was made by different particle size fractions: the medium and fine silt or the coarse silt. The highest contribution of Fe also came from different fractions, either from the coarse sand or the clay depending on the system.


2020 ◽  
Vol 5 (4) ◽  
pp. 375-398
Author(s):  
Godwin Chinedu Okolo ◽  
Okwudiri Chidubem Emedo ◽  
Adaobi Chinwe Obumselu ◽  
Frances Chizelum Madukwe ◽  
Augustina Ngozi Ulasi

2018 ◽  
Vol 10 (12) ◽  
pp. 126
Author(s):  
Felipe Gomes Frederico da Silveira ◽  
Luciano da Silva Souza ◽  
Laércio Duarte Souza ◽  
João de Mendonça Naime ◽  
Carlos Manoel Pedro Vaz

Soil water retention curve (SWRC) is an important soil attribute because it is a soil quality indicator and is fundamental to study water dynamics in the soil-plant-atmosphere system. Since the conventional SWRC determination is laborious and time-consuming, making it difficult to process a large volume of samples, pedotransfer functions have been used to estimate it by using other soil physical attributes easily determined. Thus, this study aimed to apply Arya-Paris model to SWRC estimation for soils of Bahia state, Brazil, based on soil particle-size analysis, and to compare estimated and determined data of SWRC. Samples were collected from horizons A and AB and/or B and/or C, for a total of 15 soils and 62 horizons. Particle-size was determined by automatic soil particle-size analyzer (PSA) based on g-ray attenuation and traditional Bouyoucos&rsquo; hydrometer (BH) method. Arya-Paris model showed better SWRC predictions for sandy soils, followed by clayey, loamy, and very clayey soils. Good model performance was observed for all soils together. The &alpha; 1 scaling factor provided better predictions, followed by &alpha; 3, and &alpha; 2 showed unsatisfactory behavior. BH method, using only 7 soil particle-size fractions, gave slightly higher predictions than PSA using 30 soil particle-size fractions.


Soil Research ◽  
1990 ◽  
Vol 28 (3) ◽  
pp. 387 ◽  
Author(s):  
JD Armour ◽  
GSP Ritchie ◽  
AD Robson

The zinc (Zn) content of particle size fractions of 12 mainly Zn deficient soils was measured by extraction with three contrasting extractants. The soils, which ranged from sands to a black earth, were from Western Australia and Queensland and particle size fractions (clay, silt, fine sand, coarse sand) were obtained by sieving and sedimentation after ultrasonification of soil suspended in deionized water. The extractants were concentrated HNO3/H2SO4/HClO4 (acid extractable or AE-Zn), DTPA and 0.002 M CaCl2. For each extractant, Zn contents of the fractions and whole soils were correlated with organic carbon and ammonium oxalate extractable Fe and Al. The AE-Zn concentrations in whole soils were 0.6-132 mg kg-1 and high clay soils had higher concentrations (mean 54 mg kg-1) than low clay soils (mean 2 mg kg-1). After fractionation, lowest AE- and DTPA-Zn were found in coarse sand fractions and concentrations increased with decreasing particle size. Clay plus silt fractions contained 60-99% of the whole soil AE-Zn and 76-93% of the whole soil DTPA-Zn. The CaCl2-Zn concentrations were very low (<5.0 �g kg-1) for all soils. In whole soils, DTPA-Zn was only a small proportion, 3.2% and 1.8%, of the AE-Zn in the low clay and high clay soils, respectively. The CaCl2-Zn was generally less than 2% of the DTPA-Zn in whole soils. In whole soils, AE-Zn was correlated with oxalate extractable Fe and with oxalate A1 (r = 0.72 and 0.71, respectively; P <0.01), whereas DTPA-Zn was correlated with oxalate extractable Fe (r = 0.82; P < 0.01). The AE- and DTPA-Zn were correlated with organic carbon only in some fractions. The DTPA- and CaCl2-Zn were not correlated with AE-Zn content, nor was DPTA-Zn correlated with CaCl2-Zn in whole soils or fractions (P<0.05). Dispersion of the soils with ultrasonification in the absence of dispersing agents was not as effective as dispersion with conventional mechanical/chemical dispersion. The percentage of the soil recovered in the clay fraction after sonification was 23-78% of that recovered by the conventional method. Fine and coarse sand contents were similar for either method, indicating that incomplete dispersion of clay by ultrasonification resulted in higher silt contents.


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