MORPHOLOGICAL AND PHYSICO-CHEMICAL PROPERTIES OF SOILS DEVELOPED ON BASALTIC PARENT MATERIAL IN JOS SOUTH, PLATEAU STATE 1Mamzing, D., 1Loks, N.A., 1Da’ar, J.W., 1Daboro, P.C 2Rotbe, G, 2Deme, P.N. and 3Zata, A.I

International Journal of Innovations in Sustainable Development, Volume 7, Number 2, 2016

ISSN: 2026-801X

MORPHOLOGICAL AND PHYSICO-CHEMICAL PROPERTIES OF SOILS DEVELOPED ON BASALTIC PARENT MATERIAL IN JOS SOUTH, PLATEAU STATE

¹Mamzing, D., ¹Loks, N.A., ¹Da’ar, J.W., ¹Daboro, P.C ²Rotbe, G, ²Deme, P.N. and ³Zata, A.I

¹Department of Agricultural Technology, Plateau State College of Agriculture, Garkawa

²Department of Basic Studies, Plateau State College of Agriculture, Garkawa

³ Department of Soil Science, School of Agriculture and Agricultural Technology, Modibbo Adama University of Technology Yola, Adamawa State.

ABSTRACT

The study was carried out to investigate morphological and physico-chemical properties of soils developed on basaltic parent material in Jos South in order to help appraise the soil productivity of the area. The aim was to determine the soils properties and characterize them. Detailed soil survey was carried out and rigid grid method was employed for

the survey. Three mapping units were delineated as Mu 1 Mu 2 and Mu 3 and a representative soil profile pit was dug in each mapping unit and studied. Morphological properties were determined from in situ examination of the soil profile pits. Soil samples were collected according to pedogenetic horizons and analyzed for physical and chemical properties. Results showed that the soils were deeps fine textured, strong, fine and has blocky structures and generally had trown colour. Bulk density was found to be low in all the mapping units, pH values of Mu 1, Mu 2 and Mu 3 has means of 5.0 5.4 and 5.4 respectively, indicating strong acidity. Moderate to high values of total nitrogen, available phosphorus, cation exchange capacity and exchangeable bases were observed in all the mapping units. Mu1, Mu 2 and Mu 3 were characterized and classified as Eutric Haplustults, Eutric Paleustults and Typic Haplustults respectively. The soil fertility potential of the soils had acidity as a constraint which can be ameliorated by substituting the use of nitrogenous fertilizers with organic fertilizer, regular buildup of exchangeable bases through application of sulphate and phosphate fertilizers can sustain the fertility potential of the soils.

Keywords: Morpholigical and Physico-Chemical properties, basaltic soil classification

INTRODUCTION

          Soil is a fundamental resource base for agricultural production systems. Besides being the main medium for crop growth, soil functions to sustain crop productivity maintain environmental quality and provide for plant, animal and human health. If is in respect of this study on soil properties in particular morphological and physico-chemical properties will provide basic information for better plant growth and management of the soil resources. A parent material is the starting point for a soil and the degree of development of a soil is measured by the amount of change compared with its parent material (Retallack, 1990). Kparmwang, (1993) and Olowolafe, (1994) reported that most soil on the Jos Plateau developed on two types of parent materials, namely: basalt and granite. The Basaltic parent material originated form igneous parent rock which formed form eruption and cooling of molten material through an intense process of volcanism. Basalt has a fine-grained mineral texture due to the molten rock cooling too quick for large mineral crystals too grow. It is often porphtrictic, contains larger crystals (phenocrysts) formed prior to the extrusion that brought the magma to the surface, embedded in a finer-grained matric.

          Morphological properties of soils entail those properties that can only be seen and assessed. Over the years, morphological properties of soils have been studied alongside physical properties of soils without clear distinctions. However, Esu, (1999) distinctively recognized the following properties as soils morphological properties. Soil depth, cutans pores, colour, roots inclusions and horizon boundary characteristics. Similarly, Julio et al, (2008) during field survey admitted evaluating soil morphological properties such as texture, structure, consistence, cutans

Morphological and Physico-Chemical Properties of Soils Developed on Basaltic Parent Material in Jos South, Plateau State

and colour. They further revealed that it is difficult to assess these soil properties using numerical methods.  

          The physical properties of a soil are the result of soil parent materials being acted upon by climatic factors (rainfall and temperature), and affected by topography and life forms especially soil animals over a period of time (AZ Master Gardener manual, 1998). Several reports on phusical properties of soil which include: texture, structure, bulk density, particle density, porosity, water content and consistence are known as dominant factors affecting the use of the soil (Ojanuga and Awujoola, 1981).

          The property which entails how a soil holds essential minerals is a basic chemical property of every soil and is related directly to electrical charges of atoms and molecules in the soil usually associated with clay particles in the soil and with the soil organic matter (Bishop et al, 1983). Soil chemical properties relates to parameters such as: pH, electrical conductivity (EC), exchangeable cations (Mg, Ca, K and Na), Cation exchange capacity (CEC) organic carbon, available phosphorus, total nitrogen and available micronutrients.

MATERIALS AND METHODS

Description of the Study Area,    

          The study was carried out at the volcanic land scape in the premises of National Veterinary Research Institute, Vom (Easting Coordinate 0475700, Northing Coordinate 1074515) in Jos South, which is located in the central part of Nigeria between latitude 8⁰, 30¹ and 10⁰, 10’N and longitude 8⁰ 20¹ and 9⁰ 30’E (figure 1 and 2).  The study area has a surface area of about 5,200km² and has an average elevation of about 1,250 meter above mean sea level and stands at an altitude of about 600 meter above the surrounding plains. Tropical wet and dry climate characterized the area with long-term annual rainfall of 1260mm with mean annual temperature of about 22⁰C and mean relative humidity of 45.63%. Jos South lies within the Northern Guinea Savannah vegetation zone, which is open woodland predominantly covered with different types of tree species, herbs and shrubs (Olowolafe, 2003). The geology of the area comprises pre-cambrian basement complex rocks mainly gneiss and older granites which have been eroded to expose the younger granite of Jurassic age. Tertiary and quarternary volcanic rocks (mainly basalts also occur in Jos South. The basalts are almost completely decomposed and denuded so that only a few remnants are preserved, forming flat-topped hills (Olowolafe. 1994).

Field Work

          In this study, detailed survey was carried out and a rigid grid survey method was employed for the survey work as described by Dent and Young, (1981). Three mapping units were delineated as Mu1, Mu 2 and Mu 3 and representative profile pits were hand dug to specification 2meters long, 1.5 meters wide and 2meters deep (where possible)  (2m x 1.5m x 2m). The pits were described for their morphological properties which include soil colour, texture, structure, consistence, horizon boundary conditions and miscellaneous features such as roots, pores, mottles etc. thereafter, eleven soil samples were collected according to the pedogenetic horizons for laboratory analyses.

Laboratory Analyses

          The soil samples were air dried, ground and screened using a 2mm sieve. Particle size distribution of the soils was determined by the hydrometer method (NSSC, 1995). Soil colour was determined by munsell at both moist and dry conditions of soils. Bulk density was determined by the core method (black, 1965). Particle density was determined using the pycnometer method (Blake and Hartge, 1986) while porosity was calculated as

F = 1- Db x 100

          DP

International Journal of Innovations in Sustainable Development, Volume 7, Number 2, 2016

CEC was determined after extraction with ammonium acetate (Jaiswal, 2003). The PH was determined in a 1:2.5 soil-water suspension ratio using glass electrode (IITA, 1979). The electrical conductivity of the soil samples was measured alongside pH with an EC meter using the same soil-water suspension (Jaiswal, 2003). Organic carbon was determined using Walkley  and Black wet Oxidation method, while total nitrogen was determined by the Microkjeldhal method (Bremer and Mulvaney, 1982). Available phosphorus was analyzed using the Bray N0.1 procedure (Black, 1965). Total exchangeable acidity was analyzed using INKCL extraction and titration (Mclean, 1965). The exchangeable cations were determined in the extract of IN neutral ammonium acetate (NH4 0AC) and the concentrations of Ca and Mg were read from Atomic Absorption Spectrophotometer while K and Na were determined using flame photometer (Black 1965). Total exchangeable bases were calculated by summing up the total exchangeable bases and the total exchangeable acidity (Black, 1965). Percentage base saturation was calculated by dividing the total exchangeable bases by effective cation exchange capacity and multiplying the answers by 100 (Jaiswal, 2003).

RESULTS AND DISCUSSION

Soil Morphological Properties

The morphological properties of the Soils are presented in Table 1. Soil profile depths of Mu1, Mu 2 and Mu 3 were 135cm 150cm and 145cm respectively, indicating that the profiles were relatively deep, thus agreeing with the report of Olowolafe, (1994) that the basaltic derived soils have relatively deep profiles, well drained and well structured. The generally deep nature of the basaltic soils is owed to the fact that the basalts are deeply weathered (Retallack, 1990). Generally, the soils were characterized by brown, dark brown and reddish brown moist soil colours, loamy and clay loamy textures with crumb and sub angular blocky structure. The consistencies were slightly sticky to very sticky when wet, friable to firm when moist and hard when dry. This is similar to the findings  of Kparmwang, (1993) and Soil Survey Staff, (1995) who reported that soils on new basalts had dark reddish brown colour and are generally sticky and plastic when wet, very friable to friable when moist and hard when dry. The brown colour might have resulted from the presence of iron (Fe) oxides (Boucot et al, 1974) and (Retallack, 1990). The occurrence of loam texture and crumb structure at the Ap horizon of all the mapping units may be due to cultivation which changed the original structure of the soils. The horizon boundary conditions in all the mapping units were clear and smooth at the Ap horizon and diffuse and wavy at the lower horizons as also reported by Ojanuga and Awujoola, (1981). This clear boundary distinction between Ap horizon and the lower horizons has due to melanization by organic matter in the Ap horizon. 

Soil Physical Properties

          The Sand fraction of Mu1, Mu2 and Mu3 had means of 36.23%, 33.05% and 39.9% indicating high sand fractions in all the mapping units (Table 2) However, the silt and clay percentages which were all averagely high combined to give the soils fine texture, confirming the work of Retallack, (1990) that basalt derived soils have fine grain size. The clay fraction was not higher than other fractions in contrast to Olowolafe, (2003) who reported that basalt derived soils have higher contents of clay. Also, Hassan et al, (2015) recorded low values for sand fractions and high values for clay and averagely high values for silt in basaltic soils of Jos Plateau state. The relatively high sand fractions may be due to the nature of land use (intensive cultivation) which resulted to leaching of fine soil particles and clay fractions, resulting in this marked difference. However, an irregular distribution trend for sand, silt and clay within the profiles was observed in the study. Bulk density was generally low (Mu1, Mu 2 and Mu 3 had means of 0.96gcam^-3, 0.97gcm^-3 and 0.94gcm^-3 respectively) (Table 2) as rightly observed by Olowolafe, (2003) that basalt derived soils have low bulk density.

Morphological and Physico-Chemical Properties of Soils Developed on Basaltic Parent Material in Jos South, Plateau State

Soil Chemical Properties

          Generally, the soils were acidic as the mean pH values for all the mapping units are less than 5.5 (Table 3). Low values were also reported by Eshett, (1987) on basaltic soils at Ikom in the humid forest zone (range 4.6 to 5.2). high rainfall being recorded in the study area may be responsible for leaching of the basic cations which resulted in low pH values. Also, intensive cultivation and continuous use of nitrogenous fertilizers in the study area may be among factors that precipitated the acidity. The mean values of electrical conductivity. (EC) in Mu 1, Mu 2 and Mu 3 were very low (0.088dsm^-1, 0.03dsm^-1 and 0.058dsm^-1 respectively) (Table 3). This may be due to the inherent properties of the parent material. The high content of organic carbon in Mu1, Mu 2 and Mu 3, having means of 1.70kg^-1, 1.18gkg^-1 and 1.07gkg^-1 respectively (Table 3) with a correspondingly moderate to high total nitrogen having means for Mu 1, Mu 2 and Mu 3 as 0.19%, 0.13% and 0.11% respectively (Table 3) might have resulted from intensive crop production which leaves heavy plant debris on the surface of the soil. However both organic carbon (OC) and total nitrogen (TN) decreased with depth as also observed by Hassan, et al, (2015). Means of available phosphorus of Mu 1, Mu 2 and Mu 3 (10.73ppm, 7.34ppm and 9.10ppm respectively) were moderately high as also reported by Retallack, (1990) that soils developed on basaltic parent material have high available phosphorus due to high phosphate content of the parent material.  Ca, Mg, Na and K mean contents of Mu1 and Mu 2 had moderate to high values which decreased with depth (Table 3). The high values recorded at Ap horizon was due to the marked presence of organic matter at the surface. This contrasted the finding of Hassan et al, (2015), who reported low values. Moderate values were observed for total exchangeable bases (TEB), total exchangeable acidity (TEA)  and effective cation exchange capacity (ECEC) as a result of the moderate contents of exchangeable cations, which are directly related to TEB,CEC and ECEC (kilmer, 1990). Similarly, percentage base saturation, which is also directly related to exchangeable cations was high in all the mapping units. This gives Mu 1 and Mu 2 high potentials for sustainable crop production. However, the mean values for EC, OC and TN in Mu3 were lower than in Mu 1 and Mu 2 (Table 3). This was so because the mapping unit was not put under intensive crop production, thus there was no plant debris to contribute to OC. However, all other parameters had almost the same contents as in Mu 1 and Mu 2 with slight difference which might not be significant.

Soil Classification

          The USDA soil Taxonomy diagnostic criteria for soil classification was used in classifying the soils (Soil Survey Staff, 1998). Soils of Mu1 had an Ap horizon with base saturation calculated from neutral ammonium acetate to be >50%. The soils had low pH values (acidic), therefore stood out as Ultisols at the order level. The study also showed that the soil moisture regime was dry (ustic) (Okoye, et al, 1983), qualifying the soils as Ustults at the sub order level the pedon was simple (Hapl) because it had few horizons thus the soils were classified as Haplustults at the great group level. Because the soils has high base saturation (Eutric), the soils keyed out at the sub-group level as Eutric Haplustults.

          Similarly, the low pH values also characterized Mu 2 just like any other Ultisols, with base saturation calculated from neutral ammonium acetate to be > 50%. Thus, the soils were regarded as Ultisols at the order level. The soils were observed at dry soil moisture regime (Ustic) and so that qualified the soils to be Ustults at the suborder level. The pedon appeared to be an old development (Pale), thus at the great group level, the soils were classified as Paleustults. The high base saturation. (Eutric) characteristic of the soils further classified them at the sub group level as Eutric Paleustults.

          Mu 3 was acidic and so the soils qualified as Ultisols at the order level. The moisture regime was ustic, thus the soils keyed out as Ustults at the sub order level. At the great group level, the soils were classified as Haplustults, owing to their simple nature. The mapping unit was

International Journal of Innovations in Sustainable Development, Volume 7, Number 2, 2016

typical of the basaltic parent material in all characteristics therefore qualified the soils to be classified as Typic Haplustults.   

CONCLUSION

          Generally, soils developed on basaltic parent materials in Jos South were deep, fertile thus have potentials to sustain crop production but have acidity problems. However, with more pressure on land use for agriculture owing to population explosion, nutrient depletion will certainly set in and the soil will degradate unless sound soil management strategies are put in place to check the condition against total loss of crop productivity and degradability of the soil quality. If crop production must be sustained and soil quality maintained, improved soil management practices like regular buildup of the exchangeable bases through application of sulphate and phosphate fertilizers and the use of organic fertilizers must be encouraged.  

Morphological and Physico-Chemical Properties of Soils Developed on Basaltic Parent Material in Jos South, Plateau State

Table 1: Morphological Properties of Soils Developed on Basaltic Parent Material in Jos South, Plateau State

Mapping unit	Horizon designation	Profile depth (cm)	Soil colour (moist)	Tex.   class	Structure	Consistency	Boundary	Miscellaneous observations
1	Ap	0-25	7.5YR 3/2	L	mmcr	wss    mvfr     ds	cs	Common medium roots.
	AC1	25-57	7.5YR 4/6	CL	sfsbk	wvs    mf        dh	dw	Common medium roots.
	AC2	57-135	7.5YR 7/6	CL	sfsbk	wvs    mf        dh	dw	Few fine roots and concretions.
2	Ap	0-15	7. 5YR 4/2	L	mmcr	wss     mvfr    ds	cs	Common medium roots.
	AC1	15-35	7. 5YR 4/4	CL	sfsbk	wvs     mf       dh	dw	Few medium roots.
	AC2	35-88	7.5YR 5/4	C	Sfab	wvs     mf       dh	cs	Few medium roots.
	C	88-150	7.5YR 5/4	SCL	mmsbk	wss     mvfr    ds	dw	Few medium roots and fine concretions.
3	Ap	0-12	7.5YR ¾	L	mmcr	wss     mvfr     ds	cs	Many fine and medium roots.
	AC	12-34	7. 5YR ¾	CL	sfsbk	wvs     mf        dh	dw	Common coarse concretions and few fine and distinct mottles.
	C1	34-93	7. 5YR 4/6	CL	sfsbk	wvs     mf        dh	dw	Common coarse concretions and few fine distinct mottles.
	C2	93-145	7. 5YR 4/4	SCL	sfsbk	wv        mf      dh	dw	Common coarse concretions.

Key: Texture: Tex. = textural, C = Clayey, CL = clayloam, SL = sandyloam, SCL = sandy clayloam, SiC = siltyclay, L = loamy, S = sandy

Structure: 1^stm = moderate, 2^nd m = medium, s = strong,  sbk = subangular blocky, ab = angular blocky, cr = crumb f = fine

Consistency: w = wet, ns = non sticky, np = non plastic, s = sticky, sl = slightly, f = firm, fr = friable, v = very, m = moist, d = dry, h = hard 2^nd s = soft

Boundary: c = clear, s = smooth, d = diffuse, w = wavy

International Journal of Innovations in Sustainable Development, Volume 7, Number 2, 2016

Table 2:  Physical Properties of Soils Developed on Basaltic Parent Material in Jos South, Plateau State

M U              Horizon         Profile Depth            (Particle Size Distribution    (%)  )                BD           PD           Total porosity

		(cm)	Sand	Silt	Clay	(gcm-3)	(gcm-3)	(%)
1.	Ap	0-25	40.30	37.00	22.70	0.93	2.20	58
	AC1	25-57	30.00	31.00	39.00	0.98	2.23	56
	AC2	57-135	38.40	32.30	29.30	0.96	2.40	57
	Mean		36.23	33.43	30.33	0.96	2.28	57
2.	Ap	0-15	29.50	45.50	25.00	0.96	2.20	56
	AC1	15-35	32.50	35.40	32.10	0.97	2.32	58
	AC2	35-88	19.00	30.30	50.70	1.00	2.35	57
	C	88-150	51.20	23.00	25.80	0.96	2.40	56
	Mean		33.05	33.55	33.44	0.97	2.32	56.75
3.	Ap	0-12	49.20	17.00	33.80	0.82	2.24	63
	AC	12-34	31.30	29.70	39.00	0.95	2.32	59
	C1	34-93	30.00	31.60	38.40	1.00	2.41	59
	C2	93-145	49.20	25.00	25.80	0.99	2.36	58
	Mean		39.93	25.83	34.25	0.94	2.33	59.75
	Total Mean		36.42	30.71	32.87	0.96	2.31	57.91

MU= mapping unit

Morphological and Physico-Chemical Properties of Soils Developed on Basaltic Parent Material in Jos South, Plateau State

Table 3: Chemical Properties of Soils Developed on Basaltic Parent Material in Jos South, Plateau State

MU     Horizon     Depth        pH      EC        O.C     T.N     AVP      (                               cmol (+) kg^-1                                     )      BS

                          (cm)      (H₂0)      (dsm^-1)  (gkg^-1)   (%)    (ppm)     Ca²⁺     Mg²⁺     Na⁺        K⁺      TEB     TEA      CEC     ECEC   (%)

1	Ap	0-25	5.1	0.050	2.15	0.22	11.90	2.01	1.79	0.89	0.42	5.11	2.10	7.49	7.21	68
	Ac1	25-57	4.8	0.170	1.54	0.20	10.50	2.11	2.75	0.85	0.30	6.01	2.20	7.00	8.21	86
	Ac2	57-135	5.1	0.044	1.40	0.15	9.80	1.71	1.49	0.56	0.24	4.00	0.90	6.10	4.90	66
	Mean		5.0	0.088	1.70	0.19	10.73	1.94	2.01	0.77	0.32	5.04	0.73	6.86	6.77	77.33
2.	Ap	0-15	5.0	0.054	2.00	0.20	6.80	2.91	1.89	0.83	0.43	6.06	2.20	7.13	8.26	85
	Ac1	15-35	5.4	0.038	1.00	0.14	5.40	2.31	1.79	0.89	0.25	5.24	2.70	6.79	7.94	77
	Ac2	35-88	5.4	0.026	1.00	0.13	8.75	1.21	1.99	0.77	0.23	4.20	1.20	6.50	5.40	65
	C	88-150	5.6	0.026	0.70	0.06	8.40	0.51	1.49	0.89	0.30	3.19	1.70	5.26	4.89	61
	Mean		5.4	0.036	1.18	0.13	7.34	1.74	1.79	0.85	0.30	4.67	1.95	6.42	66.66	72
3.	Ap	0-12	5.1	0.046	1.40	0.14	8.40	4.41	1.89	0.61	0.13	7.04	1.50	8.25	8.54	85
	Ac	12-34	5.6	0.120	1.30	0.13	10.50	3.21	1.69	0.50	0.20	5.60	3.00	7.20	8.60	78
	C1	34-93	5.6	0.024	1.20	0.12	9.10	1.11	1.79	0.90	0.22	4.02	2.20	5.67	6.22	71
	C2	93-145	5.3	0.042	0.36	0.04	8.40	1.11	1.89	0.49	0.21	3.70	2.40	6.55	6.10	56
	Mean		5.4	0.058	1.07	0.11	9.10	2.46	1.82	0.63	0.19	5.09	2.28	6.92	7.37	72.5
	TotalMean		5.3	0.058	1.28	0.14	8.90	2.06	1.86	0.74	0.27	4.92	2.01	6.72	6.93	72.5

                                 

International Journal of Innovations in Sustainable Development, Volume 7, Number 2, 2016

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Morphological and Physico-Chemical Properties of Soils Developed on Basaltic Parent Material in Jos South, Plateau State

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