Characteristics and genesis of two strongly weathered soils in Samar, Philippines

Soil Research ◽  
2007 ◽  
Vol 45 (3) ◽  
pp. 153 ◽  
Author(s):  
Ian A. Navarrete ◽  
Victor B. Asio ◽  
Reinhold Jahn ◽  
Kiyoshi Tsutsuki

Very limited data have been published on the nature of strongly weathered soils in geologically young humid tropical islands. The study evaluated the characteristics and formation of 2 strongly weathered soils in the island of Samar, Philippines, one developed from slate (Bagacay soil) and the other from ultrabasic rock (Salcedo soil). Results revealed that the soils have generally similar morphological characteristics, particularly in terms of colour (2.5 YR-10 R), solum thickness (>5.0 m), and structure (granular to subangular blocky), although the Salcedo soil has much higher clay content than the Bagacay soil. Both soils have similar chemical properties (e.g. acidic, low exchangeable bases) except that the Salcedo soil has lower CEC values but higher exchangeable Na content, resulting in a higher base saturation. They also have high dithionite-extractable Fe contents and very low oxalate/dithionite ratios and are dominated by halloysite, kaolinite, gibbsite, goethite, hematite, and quartz in the clay fraction. Apparently as a result of its more weatherable ultrabasic parent rock and more stable geomorphic surface, the Salcedo soil shows more advanced weathering and soil development than the Bagacay soil. Salcedo soil is classified as Haplic Ferralsol (Dystric, Clayic, Rhodic) in the World Reference Base or very fine, sesquic, isohyperthermic, Rhodic Hapludox in the Soil Taxonomy. Bagacay soil is a Haplic Acrisol (Alumic, Hyperdystric, Clayic, Rhodic) or fine, kaolinitic, isohyperthermic, Typic Paleudult. The Salcedo soil has very high Ni and Cr contents inherited from its ultrabasic parent material. The study reveals that on the geologically young humid tropical island of Samar, the characteristics and genesis of strongly weathered soils are greatly affected by the geochemical characteristic of the parent rock material.

1997 ◽  
Vol 77 (2) ◽  
pp. 295-307 ◽  
Author(s):  
T. A. Okusami ◽  
R. H. Rust ◽  
A. O. Alao

Representative profiles of the Owena, Egbeda, Alagba, and Balogun series were studied. The Owena soil is formed in amphibolite whereas Egbeda and Balogun soils are formed in biotite gneiss derived parent materials. The Alagba soil is formed in sandstone parent rock. The main objectives were to characterize the soils and their clay fraction, and to classify and interpret soil properties for agricultural land use. Most soils exhibit 2.5 YR hues in subsurface horizons. A pedon formed in biotite gneiss has the highest dithionite Fe content and Fed/clay ratio. The relationships between clay content and Fed values vary according to parent material origin and, therefore, would have to be interpreted differently for soil weathering processes. Clay coatings were noticeable in some soil horizons of all pedons studied. Soils are generally medium to slightly acid with sandstone-derived soils being the most acid. The clay mineral suite in all soils is dominated by kaolinite with traces of 2:1 and 2:2 clay minerals, goethite, hematite, anatase, maghemite, and rutile. In addition, some soils contain trace amounts of gibbsite. Kandic horizons have been identified in all soils. The low charge properties of the soils reflect the intensely weathered clay mineral suite. The base status is probably influenced by the cropping system and therefore may tend to unnecessarily differentiate highly weathered soils at the order level. The Egbeda and Balogun series were classified as Rhodic Kandiudults, clayey-skeletal, oxidic and Rhodic Kandiudalfs, clayey-skeletal, oxidic, respectively. Others, Owena, and Alagba series, were classified as Typic Kanhaplohumults, clayey, oxidic and Rhodic Kanhaplustults, fine loamy or clayey, oxidic, respectively. In the FAO-Unesco legend, all soils become Rhodic Ferralsols. In addition, the Owena (with its nitic properties) is further classified as niti-rhodic Ferralsol. The two classification systems are at variance for highly weathered (variable charge property) soils and this difference will definitely influence management decisions depending on which system is used at any particular time. Soil attributes favorable for agricultural use include thick sola and favorable structures. Chemical properties suggest minimal fixation of phosphorus. Key words: Dithionite Fe, kandic, oxidic, variable charge, ferralic, exchangeable Al


2018 ◽  
pp. 72-80
Author(s):  
Osujieke D.N ◽  
Obasi N.S. ◽  
Imadojemu P.E ◽  
Ekawa M. ◽  
Angyu M.D.

The study was aimed at the characterizing and the classifying of soils of Jalingo metropo- lis in Taraba State, North-East Nigeria. Profile pit was dug on each of the three different sites of the study area as identified using free survey. The profile pits were described and sampled bases on horizon differentiation for laboratory analyses. A total of 10 samples were collected. Data generated were analyzed using descriptive statistics to determine their coefficient of variation. The result indicated that the horizons were mostly reddish when moist at different contrasting level. The textural classes were mostly loamy sand while the sub-angular blocky structure was observed in the entire subsurface horizons. The horizons of the pedons were well drained. Sand fraction had means of 826.80 g/kg, 816.80 g/kg and 766.8 g/kg for pedons 1, 2, and 3 respectively. Clay fraction increased in an in- creasing soil depth which formed an argillic horizon. Sand fraction, bulk density and parti- cle density recorded low variation (≥0 % ≤5.22 %) in among the pedons. Soil pH(H2O) had a mean of 6.40 in pedon 1, 6.43 in pedon 2 and 6.41 in pedon 3. Organic carbon ranged from ≥2.0 g/kg ≤0.43 g/kg while cation exchange capacity ranged from ≥4.58 cmol/kg ≤5.01 cmol/kg among the pedons. The percent base saturation had a mean of 66.6 %, 65.1 % and 66 % in pedon 1, 2 and 3. Hence, pedons 1 and 2 were classified as Grossarenic Kandiustalfs (Arenic Lixisols), while pedon 3 was classified as Arenic Kandi- ustalfs (Loamic Lixisols) according to USDA soil taxonomy and correlated with world reference base.


2019 ◽  
pp. 74-86

Twelve profile pits were sunk, four in each of the three locations of Bukuru, the study area. Proper soil profile description was done and recorded to obtain field characterization data after which thirty-six soil samples were collected from all the genetic horizons for soil characterization. Bukuru soils showed higher sand fraction (71%) than silt (12%) and clay (17%) at the topsoil but showed increased clay content at the subsoil. While Gyel and Fwarti locations soils were sandy loam, Rabi location soil was sandy clay loam. Soil pH, Organic carbon (Org. C), Total Nitrogen (Total N), and Available phosphorus (Avail. P) were 6.2, 6.3 gkg- 1, 1.9 gkg-1 and 4.82 mgkg-1respectively and were graded low. Exchangeable bases were dominated by Ca2+ and Mg2+. Sodium (Na+), Potassium (K+), Cal- cium (Ca) and Magnesium (Mg) were 0.24 cmolkg-1, 0.06 cmolkg-1, 15.7 cmolkg-1 and 2.60 cmolkg-1 respectively. While Na+ and K+ were graded low, Ca2+ and Mg2+ were graded high. Cation Exchange Capacity (CEC) was 18.82 cmolkg-1, and was graded high. All the soil samples analysed showed high per- centage base saturation (PBS), above 90%. The low values of Org. C, Total N, Na and K and the characteristic sandiness of Bukuru soils in the surface horizon indicated the low fertility status of Bukuru soils. Bukuru soils were classified using the Keys to Soil taxonomy of the USDA as “Typic isothermic kandic us- talfs”. This was correlated to “Lixisols” in the World Reference Base (WRB) of FAO at a higher level and "Rhodic/Chromic" as a principal qualifier. .


2021 ◽  
Vol 5 (1) ◽  
pp. 47-57
Author(s):  
Chike Onyeke Madueke ◽  
Ikokwu Kalu Okore ◽  
Ebubechukwu Chizoba Maduekeh ◽  
Akudo Ogechukwu Onunwa ◽  
Maduabuchi Johnbosco Okafor ◽  
...  

Data on the nature, properties and potentials of soils is grossly inadequate in the rainforest belt of southeastern Nigeria. As such, policymakers and other land users have tended to subscribe to unduly generalized ideas about the soils of the region. This has led to improper land use planning and aggravated land degradation. This necessitated the need for the comparative evaluation of the nature and potentials of the soils of the region to determine their degree of variability. Profile pits were dug in four towns underlain by different geologic formations: Umungwa (Benin Formation), Umuawa Ogii (Nsukka Formation), Ikpem (Igbaku Sandstones) and Amuro (Imo Clay Shales). The soils were characterized and classified using the World Reference Base for Soil Resources (WRB), United States Department of Agriculture (USDA) Soil Taxonomy and land capability classification. The variability of soils across the different sites was subsequently analysed using the coefficient of variation (CV). The results show that the variability of sand across the study sites was moderate (20 – 21 %), silt was high (63 %), clay ranged from moderate (34 %) to high (52 %), while hydraulic conductivity was very high (128 – 144 %). Similarly, with regards to the chemical properties, soil pH and base saturation ranged from moderate (20 – 49 %) to high (52 %), while effective cation exchange capacity (ECEC) and aluminium saturation were high (70 – 77 %). It was concluded that the soils of southeastern Nigeria are very heterogeneous. Undue generalization should consequently be discouraged.


2010 ◽  
Vol 59 (1) ◽  
pp. 93-98 ◽  
Author(s):  
M. Fuchs ◽  
A. Gál ◽  
E. Michéli

The soil cover of the world stores more carbon than that present in biomass and in the atmosphere, so the depth and distribution of soil organic matter (SOM) might be important in point of carbon sequestration and climate change mitigation. Texture, among several other factors, plays an important role in the distribution of SOM. Most national and the main international soil classification systems (Soil Taxonomy, World Reference Base for Soil Resources) have a separate unit for high clay content soils on the highest level of classification, as Vertisols. Due to the high swelling clay content, these soils open deep cracks when they are dry. During the process called “pedoturbation”, the high SOM content surface material falls into the cracks, where it accumulates and mixes with subsoil, and enhances the accumulation of SOM in great depth. Although the effect of texture on the stabilization, distribution and properties of SOM have been investigated, only little information is available on SOM distribution in high clay content soils. The objective of the present study was to analyze the vertical distribution of SOM in high clay content soils of Hungary. Our results, based on the investigations of the Hungarian TIM database supported the hypothesis that high clay content soils store significantly more SOM and in greater depth than other soils under similar climatic conditions.


2018 ◽  
Vol 111 (1) ◽  
pp. 121 ◽  
Author(s):  
Rok TURNIŠKI ◽  
Helena GRČMAN

Eluvial-illuvial processes plays key role in pedogenesis, especially in the development of leached soils. As reported in Slovenian soil map 1 : 25.000 leached soils cover 2,3 % of Slovenian territory. They occur on different parent materials, mostly on flat relief preserved from erosion and colluvial processes. The aim of our study is the evaluation of their morpohological, physical and chemical properties, spatial distribution and dependency on soil forming factors, especially on parent material. Pedological properties are demonstrated according to analytical and descriptive data of 49 leached soils from the pedological base of Soil Information System of Slovenia. Obvious leaching processes are clearly recognized in almost all profiles of leached soils. Eluvial horizon in comparison to illuvial horizon has lower pH value, which is in average 4,4 and 4,6 for E and Bt horizon respectively, brighter color, lower base saturation (in average for 16,6 %) and lower CEC (in average for 5,5 mmol<sub>c</sub> 100 g <sup>-1</sup> soil). On average ratio of clay content between illuvial and eluvial horizon is 1,63. In the 75 % of all studied leached soils this ratio is above 1,38. After evaluation, according to WRB classification, an argic horizon is identified only in 40 soil profiles, while other 9 profiles do not match criteria of sufficient textural differentiation or there is not enough data to classify them. Detailed overview of the WRB criteria for argic horizons (cation exchange capacity of clay fraction and base saturation in argic horizons) reveals that Luvisols and Alisols are the most widespread groups in Slovenia among leached soil. Against expectations based on different references, we do not determined Acrisols within Soil Map Database.


Agro-Science ◽  
2021 ◽  
Vol 20 (3) ◽  
pp. 14-23
Author(s):  
O.N. Ajala ◽  
T.A. Adjadeh ◽  
J.O. Olaniyan ◽  
T.O. Isimikalu ◽  
E.K. Nartey ◽  
...  

A reconnaissance survey conducted at the University of Ilorin Sugar Research Farm (USRF) revealed four dominant soils at Site 1 (USRF1) and one at Site 2 (USRF2). The soils were characterized and classified according to both the Soil Taxonomy (ST) and the World Reference Base for Soil Resources (WRB). Also, the suitability of the soils for sugarcane cultivation was evaluated using the limitation approach. While the USRF1 soils were reddish, the USRF2 soil was greyish due to poor drainage. The USRF1 soils were loamy sand with the AB-horizons of pedons II and III being gravelly. Pedon V had sandy loam surface, sandy clay loam subsurface and clay loam subsoil. The USRF1 soils were moderately acid while the USRF2 soil was slightly acid to slightly alkaline. Exchangeable calcium (Ca2+) content of the USRF2 soil which averaged 4.00 cmolc kg–1 was 2-3 times higher than that of the USRF1 soils. The USRF2 soil also contained higher Mg2+, K+ and Na+, 2-3 folds higher effective cation exchange capacity and > 10 folds higher soil organic carbon (with mean of 11.60 g kg–1) and total nitrogen (mean of 0.94 g kg–1). Under ST, pedons I and IV classified as Typic Haplustepts, II and III as Lithic Haplustepts and V as a Kanhaplic Haplustalf. Under WRB, pedons I and IV classified as Eutric Regosols (arenic), II and III as Endo-pisoplinthic Cambisols (arenic) and V as a Gleyic Lixisol (loamic). Pedon V was highly suitable (85.25%), I and IV moderately suitable (64.53%), II marginally suitable (47.40%) and III unsuitable (35.62%) for sugarcane cultivation.


Agro-Science ◽  
2020 ◽  
Vol 19 (3) ◽  
pp. 51-61
Author(s):  
F.C. Okenmuo ◽  
C.O. Anochie ◽  
M.E. Ukabiala ◽  
C.L.A. Asadu ◽  
P.K. Kefas ◽  
...  

The soils of Atani floodplain in Anambra State of Nigeria contribute significantly to the food production of the State, hence the need to understand their behavior in order to enhance their management and productivity. Profile pits were sited along three physiographic units viz: levee crest, levee  slope and flood basin. Soil samples were collected from the profile horizons and subjected to standard laboratory procedures. Characterization of the soils was based on their morphological, physical and chemical properties. Soil classification was carried out using the USDA Soil Taxonomy and correlated with FAO/IUSS World Reference Base. Its agricultural potential was assessed using the fertility capability classification. The soils were deep. Topsoil colour was dominantly blackish black (10YR 3/2). Mottles were pervasive; an indication of impeded drainage conditions. The soils were predominantly fine textured. Soil pH values ranged from 4.8 to 6.2. Exchangeable Calcium was low to moderate (2.6-8.2 cmol kg−1); Magnesium was moderate to high (1.6-6.8 cmol kg−1); Sodium was high to very high (1.0-2.5 cmol kg−1), while potassium was high (1.2-4.2 cmol kg−1). Cation  exchange capacity values ranged from 11.6 to 42.6 cmol kg−1. Total nitrogen was very low to low (0.14-1.12 g kg−1), while organic carbon was low to moderate (0.4-15.2 g kg−1). Available phosphorus was very low to high ranging from 0.93 to 31.71 mg kg−1 while base saturation ranged from 64 to 93%. The soils were classified as Typic Fluvaquents (Typic Fluvisols), Fluvaquentic Endoaquepts (Endostagnic Cambisols) and Fluventic Endoaquepts (Endostagnic Cambisols) according to the USDA and FAO/IUSS. The fertility capability evaluation of the soils revealed that the pedons were Lgn in classification due to limitations in drainage. Key words: alluvium, cambic horizon, Inceptisols, lithologic discontinuity


2014 ◽  
Vol 9 (No. 4) ◽  
pp. 153-160 ◽  
Author(s):  
A. Žigová ◽  
M. Šťastný

The development of soil cover on volcanic rocks in Central and North Bohemia was analyzed. The study was performed in the protected landscape areas on basalt, andesite, and dolerite. Parent material was characterized on the basis of thin-section study. Petrography of the parent material makes it possible to document the differences in the texture, character, and amount of rock-forming minerals. All the studied sequences exhibit the same configuration of soil profiles but various thicknesses. The soil profiles were evaluated on the basis of particle size distribution, chemical properties, soil organic matter parameters, and mineral composition of clay fraction. The major specific pedogenic process in soils developed on volcanic rocks is weathering of parent material and development of the Bw horizon with the formation of mainly smectite from the group of swelling clay minerals. The results revealed differences in the formation of the Bw horizon which is significantly affected by the petrography of the parent material and local geological conditions. According to the type of volcanic rocks, the intensity of the developmental process of the Bw horizon is as follows: andesite (T&yacute;řovick&eacute; sk&aacute;ly) &gt; dolerite (Z&aacute;hrabsk&aacute;) &gt; basalt (Březina).


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