scholarly journals COMPARATIVE ASSESSMENT OF TROPICAL RAINFOREST SOILS FORMED FROM DIFFERENT GEOLOGIC FORMATIONS IN SOUTHEASTERN NIGERIA

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.

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


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.


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.


2020 ◽  
pp. 111-123

The slope orientation and position of toposequence influence soil properties along the landscape. The study classified and evaluated the fertility status of soils on slopes of varying orientations in Umudike (East-lying Toposequence) and Itu (West-lying Toposequence) located in Olokoro Umuahia, Abia State southeastern Nigeria. Transect soil sampling technique was employed in locating 3 distinct top units (Summit, Midslope and Footslope) along each of the toposequence. Soil profile pit was dug at each top unit, described using FAO guidelines and sampled according to genetic horizons. Soil samples collected were subjected to routine laboratory analyses. Pedons were classified using the USDA Soil Taxonomy System and correlated with World Reference Base while the fertility status was evaluated using elemental ratios. The results indicated that soils of the two toposequence were dominated by sandy clay loam texture. Consistency of the pedons generally varied from very friable (Vfr) to very firm (Vfi) in the two toposequence. Soil pH was very strongly acidic (4.58-4.78) in the east lying toposequence but varied from very strongly acidic to strongly acidic (4.52-5.30) in the west lying toposequence. Organic matter concentration was higher at the epipedons and ranged from 26.44 to 23.36 g kg -1 and 18.9 to 30.64 g kg -1 in soils of east-lying and west-lying slopes, respectively. K: Mg ratio varied from 0.01- 0.12 and 0.01-0.08 at the east and west lying slopes, respectively. The pedons of the summit, midslope and footslope were as classified Grossarenic Paleudalfs, Typic Paleudalfs and Arenic Hapludalfs for respectively for the east-lying slope and Arenic Glossudalfs, Typic Paleudalfs and Typic Ferrudalfs, respectively for the west-lying slope. Generally, the two toposequences were of poor fertility status.


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. .


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.


Author(s):  
C. V. Ogbenna ◽  
V. E. Osodeke

Aim: A pot experiment was carried out to determine the effect of sawdust ash and lime (Ca(OH)2) on soil characteristics and yield of sunflower in acidic soil of southeastern Nigeria. Study Design: The experiment was laid out in split-plot design, using sawdust ash (0, 1, 2, 3, 4 t ha-1) as the sub plot and lime (0, 0.5, 1.0, 1.5 t ha-1) as the main plot. Place and Duration of Study: Study was conducted outdoors at Michael Okpara University of Agriculture Umudike, Nigeria, during the 2010 planting season. Materials and Methods: Treatment combinations were applied to the 60 buckets containing soil, mixed thoroughly and watered adequately. After 1 week of treatment application, two sunflower seeds were planted and later thinned to one seedling per bucket. Plant growth and yield data were collected. Pre planting and post-harvest soil samples were collected and analyzed for soil properties. Results: Results showed that with the exception of organic carbon there was significant effect of treatments on all soil chemical properties. Lime and sawdust ash (SDA) as single and combined treatments significantly increased total nitrogen (P=0.05), available phosphorus (P<0.010), and base saturation (P<0.012). The interaction between SDA and lime significantly (P=0.05) increased total exchangeable bases and effective cation exchange capacity, while soil pH was significantly increased (P=0.05) by single applications. The increases in soil chemical properties led to significant positive response of the sunflower. With the exception of number of leaves, other plant parameters (Plant height, stem diameter, head weight, 50 seed weight, head diameter) had significant increases for sawdust ash alone at P=0.05. Correlation studies showed positive significant relationship between soil pH and sunflower yield. Conclusion: The study showed that sunflower performed best at the combination of 3 tha-1 SDA and 1.5 t ha-1 lime producing a mean head weight of 45.4 g.


Land ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 154 ◽  
Author(s):  
Orestis Kairis ◽  
Vassiliki Dimitriou ◽  
Chrysoula Aratzioglou ◽  
Dionisios Gasparatos ◽  
Nicholas Yassoglou ◽  
...  

Two soil mapping methodologies at different scales applied in the same area were compared in order to investigate the potential of their combined use to achieve an integrated and more accurate soil description for sustainable land use management. The two methodologies represent the main types of soil mapping systems used and still applied in soil surveys in Greece. Diomedes Botanical Garden (DBG) (Athens, Greece) was used as a study area because past cartographic data of soil survey were available. The older soil survey data were obtained via the conventional methodology extensively used over time since the beginnings of soil mapping in Greece (1977). The second mapping methodology constitutes the current soil mapping system in Greece recently used for compilation of the national soil map. The obtained cartographic and soil data resulting from the application of the two methodologies were analyzed and compared using appropriate geospatial techniques. Even though the two mapping methodologies have been performed at different mapping scales, using partially different mapping symbols and different soil classification systems, the description of the soils based on the cartographic symbols of the two methodologies presented an agreement of 63.7% while the soil classification by the two taxonomic systems namely Soil Taxonomy and World Reference Base for Soil Resources had an average coincidence of 69.5%.


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