soil physical properties: a determinant of soils ...€¦ · environmental problems threatening...

International Journal of Social Sciences. Vol. 12, No.3, October, 2018 Special

125

Soil Physical Properties: A Determinant of Soils Susceptibility to

Gully Erosion Menace in Uyo Metropolis, Akwa Ibom State,

Nigeria

by

1Comfort M. Abraham,

2Unyime Saturday,

3Akan A. Tom and

4Isaac Ibanga

Department of Geography and Natural Resources Management

Faculty of Social Sciences

University of Uyo, Uyo, Nigeria

Abstract This study assessed soils physical properties as the determinant of soil susceptibility to

erosion menace in Uyo Metropolis, Akwa Ibom State, Nigeria. Five gully sample sites and five

non-gully sites were randomly selected from where soil samples were collected at both topsoil (0-15cm) and sub soil (15-30cm) and subjected to laboratory analysis for the determination of

physical properties. The laboratory results of the soil physical properties in gully sites showed that the gully locations had indistinguishable soil characteristics hence; there was not much

variance in soil among the study locations. Generally, the result of this study showed that the

soils consisted of vast fractions of sand contrary to that of non-gully locations. Hence, since sand lacks consistency, soil strength was inevitably weak giving rise to gully erosion menace.

The soils in which the physical properties were within such range were in a loose state,

leading to high erosion, leaching of valuable nutrients and low retention capacity which triggered the development of gullies. It was, therefore, concluded that gully development in

Uyo Metropolis was indeed not unconnected with the vulnerability of soil to rain wash. Hence, it is necessary to adopt soil conservation measures and farming practices which

ensure sustainable soil productivity while maintaining equilibrium between the ecosystem and

regular anthropogenic influence and likewise afforestation should be encouraged; this will reduce sand contents and enriched the soil nutrient thus reducing the risk of gully

development.

Key words: Soil Physical Properties, Soil Susceptibility. Gully Erosion.

1. Introduction

Gully erosion menace has become a subject of discussion among earth sciences in

related disciplines such as, soil science, geography, geology, engineering and

environmental science. Gully menace is manifestation of geomorphic breakdown of soil

International

Journal of

Social Sciences

Abraham, C. M., Saturday, U., Tom, A. A. and Ibanga, I.

126

stability mechanism. Many communities in Nigeria and elsewhere are affected negatively

by rapid gully development. Essien and Essen (2012) indicated that gully erosion is the

most visible form of erosion in Nigeria mainly because of the remarkable impression they

leave on the surface of the earth. As noted by Ofomata (1985) cited in Igbokwe,

Akinyede, Ono, Kneki, Nnodu (2007), areas of high susceptibility to gully development

correspond to geological regions of weak unconsolidated sandy formations while least

susceptible areas are within the consolidated tertiary to recent sediments. Similarly, the

development of gullies leads to the deterioration of soil properties, reduction and loss of

available lands for socio-economic purposes (Danladi, 2014). It is one of the most severe

environmental problems threatening human population across the globe, in particular for

developing countries, with limited resources to cope with land degradation (Ezechi, 2010,

Ezeigwe, 2015).

In Nigeria, about 16,668km2 or 22,8% of the total land mass surface is affected by

extreme form of gully erosion (Fubara, 2012). In the south eastern states, about 25,000

hectares of land are lost annually to fluvial erosion, especially by gullying. In addition, the

topsoil which contains significant proportion of soil nutrients and organic matter is

washed away at alarming rates by insidious erosion of great magnitude (Abraham, 1998,

2010). This impact of gully on soil, the lateritic subsoil being firmer and of more uniform

in particle size than the topsoil, may change the natural pattern of soil erodibility together

with the slight compaction of the surface and may reduce infiltration and concentrate the

upland run-off at the down slope and side slope of the degraded surfaces, thereby

accelerating gully advancement and land deterioration at faster rates. Soil detachment

depends on the make-up of soil properties and rainfall parameters prevalent in the area

(Ezechi, 2010; Essien and Okon, 2011; Abraham and Wilcox, 2014; Abraham and

Ewelike, 2016,

Gully erosion cuts through the topsoil and the subsoil, affecting the importance

physical properties of the soil such as the relative distribution of particle size, soil porosity

and moisture content, and bulk density with resistivity to erosion highly affected. This

land degrading operation through the impact of gully development removes the sod or

vegetation cover and opening of the bare soil, to be impacted more by external forces

such as sunshine and rainfall (Essien and Okon, 2011). The alternative wetting and drying

of the soil physical properties within the gully channel leads to loss of plasticity, slaking

and weakening their resistance to raindrop impact (Udosen, 2014). Anthropogenic factors

often combine to weakened soils physical property to produce severe gullies. The loose

soils aggregate frequently succumb to stress and slumps under highly intensive rainfall

that renders them easily detachable. Some of the soils have the tendency to slake and form

seals under such intense rainstorms thereby resulting in considerable runoff with severe

impact (Nyssen et al., 2004). The soil erodibility factor has also been recognized as

contributing factor to soil erosion hazard in Uyo Metropolis (Udosen 2008). Similarly,

Igwe and Stahr (2004) found that the soil clay content, level of soil organic matter (SOM),

clay dispersion ratio (CDR), mean-weight diameter (MWD) and geometric-mean weight

diameter (GMD) of soil aggregates all influence soil erosion hazards in southern Nigeria.


127

In the event of very aggressive rainfall, the soil inherent properties often combine with the

physical forces of rainfall to detach soil particles rapidly downslope.

Uyo Metropolis (the study area) has experienced obvious environmental problems

in the last few decades. This include improper resource management, destruction of land

for infrastructural development, overgrazing, over cropping of arable lands, strip mining,

deforestation have been identified as the main cause of soil erosion in the region.

However, Udosen (2004) enumerated other causes to include population growth,

population influx and property ownership issues. The effects of human actions in the past

have started attracting concern from several quarters as erosion concavities, astounding

soil wash scenarios, destruction of engineering structures by water erosion and complete

loss of soil fertility are now becoming common features. The gully forms have assumed a

different dimension such that settlements and scarce arable land are threatened. This is

very significant for an area that has the highest population density 500 persons per km2 in

Nigeria. Erosion sieve away vital soil properties that could support meaningful cropping

and other land uses.

2. Aim and Objectives

The study therefore sought to examine soil physical properties as a determinant of

soils susceptibility to gully erosion menace in Uyo metropolis, Akwa Ibom State, Nigeria.

This could be achieved with the following:

1. To identify and map gully sites in the study site

2. To assess the causes of gully erosion

3. To analyse soil physical properties in gully and non-gully sites to determine

susceptibility to gully development

4. Assess materials to mitigate gullies in the gully

3. The Study Area

Uyo is locally located within Akwa Ibom State. It is located at latitude 5o01’N

and longitude 7o56’E. It is bounded on the north by Itu, Ibiono Ibom and Ikono Local

Government Areas, in the East by Uruan Local Government Area, south by Etinan and

Ibesikpo Asutan Local Governments. The 1991 census put the population of Uyo Local

Government Area at 234,615 people spread across the 284.85square kilometres, with a

population density of 324 persons per square kilometres as at 1991. The annual growth

rate is 3% which translates to an estimated population of 776, 280 in 2017. Uyo lies

within the tropical climate zone. It has two major seasons- the wet and dry season. These

climatic conditions impact to the area an equatorial rainforest regime with deep, porous

red soil typified by well-graded sand. Topographically, it is generally undulating lowland,

which is dissected in certain areas of the North-East by gully erosion surfaces. It is

drained mainly by Ikpa River, itself a tributary of Cross River Basin. The mean annual

temperature is 27ᶱC. the relative humidity varies through the year from less than 70 to

over 80%. The mean monthly rainfall is shown in table 1. Fig 2 clearly indicates uni-

modal pattern of monthly rainfall with its peak in July. It also, shows the duration of wet

and dry seasons as nine and three months respectively. The mean annual rainfall is


128

2443mm while the number of rainy days is 130 per annum. The prevailing wind blows

from southwest to the northeast. (Abraham, 2010, Abraham and Giadom, 2014a).

Historically, Uyo has undergone many evolutionary processes of political,

administrative, demographic and economic changes. During the colonial era, Uyo was

made a district headquarters in 1905. With the enactment of the township ordinance of

1917, Uyo was classified as a third-class township. Following the political and

administrative changes in 1905 which culminated into the creation of regional system of

government in Nigeria, Uyo was once again made the headquarters of Uyo federated

county council in the former Eastern region in 1957. Provincial and divisional

administration was later introduced in Eastern Nigeria and Uyo became the administrative

headquarters of Uyo province controlling former divisions of Eket, Opobo, Uyo and

Enyong. In 1976, the local government system was introduced and Uyo became the

headquarters of Uyo Local Government Area; a status it held until 1987, when it was

again up graded to a state capital following the creation of Akwa Ibom State out of the

former Cross River State by Babangida adminstration.

While political and administrative changes were on, spatial changes were

observed. Uyo urban area here refers to such areas which are already built up and those

declared by government as planning areas within Uyo Local Government Area and its

adjoining environs, which sprawl into some neighbouring Local Government Areas. As a

rapidly growing urban center, a local government headquarters and a state capital plus a

regional center, the rate of net migration is positively high.

Fig. 1: Uyo Metropolis Showing Gully and Non-Gully Sites


129

4. Materials and Methods

4.1. Study Sites in Uyo Metropolis

Five gully impacted sites and five non-gully sites provided soil samples that were

used to determine physical properties as a determinant of soil susceptibility to gully

erosion menace. In all the sites, studied the mean slope was 8.6% with annual rainfall of

about 2,214mm distributed over 8-10 months of the year. The area lies within the tropical

rainforest zone of Nigeria (Udosen, 2014). The soils have been classified as ferralitic soil

by Essien and Essen (2012), with characteristic sandy parent materials low in clay content

to bind the soil. Hence, the erosive power frequently experiences provoke the soil to

slumping and sliding with dire consequences on soil physical components (see fig. 1

attached).

4.2 Soil Sample Collection and Laboratory Analysis

For the characterization of the study, randomly collected soil samples within

investigation area was done. Soil auger was used in taking soil samples from five gully

sites and five non-gully sites at both top-soil and sub-soil (0-15cm and 15-30cm

respectively). These soil samples were stored in polythene bags and taken to the

laboratory for analysis for soil physical properties as key indicators of soil susceptibility

to gully development. Particle size distribution analysis was done by the hydrometer

method of Bouyoucos (1962).

Porosity and bulk density were determined using Standard Soil Analysis

Techniques. The Global Positioning System (GPS) device was used to obtain the

coordinate of the gully sites which was used in designing the map of the study area. The

results of the soil samples are presented in table 1-6.

Fig. 2: Gully Site at Etim Umana in Uyo metropolis


130

Fig. 3: Gully site along Ekpri Nsukara Offot, Uyo metropolis

Fig. 4: Anua Gully Site by School of Nursing and Midwifery, Uyo

5. Results and Discussion

Source: Authors Field Work 2018


131


Table 3: Range of Soil Physical Parameters in Gully and Non-gully Locations

at (0-15cm)

Parameters Gully Non-gully

Sand (%) 87.3-97.4 31.7-77.4

Silt (%) 5.7-7.2 3.12-5.32

Clay (%) 3.8-5.7 4.64-7.43

Porosity (%) 60.9-69.8 44.7-61.2

Bulk density (g/cm3) 1.55-1.95 0.92-1.53

Particle density (g/cm3) 2.09-2.86 1.03-2.23


Source: Authors Field Work

2018


132


2018


2018


133

Table 1 to 7 show physical properties of soils in gully and non-gully sites. The

physical properties of the soil at gully locations showed that the sand values ranged from

87.3 to 97.4% with a mean value of 91.80%, standard deviation of 1.64 and a coefficient

of variation of 1.79%. The clay fraction ranged from 3.8 to 5.7% with a mean of 4.52%

and a coefficient of variation of 7.69% percent. Particle size distribution showed little

variability by the coefficient of variation thus, suggesting identical textural classes of the

soils. The dominant particle size was sand fraction which lacked cohesive properties to

bind the soil. The soils were predominantly sandy soils that caused easily succumb when

eroded. This is in consonance with the work of Abraham (2010) in Akwa Ibom State. The

soils are derived from coastal plain sand parent materials which the area represents have

sandy surface soils that is susceptible to erosion. This is because soils dominated by sand

particles fraction enhance susceptibility to leaching and erosion, while those with

dominant clay fraction can impede hydraulic conductivity, infiltration or percolation of

water down the soil layers. The small surface contributes little to the water and nutrient

retention capacity. Lack of cohesion has conspicuously facilitated soil sheering

phenomenon. Thus, soils that are predominantly sandy are prone to leaching and erosion

perturbations. Hence, the proliferation of gully sites in Uyo metropolis. Sandy soil is

generally porous with high sand fraction, a feature which renders them highly prone to

erosion when unprotected from heavy downpours that characterize the area. This

development affects the physical properties of soil and subsequent erosion that affect the

area.

Bulk density values ranged from 1.55 to 1.95 g/cm3 with a mean value of 1.74

g/cm3 and coefficient of variation of 1.57, all obtained as corresponding values from the

area. According to Obi (2000), loamy sand ranges from 1.1 to 1.4 g/cm3 while sandy soil

ranges from 1.6 to 1.84 g/cm3, the values for the present study areas fell within these

ranges. Obi (2000) had earlier stressed that such values were low, indicating that such

soils were in a loose state, leading to high erosion, leaching of valuable nutrients and low


2018


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water retention capacity. These factors clearly indicated that degradation had set in (Lal

1988). Particle density ranged from 2.09 to 2.86 g/cm3 with a coefficient of variation of

4.85 indicating similar values for the four sites. Porosity values ranged from 60.9 to 69.8

with a mean value of 66.82 and coefficient of variation of 2.00 suggesting that the soils

have identical levels of porosity.

On the other hand, the physical properties of the soil at non-gully locations

showed that the sand values ranged from 31.7 to 77.4% with a mean value of 55.08,

standard deviation of 5.71 and a coefficient of variation of 10.37%. The clay fraction

ranged from 4.64 to 7.43 with a mean of 5.80 and a coefficient of variation of 4.48%.

Bulk density values ranged from 0.92 to 1.53 g/cm3 with a mean value of 1.20 g/cm3 and

coefficient of variation of 129%. The result clearly showed that the physical properties

(especially sand contents) in gully locations were significantly higher than the non-gully

locations.

However, it was important to stress that the primary determinant of soil

degradation is the particle size distribution while the other parameters are secondary and

passive factors. The study revealed that soil physical properties play a pivotal role in the

initiation of gully development. However, in gully locations, the physical properties of the

soil were significantly higher compared to non-gully locations. This finding therefore

agrees to similar works on the role of soil physical properties in the development of gully.

Thus, soil with a high proportion of sand, silt, porosity, bulk density and particle density

are prone to gully development than soil that are low in those parameters.

6. Hypothesis

H0 - Soil physical properties were not a determinant to soil

susceptibility to gully development

7. Conclusion and Recommendations

The susceptibility of the soil to gully development is not unconnected to the

nature of the soil physical properties in Uyo metropolis. Hence, the ostensible lack of

vegetation cover, sandy nature of soil, high rainfall regimes, which is a consequence of

the geographical location of Uyo are indeed not isolated with the defenselessness of the

soil to rain wash and gully development. Therefore, it is crucial to adopt an all-inclusive

land use planning to safeguard soil stability. The application of organic manure is also a

reliable way of abridging soil coherence and reduced the susceptibility of the soil to gully.

Farming along the slopes should be totally discouraged to build the soil physical

properties. Afforestation should be taken into consideration. This is because the trees will

help nourish the soil and increase the soil nutrient (thus reducing the sandy nature of the

soil) thereby preventing the phenomenon of gully formation and ensuring a non-threaten

environment for the citizen.

Having discussed the soil physical properties as determinant of soils susceptibility

to gully erosion menace in Uyo Metropolis, Akwa Ibom State, the following

recommendations are hereby made:

1. The soil properties could be sustained with improved farming practices.


135

2. Soil conservation measures adopted in Uyo metropolis should be those of farming

practices that improve cover

3. Sustainable soil management should maintain equilibrium between the ecosystem

and regular anthropogenic influence to improve physical properties.

4. Afforestation should be encouraged; this will provide the soil nutrient thus

reducing the soil physical properties degradation.

5. The aspect of land cover could be provided by reducing the rate of weeding and

bush burning to help prevent unwarranted exposure of soil surface to adverse

effect of weather elements.

6. The kind of afforestation needed should be that which produces intimate multi-

storeyed association of woody species, grasses and creeping legumes. This will

ensure steady cover for the bare soil and offer some kind of protection to the soil

against the highly intensive and aggressive rainfall.

7. Farming along the slopes should be totally discouraged. This activity exposes the

slopes to gully development.

8. The government should make funds available at all levels to combat erosion,

monitor contract and give positive feedback.

8. References

Abdufatai, I. A. Okunlola, I. A., Akande, W. G., Momoh, L. O. and Ibrahim, K. O. (2014).

Review of Gully Erosion in Nigeria: Causes, Impacts and Possible Solutions. Journal

of Geosciences and Geomatics, 2(3): 125-129.

Abraham, C. M. (1998). “Physical Properties of Soils Under Varying Gully Development

Environment, A Case Study of Obotme And Atamong Geography. University of Uyo,

Uyo.

Abraham, C. M. (2001). The Effect of Gully Erosion and Land Degradation on Agricultural

Production in Obotme, Ini Local Government Area of Akwa Ibom State. Research

Report PGD Environmental Education, University of Calabar, Calabar.

Abraham, C. M. (2010). Implications of Gully Development On Agricultural Production In

Akwa Ibom State: An Unpublished Ph.D Thesis, Department of Geography and

Regional Planning, University Of Uyo, Akwa Ibom State, Nigeria.

Abraham, C. M. And Giadom, L. (2014a). Assessment of Devastating Spectacular Gullies

Scenario In Some Agro-Communities In Rural And Urban Fringes In Akwa Ibom

State, Nigeria. A Book of Reading; Environmental Planning and Resource

Development In Niger Delta Region, Nigeria. Edited by Uyanga, J. And Ikurekong, E.

Pp. 51-68

Abraham, C. M., Wilcox, R. I. And Anthony, P. A. (2014b). Assessing Gully Erosion Menace

and Efforts at Amelioration In Itu, Akwa Ibom State, Nigeria. Book of Proceeding;

Environmental Management Association of Nigeria (EMAN), 2014 Annual Conference

– Le Meridian Ibom Hotel and Golf Resort, October 23-25, 2014. Pp. 379-391

Abraham, C. M. And Ewelike, E. A. (2016). Towards Sustaining Reagitated Gully

Environment In Uyo, Metropolis, Akwa Ibom State. Proceeding of The First

International Conference of The Faculty of The Environment Studies (FESIC). Hosted

by The Faculty of Environmental Studies, University of Uyo, Uyo, Nigeria. Pp. 408-

416

Ahmadi, H., 2006. Applied Geomorphology (Water Erosion). Tehran University Press.


136

Bouyoucos, G. J. (1962): Hydrometer Method improved for Making Particle Size Analysis of

Soil-Agron, Journ 54:464-5. Cochran (1997): Statistical Methods

Danladi, et.al. (2014). Socio-economic effect of gully erosion on land use in Gombe

Metropolis, Gombe State, Nigeria. Journal of Geography and Regional Planning, 7(5):

97-105.

Essien O. E., and Essen I. A. (2012). Gully Growth Pattern and Soil Loss Under Rainfall at

Urban Underground Drainage Construction Site, Uyo’ Research Journal of Applied of

Sciences. Engineering and Technology, 4(16), 2616-2625.

Essien O. E., and Okon, E. G. (2011). Rainfall Characteristics, Runoff and Soil Flow on Gully

Morphometric Parameters Growth and Soil Loss un Sand-minded Peri-urban, Uyo,

Nigeria’ Journal of Geology and Mining Research, 3(7), 180-187.

Ezechi, J. (2010). “The Influence of Runoff, Lithology and Water Table on the Dimension and

Rates of Gully Processes in Eastern Nigeria”. International Symposium on Gully

Erosion Under Global Change. Cath University of Lerner, Belgium. April 16-19, Pp.

28-29.

Ezeigwe, P. (2015). Comparative Analysis of the Causes of Gully Erosion in Nkpor and Obosi

in Anambra State of Nigeria, Journal of Environmental and Earth Science

www.iiste.org ISSN 2224-3216 (Paper) ISSN 2225-0948 (Online). Vol. 5, No. 14,

2015.

Fubara, N. (2012). An Assessment and Mapping of Gully Erosion Hazards in Abia State. A

GIS Approach. Journal of Sushtainable Development, 4(5).

Igwe, C. A., & Stahr, K. Water-stable aggregates of flooded inceptisols from southeastern

Nigeria in relation to mineralogy and chemical properties. Australian Journal of Soil

Research (2004). (42), 171-179.

Lal R 1988. Evaluation of erosion perturbation in the tropics. Journal of Soil and Water

Conservation, 40(6): 444- 450.

NEST 1991. Nigerian Threatened Environment. Nigerian Environmental Study Action/Team.

Ibadan, Intec Printers.

Nyssen, J., Poesen, J., Moeyersons, J., Deckers, J., Mitiku, H., Lang, A., (2004). Human

Impact on the environment in the Ethiopian and Eritrean highlands- a State of the Art.

Earth Science Reviews 64(3-4):273-320.

Obi, M. E. (2000). Soil Physics: A Compendium of Lectures. Nsukka: Atlento Publishers.

Ofomata, G. E. K. (2012). Soil erosion. Nigeria in maps, Eastern States, Ethiope Publishing

House, Benin City Nigeria.

Ofomata, G. E. K. (1985). Soil erosion in Southeastern Nigeria: The view of a

Geomorphologist, Inaugural lecture series University of Nigeria Nsukka

Ofomata, G.E.K. (1981). Actual and Potential erosion in Nigeria and measures for control.

Soil Science Society of Nigeria Special Monograph 1, 151-165.

Udosen, C. E. (2004). A Multivariate Approach for Predicting Gully Initiation and

Development in South Eastern Nigeria. Nigeria Journal of Agriculture, Food and

Environment, faculty of Agriculture, University of Uyo 1(1) 40-47

Udosen, C.E. (2008). Rainfall Analysis and Forecasting in Akwa Ibom State. Uyo: Unwana

Graphic Press.

http://www.iiste.org/


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Appendix

Table 1: Physical properties of soil in gully locations (0-15cm)

Location Sand

(%)

Silt

(%)

Clay

(%)

Porosity

(%)

Bulk

Density

(g/cm3)

Particle

density(g/cm3)

Etim

Umana

95.3 5.74 5.04 72.7 1.85 1.94

Anua 97.4 6.94 5.24 67.2 1.70 2.37

Eka Street 91.4 6.62 3.34 63.6 1.53 2.57

Brook

Street

96.3 5.8 5.14 63.8 1.93 2.71

Ekpri

Nsukara

90.1 5.52 3.84 66.6 1.68 2.42


Table 2: Physical properties of soil in gully locations (15-30cm)

Location Sand

(%)

Silt

(%)

Clay

(%)

Porosity

(%)

Bulk

Density

(g/cm3)

Particle

density(g/cm3)

Etim

Umana

88.3 7.0 4.0 60.9 1.63 2.86

Anua 86.2 7.04 3.8 66.4 1.78 2.43

Eka Street 92.3 6.1 5.7 70.0 1.95 2.23

Brook

Street

87.3 5.7 3.9 69.8 1.55 2.09

Ekpri

Nsukara

93.5 7.2 5.2 67.0 1.80 2.38


Table 3: Range, Mean (M), Standard Deviation (SD) and Coefficient of Variation

(CV) of Soil Particles in gully locations

Parameters Range Mean Standard

Deviation (SD)

Coefficient of

Variation

(CV)

Sand (%) 87.3-97.4 91.80 1.64 1.79

Silt (%) 5.7-7.2 6.36 0.27 4.38

Clay (%) 3.8-5.7 4.52 0.35 7.69

Porosity (%) 60.9-69.8 66.82 1.47 2.20

Bulk density (g/cm3) 1.55-1.95 1.74 0.03 1.57

Particle density (g/cm3) 2.09-2.86 2.40 0.12 4.85



138

Table 4: Physical properties of soil in non-gully locations (0-15cm)

Location Sand

(%)

Silt

(%)

Clay

(%)

Porosity

(%)

Bulk

Density

(g/cm3)

Particle

density(g/cm3)

Nkemba

Street

74.3 3.94 6.13 61.2 1.15 1.64

Nelson

Mandela

67.8 5.32 7.43 56.3 1.30 1.92

Osongama 71.3 4.62 4.64 54.2 1.23 1.52

Obio Etoi 66.5 4.7 5.88 58.3 1.53 2.01

Obio Imo 77.4 5.22 5.61 59.3 1.48 2.23


Table 5: Physical properties of soil in non-gully locations (15-30cm)

Location Sand

%)

Silt (%) Clay

(%)

Porosity

(%)

Bulk Density

(g/cm3)

Particle

density(g/cm3)

Nkemba

Street

37.3 3.12 5.3 51.1 0.92 1.11

Nelson

Mandela

44.8 3.22 4.9 46.3 1.32 1.03

Osongama 31.7 4.15 6.6 50.0 1.01 1.28

Obio Etoi 33.4 3.21 5.9 48.2 0.87 1.17

Obio Imo 46.3 4.00 5.6 44.7 1.16 1.62


Table 6: Range, Mean (M), Standard Deviation (SD) and Coefficient of Variation

(CV) of Soil Particles in non-gully locations


Parameters Range Mean Standard Deviation

(SD)

Coefficient of

Variation (CV)

Sand (%) 31.7-77.4 55.08 5.71 10.37

Silt (%) 3.12-5.32 4.15 0.26 6.27

Clay (%) 4.64-7.43 5.80 0.26 4.48

Porosity (%) 44.7-61.2 52.96 1.81 3.42

Bulk density (g/cm3) 0.92-1.53 1.20 1.55 129.17

Particle density (g/cm3) 1.03-2.23 0.07 0.13 185.71

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