Agricultural Economics and Extension Project Topics

Economic Analysis of Soil Conservation Practices Among Crop Farmers

Economic Analysis of Soil Conservation Practices Among Crop Farmers

Economic Analysis of Soil Conservation Practices Among Crop Farmers

Chapter One

Objectives of the Study

The main objective of this study is to identify the traditional soil conservation options available to  farmers  in Ogun state Nigeria and to  investigate the yield implications  i,e. whether the practice is beneficial or otherwise in terms of crop yields.

The study has the following specific objectives.

  1. To identify the major causes of soil erosion on farm lands.
  2. To investigate the extent to which farmers use these conservation and fertility maintenance techniques on their farmer.
  3. To analyse the yield implications, hence the profitability of use of these measures.
  4. To make recommendations on how to encourage the adoption of conservation methods among small-scale formers who may for some reasons not use them.



This chapter reviews the relevant literature related to land degradation and conservation. It provides a brief overview of the general definition of the two concepts: land degradation and soil conservation. The review specifically concerns findings of the factors that have contributed to the process of degradation in the Ogun state parts of the country, their effects and the efforts that have gone into salvaging the situation.

Definitional Concepts.

Land degradation

Land degradation is among the most frequently named global environmental problems because it threatens food production, especially in developing countries. The World Resource Institute estimates that 1.2 billion hectares or 11 percent of the earth’s vegetated surface have been moderately or severely degraded since 1945.16 Biot17 has defined land degradation as an environmental process, which occurs when the ability of the land to produce the goods and/or services people demand from it is declining. In other words, it is the reduction in soil’s productivity that may result from breakdown in soil structure, salinization, water logging, nutrient loss, and pollution from toxic substances. Most of these processes are the result of agricultural activities such as misuse of chemicals and tillage with heavy implements. The thought of soil conditions are what basically comes to mind when the expression “land degradation” is used. It is however important to note that the vegetation growing on the land, such as trees, bushes or grasses are also included.

Among the several overlapping environmental processes involved in land degradation is soil degradation, of which soil erosion is a key contributor.

Soil conservation

In a wide sense, soil conservation includes “all forms of human action to prevent and treat soil degradation”,18 The objective of conservation, according to Sheide,19 is to ensure that the soil functions for long-term use of humans and nature. In the sense used here, conservation aims at protecting the ability of the soil to produce crops and to reduce soil erosion. Soil conservation on agricultural lands includes mechanical and biological measures. Mechanical conservation measures are referred to as “hard” measures because they involve changes of the landscape to slow runoff and guide water safely from fields. Popular methods include contour ridges or bunding for gentle slopes and terraces for steeper slopes. The biological measures rely on vegetative cover for soil protection.

Examples include the use of crop covers like trees, intercropping to reduce the time the soil is bare, and covering the soil with mulch or stubble. Sheng20 also classified soil conservation practices into four categories,

  • Structural or Mechanical erosion practices which is composed of terraces, ditches, windbreaks, earth dams, irrigation dams, controlled land smoothing and land grating.
  • Agronomic practices such as multiple cropping, strip cropping, mulching, cover cropping and crop rotation.
  • Soil management practices like deep ploughing, composting/farm manure, green manuring, and use of fertilizer.
  • Cultivation practices such as minimum/conservation tillage, zero tillage and conventional tillage.

Evidence of degradation

Soil erosion has been described as the most potent degradative process affecting the productivity of agriculture in Nigeria21. However, soil nutrient mining and depletion which starts off productivity diminishing processes leading to the loss of vegetative cover contributes immensely to the exposition of the top soil to erosion.

Various types of soil erosion caused by water namely sheet and gully are common in most parts of the country particularly in the areas where the vegetation has been disturbed in the savannah zones, hilly areas and steep slopes. Annual water erosion is widespread in many parts of Nigeria (Table 2.1).






Method of Data collection

The  study which  was  carried  out  in  4  major villages in Oyo state and Ogun state. Selection of the areas was done purposely to fit into an on-going research study on land degradation and migration, sponsored by the Economic and Social Institute of the Free University of Amsterdam.



Causes of erosion on farming fields.

The first objective of the study is to identify the causes of soil erosion in Ogun state Nigeria. In this section the causes of soil erosion on fields are presented as obtained from interviews using structured questionnaire.

Household heads or representatives were interviewed generally on what they observe as the major factors that contribute/facilitate the process of soil erosion on their individual plots. The result is as presented for the two  s in the Table 4.1 below.




The land use pattern in the study area suggests that the traditional farm household production strategy that has revolved mainly around extensive shifting cultivation with the aim of improving the soil quality is no more. Other husbandry methods, which were able to  cope with the past, are equally ineffective due to  rapid increase in population.

In the face of the low resource/capital base of most farm households, much could still be done with improvement in the use of crop residues, crop rotation and cultivation practices to maintain or improve fertility, reduce run-off and thereby enhance crop yields. Again, improvement on the use of such traditional methods will also mean some form of replacement of the existing over reliance of artificial inputs, the price of which cannot be afforded by the farmer.


One major factor that has exacerbated land degradation and for that matter erosion is the wanton destruction of vegetation through bush burning. Apart from destroying soil nutrients, bush burning destroys small seedlings and big trees thus making it difficult for forests to re-establish themselves thereby exposing the soil to erosion The recurrence of the bush burning problem could be partially attributed to some socio­ cultural practices of the people. The people of Oyo state for example, have an annual practice of sacred bush burning during which the youth hunt game. Other groups in the Ogun state have similar practices. The important issue here is the effect such practices has on the youth rather than the festival itself. They are taught (unconsciously though) to burn and destroy without any sense of guilt81

Virtually all farmers in the study area are aware of the need for soil conservation Four main erosion control techniques and seven fertility maintenance techniques are known and are being practiced by farmers. Of the four anti-erosion techniques, ridging is the common practice in both the Oyo state and Ogun state  s (51 percent and 58 percent respectively). Under normal terrain conditions ridging across the slope is enough to check soil erosion. The next fairly prominent technique is the use of grass strips and crop residue management. Strip cropping is basically used to reinforce ridges.

Household refuse utilization, animal manure, composting, crop residue management, crop rotation, shifting cultivation and fertilizer are the seven fertility maintenance techniques used. Pressures from rapidly rising population have virtually eliminated the age-old system of shifting cultivation. Apart from animal/farmyard manure and household refuse use, the remaining five methods of fertility maintenance are poorly patronized in the study area especially the Oyo state .

Non-use   or    poor    patronage   of  composting, mulching and crop residue management as these fertility maintenance techniques is mainly the result of bush burning which consumes every organic residue on the field. Even though extensive use of stone bunding, as a soil conservation measure is limited to some areas in the Oyo state   (Bongo area), it is worth committing resources into programmes that will Korem A.: Bushfires and Agricultural Development in Nigeria. Nigeria Publishing Corporation, 1985.

encourage its adoption elsewhere. With its high profitability ratio of 9.3 and the more permanent nature of stone bunds, farmers stand to gain eventually.


Prolonged drought certainly tips the balance in favour of desertification, which aggravates the already bad situation created by misuse of the land. Misuse of the land

is however likely to be a result of the high incidence of drought in the area. An ecosystem that is fragile and which is only capable of supporting limited range of crops and livestock for example, leaves the people with no other option than to continue producing with little regard to the carrying capacity of the land.

In view of the above situation, there is an urgent need for an articulate soil conservation policy for the South Western  s of Nigeria. Techniques used for maintaining soil fertility and preventing erosion on continuously cropped lands are already known to farmers. What is required presently is a more participatory approach to programme formulation  and implementation. In other words,  farmers/farming  communities  should  be made  to  feel responsible  for  the sustenance of their  land’s productivity. Enforcement of laws on bush fires should be entrusted in community leadership with strong support from government.

Control of water erosion with the use of contour ploughing and maintenance of field cover is vital. Farmers should be given the necessary institutional support (a reformed extension effort) in the area of education on effective conservation. Conservation practices involving trees species, should be included in Pastureland development should also feature on agriculture as well as financial assistance extension packages to formers. prominently in future government policies (various forms of subsidy) to farmers.


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