ECONOMIC STUDY OF FARMLAND EROSION CONTROL PRACTICES IN ENUGU STATE, NIGERIA
An economic analysis of farmland erosion control practices was conducted in Enugu State, southeastern Nigeria. The study aimed at identifying and describing the erosion control practices applied by the farmers, determining the net-benefit of erosion control practices, determining the socio-economic factors affecting the farmers’ use of a particular erosion control practice and identifying from the farmers perspective the possible causes and extent of cause of erosion on the farmland as well as making recommendations based on the findings. An interview schedule and structured questionnaire were used to elicit primary data from 168 farmers, randomly selected from the three agricultural zones of the state. Analysis of the data were done using multinomial logit model, partial budget analysis Duncan’s Multiple range test and descriptive statistics. Four erosion control practices were used by the farmers: Multiple cropping, as indicated by 41% of the respondents, Construction of Bonds, 20%, Ridging across the slope, 18% and Cover cropping, as indicated by 21% of the respondents. The Partial budget analysis showed the net-benefits of each of these erosion control practice as N393, 953.88k for Multiple cropping, N26, 115.30k for Construction of Bonds, N33, 741.66k for Ridging Across the slope and N891.10k for Cover cropping. 7.36 (Multiple cropping), 1.59 (Construction of bonds), 1.14 (Ridging across the slope) and 1.10 (Cover cropping) were shown as the profitability index for the erosion control practices. Duncan’s comparison test showed that there was statistically significant difference in the means of net-benefits of erosion control practices at 5%. The Multinomial logit Regression analysis indicated a seemingly low explanatory powers of the factor as reflected by Pseudo- R2 of 0.2449, but this is not uncommon in cross sectional analysis. The overall goodness of fit as reflected by prob>Chi2 was however good (<0.0000). The age of the farmers negatively and significantly affected the farmer's probability of using Cover cropping at 1% level of probability, all in comparism with Construction of bonds. Household size positively and significantly affected the farmers probability of using Multiple cropping and making ridges across the slope at 1% probability level. The Likert rating scale technique showed six very serious causes of erosion on the farmlands. These were Rainwater (mean = 2.42), Deforestation (mean = 2.26), Soil type (mean =2.49), Slope of the farm (mean =2.37), Poor road construction (mean =2.35), Indiscrimate house construction (mean =2.16). It also indicates two serious causes of erosion which include; Population density (mean =1.99) and Poor farming system (mean =2.01). Others such as Quarrying of sand (mean =1.64), Crops that attracts human traffic (mean =1.42), gods (mean =1.16), Overgrazing (mean =1.74), and Cattle hooves were shown as not serious causes of erosion by the Likert rating.
It is therefore recommended that government should encourage farmers with incentives to cope with the challenges of erosion for a sustainable Agriculture and Environment.
TABLE OF CONTENT
Table of content
1.0 INTRODUCTION - - - - - - - 1
1.1 Background of the Study - - - - - - - 1
1.2 Statement of the Problem - - - - - - - 5
1.3 Objectives of the Study - - - - - - - 7
1.4 Research Hypotheses - - - - - - - 7
1.5 Significance of the study - - - - - - - 7
2.0 Literature Review - - - - - - - - 9
2.1 Concept of soil erosion - - - - - - - 9
2.2 History of soil erosion - - - - - - - 12
2.3 Mechanism of soil erosion - - - - - - 14
2.4 Economics of soil erosion - - - - - - - 17
2.5 Factors responsible for erosion in Enugu state - - - - 20
2.6 Classification of erosion - - - - - - - 24
2.7 Erosion control - - - - - - - 30
2.8 Problems and effects of erosion - - - - - - 35
2.9 Documentation of erosion site in Enugu State - - - - 40
2.10 Review of existing erosion control practices - - - - 42
2.11 Theoretical framework - - - - - - - 47
2.12 Analytical framework - - - - - - - 54
2.12.1 Multinomial logit model - - - - - - 54
2.12.2 Partial budgeting - - - - - - - 57
2.12.3 Duncan’s multiple-range test - - - - - - 60
3.0 Methodology - - - - - - - - 61
3.1 The Study Area - - - - - - - - 61
3.2 Sampling Procedure - - - - - - - 62
3.3 Data Collection - - - - - - - - 63
3.4 Data Analysis - - - - - - - - 63
3.5 Test of Hypothesis - - - - - - - 63
3. 6 Model Specification - - - - - - - 64
3.6.1 Multinomial Logit Model - - - - - - 64
3.6.2 Partial Budget Analysis - - - - - - - 66
3.6.3 Duncan’s Multiple Range Test - - - - - - 68
3.6.4 Likert rating scale technique - - - - - - 69
3.6.5 Profitability index - - - - - - - 69
4.0 Results and Discussion - - - - - - - 70
4.1 The erosion control practices applied by farmers in the area - - 70
4.1.2 Combination of erosion control practices applied by farmers - - - 71
4.1.3 Description of Farmland Erosion Control practices applied by Farmers- 72
4.2 Costs and returns for the erosion control practice - - - 74
4.2.1 Multiple Cropping Partial Budget - - - - - 74
4.2.2. Construction of Bonds - - - - - - - 75
4.2.3. Ridging Across the Slope - - - - - - 76
4.2.4 Cover Cropping - - - - - - - - 77
4.2.5 Duncan’s Multiple Range Test - - - - - - 79
4.3 Socioeconomic Factors Affecting Farmer’s use of Particular Erosion Control 80
4.4 Possible Causes of Erosion on the Farmland from the Farmers Perspective 84
4.4.2 Causes and extent of cause of erosion as perceived by the farmers - 87
5.0 Summary, Conclusion and Recommendations - - - - 90
5.1 Summary - - - - - - - - - 90
5.2 Conclusion - - - - - - - - 92
5.3 Recommendations - - - - - - - - 93
REFERENCES - -- - - - - - - 95
APPENDIX - - - - - - - - - 115
1.1 Background of the Study
A dramatic acceleration in population growth has taken place in sub-Saharan Africa since the 1960s (World Bank, 2006). The increasing demand to feed this growing population has lead to resource use intensification (Junge, Birte, Abaidoo. Chikoye ,D. Alabi ,T. and Stahrand Karl,(2006). and Non- adaptable land use practices which lead to soil degradation (Hudson, 1995). In sub-Saharan Africa, soil degradation has already become the most critical environmental problem (Mbagwu,Lal, and Scott,(1984) Eswaran ,,Lal and Reich,( 2001). Soil erosion is one manifestation of soil degrading processes that results in reduced soil quality and productivity (Akamigbo, 2001, Morgan, 1995, Lal, 2001). There is an urgent need to combat the accelerating trend of soil degradation, to maintain soil productivity and to contribute to the food security of current and future generations (UNEP, 1997).
Ecological disasters rank high among factors which encourage inefficient utilization of resources in Nigeria and limit the country’s development potential. They occur in various forms but typically include droughts, soil and wind erosion, flooding, oil pollution and bush fires. Soil erosion is one of the most important physical problems affecting our development in this part of the world today. Apart from the fact that it constitutes a menace to the environment and its destruction of our infrastructures-high ways, big structures etc, it creates a major problem in our agricultural soils, thereby interfering seriously with the mass food production campaign. We cannot afford to over-look these problems created on our soils by soil erosion because there is no real evidence that we may some day detach our lives from the soils. It is the soils that sustain us because soils are the foundation of our worldly goods-a basic wealth upon which our existence as inhabitants of the earth depends (Akamigbo 1987).
The web definition of erosion says it is the wearing away of the earth’s surface by running water, wind, ice, or other geological agents, processes, including weathering, dissolution. Akamigbo (1988) defined erosion as a systematic removal of soil, including plant nutrients, from the land surface by the various agents of denudation. According Ofomata (1988), soil erosion can be regarded as merely a geomorphologic process, whereby the surface layer of weathering rock is loosened and carried away by wind or running water and a lower horizon in the soil is exposed.
Soil erosion occurs in several parts of Nigeria under different geological, climatic, and soil conditions. The degree of occurrence varies considerably from one part of the country to the other. Soil erosion occurs all over southeastern Nigeria. The incidence of soil erosion in southeastern Nigeria especially Enugu state is not new, as it has formed a subject for serious consideration since the beginning of this century. For instance, the Udi forest Reserve was created in 1922, followed by an Anti-Erosion plantation, also at Udi, in 1928 (Sykes, 1940), all aimed at combating the nefarious effects of soil erosion as highlighted by the general review of the state of soil erosion in Nigeria by late Sir. Dudley stamp in 1938. Stamp’s review was followed by the special study of the phenomenon by Grove (1951) in part of former Eastern Nigeria as well as by Ofomata in some greater detail in parts of southeastern Nigeria (Ofomata, 1964, 1965, 1966, 1967, 1973, 1980, 1981a, 1981b, 1981c, 1982, 1984, 1985a, 1985b and Stone, 1996). Soil erosion is a major limitation to sustainable production in most farmland of Africa (Lal, 1995) in general and southeastern Nigeria (Enugu State) in particular. It ranks as one of the most serious problems on agricultural lands, threatening large populations with starvation (Oti 2002). Studies have shown that soil erosions is by far the most severe hazard affecting the lands of Nigeria, ravaging all of its bio-climatic regions as rill, sheet, and gully erosion (Ofomata 1964,1980,1982,1984a, and b, Ologe, 1971: Oganuga 1978, , Anon, 1988). Soil erosion causes the loss of a tremendous amount of valuable soil, (Kio and Okorie (1986). It has been estimated that about 30 million tones of soil are lost annually throughout the country with the eastern states losing over 15million tones, (Onyeagocha, 1980, Okorie and Adeola, 1985). The depletion of agricultural land resources occurs through different forms of land degradation namely, leaching of nutrient, erosion by water which has led to devastating gullies in some parts of the country especially southeast, drought and wind erosion resulting in desert encroachment in the northern parts of the country and wastage of land by flood and coastal erosion, (Akamigbo, 2006). As soil becomes depleted by water erosion, people attempt to move to other more productive land. Eventually, when there is no more land available they are forced to adapt themselves to smaller amounts of food which require harder work to grow. This condition lead to malnutrition and hopelessness. (FAO 1965). Erosion, as an environmental hazard has numerous adverse economic effects on the lives and livelihood of people. Generally it results in a degradation of the environment, and reduction in land area available for habitation, agriculture, industry, recreation, road construction, as well as loss of soil fertility. Furthermore, erosion also leads to pollution and blocking of waterways, loss and destruction of social centers, and social amenities. (Ezebube, 1989 and Akamigbo, 1999). Soil erosion also leads to pollution and blocking of waterways, loss and destruction of social complex process that depends on soil properties, ground slope, vegetation, and rainfall amount and intensity (David, 2007).
The major environmental cause of soil erosion in southern Nigeria is rainfall with the mean annual rainfall reaching about 3000mm in some parts and with rainstorms often of long duration and intensities which may be up to 200mm-1, it would be expected that the erosivity factor plays a dominant role in the soil loss problem (Obi and Asiegbu, 1980). Controlling erosion on productive land must usually be done while growing crop. Therefore many control measures are closely related to ordinary methods of agriculture.
The common ones are land use, cropping systems, cover crops, fertilizers and manures, ridging across the slope, construction of bonds, grassing of water ways, hedge-row planting / vetiver grass and tillage practices (FAO, 1965., Akamigbo, 1988, 1998., Ofomata, 1988., Chude, 2005., Lal 1995., ENADEP, 2007). Management of soil for water and wind erosion control is based on sensible soil conservation practices. The majority of these practices are recognized components of good soil, crop, and water management for effective erosion control. It is important to maintain good soil structure, protect the soil surface by adequate crop and residue cover, and use special structural erosion control practices where necessary. These factors often control both water and wind erosion. Not all erosion control practices will fit into every farm management scheme. However, each erosion problem can be remedied by choosing one or more of the remedial practices appropriate to the problem. (Stone, 1996). Of all types of erosion the most pernicious and serious on the farmland in the southeast is the sheet erosion. It causes the gradual but significant losses of soil particles and mineral nutrients which are carried away in surface run-off during rainfall or blown away as loose particles by strong winds in drier areas. The activities of man and other land animals, which destroy vegetation cover, predispose the soil to accelerated sheet erosion. For instant, the hooves of cattle in any fragile soil environment pulverize the soil as they move and render the soil susceptible to both wind and water erosion, (Akamigbo, 2006).
1.2 Problem Statement
Farm land erosion poses a very serious set back to farmers in Enugu state and the extent of the spread and damage have reached an alarming proportion that if efforts are not intensified to remedy the ugly situation, it could cause untold hardship and put the communities in a state of jeopardy. It has been estimated that available arable lands in the states of the southeastern Nigeria have been reduced by 50% as a result of erosion (Braide, 1982). Erosion leads to the pollution and destruction of the environment. Rural water supply from streams is also constantly being polluted by heavy sediment load, thereby adding health hazard to the problem of damage to infrastructure (Akamigbo, 1999). Some of the most ravaging erosion related environmental hazards are found in many parts of the southeast, especially Anambra, Enugu and Imo states (Ofomata, 1985, Akamigbo, 1988 and Ogbukagu, 1986). Many farmlands from which majority of the households earn their livelihood are especially affected; a situation which has led to thigh population pressure on the available land (Onuora, 1985, Ezebube, 1989, and Akamigbo 1999). This condition according to them have inflicted great losses in the production potentials, crop land, crop quality, biodiversity, genetic resources as well as excessive field fragmentations.
The economic cost of erosion is very difficult to quantify, but it is definitely very large, Huge sums of money are spent each year repairing damage caused by erosion or reinforcing existing structures and land against erosion, (Akamigbo, 1999).
Money that should be used by rural farmers in Enugu state for solving their family problems is spent on erosion control.
Erosion control is usually expensive and many efforts have been made by successive governments to control erosion in southeastern Nigeria but not much success have been achieved. This could be attributed to lack of proper understanding of the techniques involved in handling erosion control. Agro-engineering findings indicate that farmers in the rural southeastern Nigeria apply many techniques to conserve soil, control erosion and prevent soil degradation. (Onuoha, 1985 and Ofomata 1982). Young (1989) states that the costs or labour requirements of physical erosion control works necessary to control run-off by such means as bunds and terraces were commonly found to be expensive. “Conservation farming” or “integrated land use”, the emerging farming systems approach to environmental conservation, has been practiced by Nigerian farmers for a long time (Okoye, 2001).
Young (1989) advocated the use of simple methods of erosion control such as mulching, bunding, and cover cropping, which are within the capacity of the farmers to establish and maintain, and endorses external support for sound traditional farming practices. Despite the awareness of these traditional techniques and management actions of the local farmers to control erosion and protect the environment, they have remained largely under studied, unexplored and neglected especially with regards to the economic evaluation of these indigenous techniques. (Reiji 1990, Eboh 1991).
Although, Utazi (2002) carried out an economic study of farmland erosion control practices in Imo state where he identified the different erosion control practices used by farmers in the area and determined the cost benefits of erosion control practices, he failed
to describe from the farmers perspective the possible causes of erosion on the farmland as well as determining the socioeconomic factors affecting the farmers use of a particular erosion control practice. Another missing value is the difference in location of the study.
This study therefore aims at addressing these missing links in Enugu state.
1.3 Objectives of the Study
The broad objective of this study was to conduct an economic analysis of farmland erosion control practices in Enugu State. The specific objectives are to;
i. identify and describe the erosion control practices (or combination of practices) applied by farmers in the area.
ii. determine the net benefit of erosion control practices.
iii. determine the socioeconomic factors affecting the farmer’s use of a particular erosion control practice.
iv. identify from the farmer’s perspective the possible causes of erosion and extent of cause on the farmland.
In line with the specific objective this research was guided by the following null hypotheses;
1. There is no relationship between the socioeconomic characteristics of the farmers and the type of erosion control practices used.
2. There is no significant difference between economic benefit of different erosion control practices by the farmers.
1.5 Justification of the Study
The study will provide information to farmers on the net benefits of farmland erosion control practices for increased crop productivity and food security. Measures aimed at controlling farmland erosion will to a large extent save soil fertility, economic trees and crops and farmland from being devastated. The knowledge of the economics of erosion control measures will guide the policy makers in quantifying the control practices for future planning.
On the other hand, information on the economic analysis of farm land erosion control practice will equip the Environmental Protection Agency (EPA),in formulating appropriate environmental related policies in order to ensure environmental sustainability. Achieving certain standards of erosion control, will provide information about the value given to land in the market to erosion control, what will help investment decision.
Finally, other researchers that are interested in searching for solutions of the devastating effect of erosion will be assisted with the information that will be provided in the study. It will invariably provide information on how best to increase the farm land value in other to consequently increase its productivity and alleviate poverty..