CHARACTERIZATION, CLASSIFICATION AND SUITABILITY EVALUATION OF SOME SOILS IN THE FLOODPLAINS OF RIVER NIGER, KOGI EAST, NIGERIA FOR RICE, MAIZE, CASSAVA AND OIL PALM PRODUCTION

This study was conducted to characterize, classify and evaluate four soils along River Niger in Kogi East for rice, maize, cassava and oil palm production. The soils developed predominantly from alluvium. The soils were located in four communities namely Ejule-Ojebe, Shintaku, Bagana and Kpata all in the floodplains of River Niger in Kogi East. The soils were investigated using a free survey technique. Four pedons representing four soils located at different sites in the floodplain were studied. The environs and the profiles of the soils were described according to standard field procedures. Soil samples were then taken from genetic horizons for laboratory analysis. The soils were also characterized and classified according to Soil Taxonomy and the World Reference Base for Soil Resources (WRB). The colour of the soils ranged from shades of brown to grey generally due to poor drainage. The soils also varied in depth and horizonation due to differences in profile development. Due to the relatively higher sand content of the soils, especially in the surface and subsurface horizons, the texture of the soils generally ranged from sand to clay loam. The pH (H 2 O) of the soils ranged from 4.8 to 7.3, strongly acidic to slightly alkaline, and tended to increase with depth. The soils contained moderate amounts of organic carbon in the surface soils but lower levels in the lower horizons. Based on their properties, the soils were classified according to Soil Taxonomy as Alfisols (Ejule-Ojebe), Entisols (Shintaku), Inceptisols (Bagana) and Alfisols (Kpata) and according to WRB as Planosols, Arenosols, Gleysols and Planosols, respectively. The soils were found to be highly suitable for rice production but moderately suitable for maize, cassava and oil palm. Apart from rice cultivation, wetness of soil was found to be the major limiting factor for optimum rainfed cultivation of maize, cassava and oil palm.


INTRODUCTION
Characterization of soils gives detailed information about the different soil properties and identifies their potentials and production constraints. Soil characterization has been reported to be the first aspect/study discipline towards developing database for formulating land use models (Bassanta et al., 2013). Soil characterization studies are a major building block for understanding the soil and classifying it for getting the best knowledge of the environment (Akamigbo, 2005). Thus, soil characterization provides information on morphological, physical and chemical properties of soils as well as insights into their behaviour (dynamics) (Raju et al., 2005). Soil classification is the systematic arrangement of soils into categories based on their properties. The purposes of classification include organizing knowledge for ease of remembering properties used and clearer understanding of relationships between soils (Buol et al., 1997). For technical classification which is used in the FAO/UNESCO (WRB) system, the purpose may be for specific application such as land-use regulation (Buol et al., 1997). This knowledge is essential for utilizing soil potentials (Kumar et al., 2013). It provides a powerful resource for the benefit of mankind especially in the area of food security and environmental sustainability. Soil suitability evaluation involves characterizing the soils in a given area for specific land use type (Ande, 2011). To assess the suitability of soils for crop production, soil properties and crop requirements must be known. Also, these requirements must be understood within the context of limitations imposed by landforms and other features which do not form a part of the soil but may have significant influence on use that can be made of the soil (FAO, 1976).
The dearth of adequate information on the physicochemical of the soils of the study area is a contributory challenge towards achieving the goal of maximum productivity (Amhakhian and Osemwota, 2012). Characterization, classification and suitability evaluation of the soils of this region for agricultural purposes will not only establish relationship between soil properties and the landscape parameters, but also provide preliminary information on the nutrient status, limitations and ensure sound judgement on the behaviour or response of the soils to specific uses. The objectives of this research were to characterize, classify and evaluate the suitability of four soils in the floodplain of River Niger at Kogi East, Nigeria for the cultivation of rainfed rice, maize, cassava and oil palm.

Study Area
The study sites were located at Ejule-Ojebe, Shintaku, Bagana and Kpata all within the Eastern zone of the Kogi State. This zone falls in the middle belt of Nigeria. It lies between latitudes 6°51′N to 7°54′N and longitudes 6°45′E to 7°38′E. Kogi East is bounded on the West by Niger River, North by the River Benue, East by Benue State and South by Anambra State. The study area experiences two major climatic seasons namely the rainy season which lasts from Apr. to Oct. and the dry season which starts from Nov. and ends in Mar. (Weatherbase, 2011). Part of the dry season is very dusty and cold as a result of the north-easterly winds which bring about the harmattan. The annual rainfall ranges from 1100 to 1300 mm with mean of 1200 mm. The average monthly temperature varies between 17 and 36°C (Amhakhian and Osemwota, 2012). The highest temperature (36°C) has been recorded during the dry season (Gideon and Fatoye, 2012). The mean relative humidity in the study area falls to a minimum of 15% in the dry season and rises to a maximum of 67% in the rainy season (Gideon and Fatoye, 2012).
The geology of the area comprises two main rock types namely basement complex rocks and older granite extending towards the lower Niger valley. The various sedimentary rocks of River Niger and Benue extend southeastwards through Enugu and Anambra States (www.onlinenigeria.com). Amhakhian and Osemwota (2012) reported geological formations of Cretaceous age within the study area. A study of sediment geochemistry of River Okura confirmed study area as falling within the Anambra sedimentary basin which is Cretaceous in age (Gideon and Fatoye, 2012). The study further revealed that the rocks had low silica (SiO2) but high iron (Fe) content suggesting lithic arenite type of sandstone. Some parts of the study area have also been found to be made up of geologic materials such as Awgu shale group (Fagbami and Akamigbo, 1986;Ukabiala, 2012). The area is naturally drained to the Niger and Benue Rivers through their tributaries, rivers and streams forming various lowlands and floodplains.

Field Study
In general, landscape carrying the floodplain soils within Kogi East covers the area adjoining Rivers Benue and Niger at Ejule-Ojebe, Shintaku, Bagana and Kpata in Ibaji, Bassa and Omala Local Government Areas. They are areas that are seasonally inundated by surface or ground water. They are lowlying at an elevation ranging from 38 to 59 m above mean sea level. The soils are derived from mostly sand, clay and other forms of alluvial and colluvial deposits. Depending on the topographic positions, the soils are poorly to moderately drained. They are nearly level to level plain (2 to 4% slope). Four pedons which fall within the floodplain in Kogi East were selected and designated at Ejule-Ojebe, Shitaku, Bagana and Kpata (Figure 2), following the physiographic pattern of the landscape. The agroecology is wetland while the geology is recent alluvium. The relief is characterized by nearly level to gently undulating plains. The soils are poorly drained and made up of dominantly sand, sandy loam, loamy sand or sandy clay loam surfaces. The profiles at Ejule-Ojebe and Kpata were dug to 200 cm while those at Shintaku and Bagana were 35 and 60 cm deep, respectively due to the presence of perched water table in the two soils. The locations of the pedons of the four soils were georeferenced with a hand-held Etrex High Sensitivity Global Positioning System (GPS). The soil profile pits and their environs were described following Field Book for Description and Sampling Soils (Schoeneberger et al., 2012). Abney level was used to determine the slope angles on the sites of the soil profile pits. Core samples were taken in duplicates from the surface and subsurface horizons of each soil profile for the determination of selected physical properties. Soil samples were collected from the pedogenic horizons starting from the base of the profiles to avoid contamination. The soil samples collected were preserved in labelled polyethylene bags and transported to the University of Nigeria Nsukka Soil Science Laboratory for physicochemical analyses.

Laboratory Analyses
The particle size distribution (PSD) of the soils (< 2 mm) was determined using Bouyoucous (1962) hydrometer method. Sodium hydroxide was used as dispersant and then the textural classes were read out from the USDA soil textural triangle. Bulk density was determined by the core and excavation method described by Landon (1981). Soil porosity was calculated with the values of the bulk density using the method outlined by Vomicil (1965) and Brady and Weil (2002). Soil saturated hydraulic conductivity (Ksat) was determined based on Klute and Dirksen (1986) method and calculated by using the transposed Darcy's equation for vertical flows of liquids: where Ksat is saturated hydraulic conductivity (cm h -1 ), Q is steady-state volume of water outflow from the entire soil column (cm 3 ), A is cross-section area (cm 2 ), t is time interval (h), L is length of the sample (cm), and ∆H is change in the hydraulic head (cm).
Soil pH was determined in water and 1N KCl solution in a soil solution ratio of 1:2.5 using a glass electrode pH meter (McLean, 1982). Organic carbon was determined by the wet dichromate acid oxidation method (Nelson and Sommers, 1982). Total nitrogen content was estimated by using the macro-Kjeldahl digestion method (Bremmer and Mulvaney, 1982). The available phosphorus content was determined according to the Bray II bicarbonate extraction method (Olsen and Sommers, 1982), using 0.03 N ammonium fluoride with 0.1N HCl. The phosphorus in the extract was determined with a photo-electric colorimeter. Exchangeable bases (Ca, Mg, K and Na) were extracted with 1N NH4OAc (pH 7.0) using 1:10 soil-solution ratio. The levels of K + and Na + in the extract were determined with the flame photometer while the levels of Ca 2+ and Mg 2+ were determined with the atomic absorption spectrophotometry (Thomas, 1982). Total exchangeable bases (TEB) were obtained by the summation of the exchangeable bases (Na + , K + , Ca 2+ and Mg 2+ ) (Rhoades, 1982). The cation exchange capacity of the soils was determined with 1N NH4OAc, pH 7.0 (Rhoades, 1982).
Exchangeable sodium percentage (ESP) was calculated by the formula of Soil Survey Staff (1999):
Exchangeable acidity was determined using the method outlined by Thomas (1982). Extraction was done with 1 N KCl and the extract titrated with 0.05 N NaOH to a permanent pink end point using phenolphthalein. Effective cation exchange capacity (ECEC) was determined as a summation of TEB and exchange acidity (Rhoades, 1982). The percentage base saturation (PBS) of the soils was determined as; PBS = (TEB/CEC) × 100 (Rhoades, 1982). The values obtained from analysing the chemical properties of the soils were compared with critical limits used for interpreting soil fertility (Table 1).   Enwezor et al. (1989). Ca 2+ , Mg 2+ , K + , Na + -exchangeable calcium, magnesium, potassium and sodium; CEC -cation exchange capacity, ECEC -effective cation exchange capacity, EA -exchangeable acidity, Org. C -organic carbon, Total N -total nitrogen, Avl. P -available phosphorus, BS -base saturation, ESP -exchangeable sodium percentage

Soil Classification
The soils were classified according to the Keys to Soil Taxonomy (Soil Survey Staff, 2014) and the World Reference Base for Soil Resource (IUSS Working Group WRB, 2015).

Morphological Characteristics of the Soils
The morphological characteristics of the soils studied are shown in Table 7. The boundaries between the identified soil horizons varied between clear smooth, diffuse smooth, gradual wavy, gradual irregular and abrupt irregular. The moist colour of the soils in this flood plain was dominated by hues of 10YR, 7.5YR and 2.5Y in the surface and subsurface layers except 5B in Bagana profile. These gave variation of colours such as 10YR5/2 (greyish yellow brown), 10YR6/3 (dull yellow orange), 7.5YR7/2 (pinkish grey), 2.5Y6/6 (olive yellow), and 5B5/1 (bluish grey).
The field texture observation (feel method) showed variation of clay, clay loam, loamy sand and sandy clay loam in the surface and subsurface soils with a discontinuity observed in Bagana profile as expressed by sharp textural difference of underlying silty loam from the surface. Soil structural variations of various grades and classes of granular crumb and subangular blocky structure were observed. Single grain structure was observed in the surface and subsurface soils of Shintaku profile. The consistence throughout the profiles varied from non-sticky and non-plastic to very sticky and very plastic in both surface and subsurface horizons under wet condition and loose to friable under moist condition. Other morphological characteristics observed in the profiles studied included roots, manganese concretions and surface cracks of about 5 × 12 cm in Ejule Ojebe and Bagana profiles. Tables 8 and 9 show the physical characteristics of the soils while Figure 2 shows the sand and clay distribution down the profiles of the soils. In all the profiles studied, coarse sand, sand, silt and clay fractions of the soils had ranges of 120 to 410 g kg -1 , 250 to 600 g kg -1 , 20 to 350 g kg -1 and 0 to 280 g kg -1 in the surface soils, 10 to 400 g kg -1 , 270 to 640 g kg -1 , 20 to 390 g kg -1 and 0 to 400 g kg -1 in the subsurface soils respectively. The surface soils had a mean value of 250 g kg -1 for coarse sand. The subsurface soils had respective mean value of 425, 199 and 236 g kg -1 for fine sand, silt and clay. The dominant soil textural classes are clay loam and loamy sand in the surface soil, and sand, sandy clay loam and clay in the subsurface soils.

Physical Characteristics of Soils
The bulk density of the soils ranged from 1.21 to 1.52 g cm -3 and 1.27 to 1.86 g cm -3 with mean values of 1.39 and 1.59 g cm -3 in the surface and subsurface soils, respectively. The percentage total porosity values of the soils ranged from 46.96 to 53.01% with a mean value of 46.96% in the surface and 28.12 to 51.21% (mean: 39.33%) in the subsurface. The Ksat values ranged from 1.32 to 2.91 and from 1.02 to 2.82 with mean values of 2.17 and 1.97 in the surface and subsurface soils, respectively.

Chemical Characteristics of the Soils
The chemical characteristics of the soils are presented in Table 10. The pH in H2O and KCl increased with depth, having higher mean values of 6.0 and 4.9 in the subsurface soils. The organic carbon (OC), total nitrogen (TN) and carbon:nitrogen (C:N) ratio of the soils had ranges of 0.20 to 51.0 g kg -1 , 0 to 0.88 g kg -1 and 0 to 15 at the surface, and 0.20 to 15.60 g kg -1 , 0 to 0.33 g kg -1 and 0 to 13 in the subsurface soils. The mean values of OC, TN and C:N were higher in the surface soils, having 21.40 g kg -1 , 0.34 g kg -1 and 7 than 4.70 g kg -1 , 0.08 g kg -1 and 6 in the subsurface soil, respectively. Available phosphorus (AvP) was irregularly distributed within the depths in all the profiles, varying from 1.87 to 5.60 mg kg -1 at the surface and 1.87 to 18.65 mg kg -1 in the subsurface. The highest value of 18.65 mg kg -1 occurred in the subsurface of Egule-Ojebe soil. The AvP mean value of 4 and 8.07 mg kg -1 was recorded in the surface and subsurface soil respectively.
Total exchangeable bases (TEB) were higher in the subsurface soils, having mean value of 14.46 cmolc kg -1 than 12.48 cmolc kg -1 of the surface soils. The TEB was dominated by Ca 2+ and Mg 2+ which increased down the profiles. Higher value of Ca 2+ (17.80 cmolc kg -1 ) was recorded in the soil from Ejule-Ojebe. The soil exchangeable acidity (EA) was dominated by H + . There were no traces of Al 3+ in the soils of this mapping unit. The EA was higher at the surface soils (range, 0.08-1.80 cmolc kg -1 ; mean, 0.93 cmolc kg -1 ) compared with the subsurface soils (range, 0.16-1.40 cmolc kg -1 ; mean, 0.71 cmolc kg -1 ).
The values of CEC by NH4AOc were higher than the ECEC which irregularly increased with depth. The CEC and ECEC mean values were 28.70 and 13.59 cmolc kg -1 in the surface soils, 25.94 and 15.13 cmolc kg -1 in the subsurface soils. The percentage base saturation (PBS) generally increased with depth, having mean value of 61 and 62% at the surface and subsurface soils respectively. The surface soils had higher mean exchangeable sodium percentage (ESP) value of 0.61% when compared to subsurface soils with 0.59%.

Classification of the Soils
The summary of the classification of the pedons are presented in Table 11. Ejule-Ojebe pedon has layers 50 cm from the mineral soil surface with aquic conditions for some time in normal years with redox concentrations as well as ochric epipedon and therefore classified as Inceptisol. It is further placed as Aquept having ground water within 100 cm of the mineral soil surface for some time during the year. At the great group level, it is classified as Vermaquept, having about 25% recognizable bioturbation as expressed by wormholes. At the subgroup level, it placed as Typic Vermaquept. The FAO/WRB equivalent of the soil is Gleyic Alisol.
Shintaku pedon had no clear evidence of development of pedogenic horizons by sandyskeletal particle size class and is classified as Entisols. This is a wet Entisols, having occurred on a floodplain along the River Niger where the soils are saturated at some time of the year. Therefore, it is set at the suborder of Aquents. At the great group level, this pedon is classified as Psammenquents, having a sandy texture without redox concentrations. Also, the water table is near the surface for long periods. This Psammaquents had a weakly developed ochric epipedon and no lithic contact within 50 cm of the soil surface, very low exchangeable sodium percentage (5-6%) and therefore set as Typic Psammaquents at the subgroup level of the USDA soil taxonomy. The FAO-WRB equivalence of this pedon is Fluvic Arenosols being a young soil in fluvial deposit with weighted average texture class of sand (fluvic material) from mineral soil surface.
The Bagana pedon in which was just beginning to develop with an ochric epipedon and having formed in loamy and clayey parent materials is placed as Inceptisols at the order level. This pedon is a wet Inceptisols with redox concentrations, and having occurred on a flood plain is placed as Aquepts at the suborder level. This Aquepts has endosaturation and so is set as Endoaquepts at the great group level. 1 -weak, 2 -moderate, 3 -strong, 4 -fine, 5 -medium, 6 -coarse, c -crumb, g -granular, sbk -subangular, abk -angular blocky, sg -single grain. Texture: l -loam, s -sand, c -clay, si -silt, cl -clay loam, sl -sandy loam, scl -sandy clay loam, sc -sandy clay, g -gravelly, v -very, e -extremely, st -stony. Consistency: sp -sticky and plastic, sssp -slightly sticky and slightly plastic, nsnp -non sticky and non-plastic, l -loose, vfr -very friable, fr -friable, f -firm, v -very firm. Pores and Roots: f -few, v -very, m -many, c -common, fi -fine, me -medium, co -coarse. Boundary: a -abrupt, c -clear, g -gradual, d -diffuse, s -smooth, w -wavy, i -irregular, b -broken   The soils are fine textured with surface cracks that were more than 5 mm in thickness and so classified as Vertic Endoaquepts according to the USDA Soil Taxonomy. The FAO-WRB of this pedon is Vertic Gleysols, having gleying properties within 40 cm from mineral soil surface, reducing conditions in some parts of every sub-layer as well as an umbric horizon.
The Kpata pedon has ochric epipedon, argillic horizon and a moderate to high base saturation which classifies it Alfisol at the order level of Soil Taxonomy. This soil is further classified as Ustalf being Alfisol that have as ustic soil moisture regime. At the Great Group level of Soil Taxonomy, the soil is categorized as Paleustalf having in the lower one-half of the argillic horizon with Hue of 7.5YR and chroma of 5 an an abrupt textural change between the eluvial horizon and the upper boundary of the argillic horizon. At the Subgroup level, it is classified as Typic Paleustalf. The FAO/WRB equivalence is Haplic Lixisol. Table 12 shows the suitability evaluation of the soils of the study area for the cultivation of rice, maize, cassava and oil palm. The soils were found to be highly suitable (S1) for rice cultivation but moderately suitable for maize, cassava and oil palm cultivation, with average class scores of 62, 66 and 70, respectively.

Land/Soil Suitability Evaluation for Crops
The major limitations to the optimum production of maize, cassava and oil palm are fertility and wetness properties. The wetness properties include drainage, flood duration and ground water table, while among the fertility parameters, total nitrogen and exchangeable calcium and magnesium had low scores.

DISCUSSION
The soils studied occurred generally in the lowlands of Kogi East. They were normally inundated with water from the River Niger at certain periods of the year. The inundation results in high water table in the soils. The dark colour of the surface horizons of the soils, except Shintaku, reflects their relatively higher organic matter and C:N ratios compared to those of the subsurface soils (Table 10). The presence of redoximorphic features are possible indications of alternate wet and dry conditions that result in the reduction and subsequent release of iron and manganese compounds in the soils (Akpan-Idiok et al., 2013).
Apart from the single-grain soil from Shintaku, the soils had good structure that could support crop growth. The texture in the rooting depth of the soils was predominantly clay loam and loamy sand. The vertical and horizontal variations in the texture of the soils could be due to sedimentation as had been reported for similar soils by Ogban andBabalola (2009) andHossain et al. (2011). The boundaries of the horizons depict nascent stage of profile development as had been reported by Akpan-Idiok (2002). The bulk density, total porosity and Ksat values of these soils are moderate. This may be as a result of the moderate to high contents of organic matter in these soils. Similar findings were documented by Akamigbo (2005) and Egbuchua and Ojobor (2011).
The soil reaction of the soils varied from strongly alkaline to slightly acid. The exchangeable acidity was low while the CEC values were generally high. The low values of phosphorus in the soils may be attributed not only to their acidic nature (Obalum et al., 2012a;Obalum and Chibuike, 2017), but also to the absence of effectual P-fertility management practices. The high values of percentage base saturation of these soils are attributed to the specific cations in soil solution, as similarly reported on various floodplains (Igwe et al., 2004;Akpan-Idiok et al., 2006;Ogban and Babalola, 2009;Akpan-Idiok et al., 2013;Ukabiala et al., 2021).
The C:N ratio of the soils would have been facilitated by the vermic property which placed Ejule-Ojebe pedon as Vermaqualf. The many earthworms found in the pedon facilitate breakdown of organic matter which gives positive pool to mineralization. Movements of the earthworms and other insects in the soils might have enhanced porosity and increased hydraulic conductivity. The soil from Shintaku had a texture of sand and single-grain structure because of the very high (98%) sand content. The pedons had aquic moisture regime which positively influenced their suitability for rice cultivation. Similar suitability evaluation was reported by Ajala et al. (2021). The soils from Ejule-Ojebe, Bagana and Kpata were highly suitable for rice. However, they are moderately suitable for maize, cassava and oil palm due to their fertility/wetness status. Despite the prevailing favourable climate and the moderate suitability of the soils for cassava, the long duration of wetness may cause tubers to rot thereby reducing yield. For oil palm that adapts readily to wet soil environments (Okolo et al., 2019),   (Figure 2b), > 50% porosity and fairly low bulk density, may not be suitable for any of the crops. This situation caused high Ksat (2.72-2.91 cm h -1 ; Table 9). Also, there might have been little time for N to equilibrate in the highly leached Shintaku soil, as evident in the low total N and C:N ratio in the soil (Table 10). Also, the very high sand content of the soil might have contributed to its low CEC (Obalum et al., 2013).
As a general principle, organic matter needs to be increased in the soil in order to sustain soil health under the various land uses. Organic matter promotes the stability of soil aggregates thereby improving structure. Also, it improves soil consistence and microbial properties (Kpamwang, 2008). Organic matter supplies nutrients like N, P and S as well as micronutrients such as B, Cu, Mo, Zn, Mn and Cl (Brady and Weil, 2002). Organic matter may also improve CEC and increase soil pH and buffering capacity (Ukabiala, 2012). Sources of organic matter include farmyard manure, crop residue, mulch and green leaf manures (Akpan-Idiok et al., 2013).
The slash and mulch system may be a suitable alternative to slash and burn which is a predominant practice in most parts of Kogi East (Thomich et al. 1998). If returned to the soil, the mulch materials and crop residues affect soil properties and processes (Lal, 1995). Mulches including crop residues generally enhance nutrients cycling, decrease nutrient losses, improve nutrient use efficiency, increase soil organic matter content, enhance soil structure, and influence soil moisture and temperature regimes (Effiong and Akpan, 2013). Above all, crop residues have no soil health risk but increase soil biodiversity of beneficial microbes and serve as good food for earth worms (Effiong and Akpan, 2013).
The soils are generally suitable for paddy rice production based on their properties. Where gleization occurs, such as Ejule-Ojebe, drainage must first be done if crops other than rice have to cultivated. Making of big mounds may also be used to improve drainage for such crops. Furthermore, rice can be successfully grown in the not-too-good-for-rice Shinkatu soil with the sawah ecotechnology (Wakatsuki et al., 2011a, b;Obalum et al., 2012b); however, the increases in soil aggregate stability due to improved organic matter status may not be expected to be evident in this soil with this ecotechnology .

CONCLUSION
This research aimed at characterization and classification of four soils in the floodplains of River Niger in the Kogi East District of Nigeria. The seasonal inundation of water into these land areas gave rise to variations in the various morphological, physical and chemical characteristics of the soils. The soil colour was dominantly brownish and grey as a result of hydromorphism as indicated by the presence of mottles. The dominant loamy textures of the soils influenced the formation of various grades of sub-angular blocky structure. The presence of cracks and earthworms in the soil profiles was important in the classification of the pedons. The moderate to high organic carbon of the soils positively influenced the bulk density and permeability. The pH values could be tolerable to the crops evaluated. The soils were classified to various subgroups of Alfisols, Inceptisols and Entisols. The findings from suitability evaluation showed that the soils are highly suitable for rice, and moderately suitable for maize, cassava and oil palm production.