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  Do tree shelter-belts have the relative advantage to convince farmers to grow them: an empirical example from the Gezira Agricultural Scheme, Sudan. 

ٍSiddig El Tayeb Muneer
Department of Agricultural Extension and Rural Sociology
Faculty of Food and Agricultural Sciences
King Saud University

 o tree shelter-belts have the relative advantage to convince farmers to grow them: an empirical example from the Gezira Agricultural Scheme, Sudan. 

Abstract:

One of the major environmental problems facing the arid, semi-arid and dry sub-humid areas of the world and causing substantial reduction in agricultural production and agricultural income of many farmers is desertification. In Sudan desertification is considered one of the main causes of low crop productivity in many areas, among which is northwest part of the Gezira Agricultural Scheme. In 1991 the scheme administration started establishing a tree shelter–belt to protect the entire scheme from desertification, starting with the most affected areas (like Abu Gota and Bagigah blocks) in the North West part of the scheme. This study is intended to examine the effect of this tree shelter-belt in mitigating the negative impacts of desertification.

Abu Gota block of the Gezira Agricultural Scheme which is one of the most affected areas by desertification and where the tree shelter-belt is established was chosen as the study area. The data was collected through personal interviews with a stratified random sample of 300 farmers. Chi-square test is used to analyze the data.  

The study results indicates that farmers whose farms are located close to the tree shelter-belt were less affected by desertification and consequently they obtained high agricultural income compared to those whose farms are located far from the tree shelter-belt and they tend not to resort to poverty coping strategies such as hiring their family labor to others and pulling their children out of school.  

Introduction

Agriculture plays a vital role in the economy of many countries. In such countries a large portion of the population earn their income from utilizing agricultural natural resources such as agricultural land, irrigation water, forests, grazing lands etc… and in many countries these resources are increasingly overexploited and problems like rural poverty, food insecurity and rural-urban migration are encountered. The poor in the rural areas of the developing countries are often forced by circumstances and institutions beyond their control to destroy the few resources available to them (de Boom, 1990; FAO, 1992). By doing so, they are ultimately trapped in vicious circle of lack of food and fuel on one hand, and deterioration of the environments producing these necessities on the other hand. Therefore, many researchers associate poverty and environmental degradation and argue that the relationship between them is direct and symmetrical; i.e. poverty induces environmental degradation and environmental degradation deepens poverty (Grainger, 1982; Nicholson, 1986; de boom, 1990; FAO, 1994). Furthermore, and because of the fact that the poor constitute the majority of the adopters’ category labeled as laggards who are not expected to adopt any environmental conservation or rehabilitation innovation (Rogers, 1993), reinforces the vicious spiral of poverty and environmental degradation and makes it difficult to be halted. In the case of environmental problems related to desertification and deforestation, the problem is even aggravated more by the negative attitude usually some farmers have towards the presence of trees in their farms. Farmers usually believe that trees make less land available for planting crops and harbor insects and birds that damage their crops (Clarke and Thaman, 2006). 
One of the major environmental problems facing the arid, semi-arid and dry sub-humid areas of the world and closely related to poverty is desertification. Desertification is caused by various factors including climatic changes and human activities and, it is accompanied by a reduction in the natural potential of the land and a decrease in surface and ground water resources and has negative repercussions on the living conditions and economic development in the affected areas. Worldwide desertification affects about two thirds of the countries of the world and one third of the earth’s land surface (about 4500 million hectares) which is inhabitant by approximately one billion people (FAO, 2006). One of the main important causes of desertification is deforestation. Deforestation means the loss of trees with its many functions. It is attributed to factors such as cleaning of land for horizontal agricultural expansion and excessive trees cutting for fuel-wood consumption. The most desertification affected regions are the Sudano-Sahelian regions followed by Africa south of the Sudano-Sahelian region and South Asia. Sudan is one of the Sudano-Sahelian regions that are severely affected by desertification. Bayoumi (1984) reported that in Sudan human activities were responsible for the loss of 20 million metric tons of wood annually. Furthermore, it has been observed that severe cutting of national forests east of the White Nile allowed the encroaching sand to reach the Gezira scheme and clogged the canals and covered the villages in the affected areas (FAO, 1986). In the past these forests acted as a barrier to the moving sands.
Problem Statement
The Gezira Scheme is the largest agricultural scheme in Sudan with an area of 2.1 million feddans[1]. It is irrigated by gravity irrigation from Sennar Dam. It provides livelihood for more than 100,000 farmers and families. Before mid 1970s the scheme was adopting a mono – culture farming system where only cotton was grown. After then, a diversified farming system is adopted and the farmers are allowed to produce wheat, sorghum, groundnut and vegetables in addition to cotton. The scheme contributes significantly to the country economy. It produces about 80%, 30%, 60%, 60% and 20 % of the country total production of long stable cotton, medium stable cotton, groundnut, wheat and sorghum respectively; in addition to considerable amounts of vegetables, fruits and milk (Sudan Gezira Board, 1992).
One of the main problems causing low crop productivity in the scheme, particularly in the northwest boundaries, is desertification. Consequently, in 1967 the scheme administration (Sudan Gezira Board) had established a protective tree shelter - belt, the Tahamied shelter - belt, which is believed to play an effective role in mitigating desertification negative impacts. During recent years this belt is not managed properly (i.e. not properly irrigated and not protected against cutting and grazing). This has led to appearance of large gaps through which moving sands entered the fields, clogged irrigation canals and made irrigated agriculture difficult or impossible in some cases (FAO, 1986; Forestry Administration, 1987). A study conducted by the University of Gezira (1987) to examine the negative impacts of desertification in the Gezira Scheme indicated that sand encroachment has resulted in irrigation problems such as sedimentation of canals and coverage of fields with sand which led to reduction in the cropped area. Consequently, farmers in severely affected areas are unable to grow some crops that are grown during the dry season and have high water requirements and even the grown crops neither get the required number of irrigations, nor the optimum amount of water per irrigation. Furthermore, sand encroachment on the fields made gravity irrigation difficult and the water requirements of the different crops had increased due to the increased evapotranspiration. Moreover, soil fertility is expected to change depending on the type of the added soil. Plants’ height and leaves were also affected by blowing winds. All this has resulted in low crop productivity and agricultural income which in turn caused migration, particularly of young people, from the affected areas (Echholm, 1984; United Nations Environment Program, 1986).
Although there is no accurate statistics about the size of the area affected by desertification in the Gezira Agricultural Scheme, but there is no doubt that it is increasing annually. Accordingly, in 1991 the scheme administration started establishing a new tree shelter–belt to protect the entire scheme from desertification, starting with the most affected areas (like Abu Gota and Bagigah blocks) in the North West part of the scheme (Forestry Administration, 1995).
Thus, this study aims at examining the relative advantage of this tree shelter-belt in terms of its role in mitigating desertification effect in Abu Gota block and how it could be used to encourage farmers’ participation in the forestation efforts.
Objectives of the study:
The study aims at:
1.     
Examining the effect of the tree shelter-belt on the total cropped area by each farmer.
2.     
Assessing the effect of the tree shelter-belt on the farmer’s total agricultural income.
3.     
Assessing the effect of the tree shelter-belt on agricultural productivity.
4.     
Exploring the role of the tree shelter-belt in mitigating desertification effects. 
Methods:  

One of the most affected areas by desertification in the northwest part of the Gezeira Agricultural Scheme and where the new tree shelter-belt is established   (Abu Gota block) was chosen as the study area. The total area of this block is 20161 feddans and it is cultivated by 1305 farmers who represent the study population.  About one third of the farmers in the study area are near the tree shelter-belt which is believed to mitigate desertification effects particularly with regard to clogging of irrigation canals and consequently availability of irrigation water. Accordingly, the farmers in the study area were divided into two categories based on how close their farms are to the tree shelter-belt and the extent to which their farms were affected by desertification. About one third of the farmers were identified as near the tree shelter-belt and less affected by desertification and two thirds as away from the tree shelter-belt and more affected by desertification.
A random sample of 100 farmers was selected from the farmers’ group identified as near the tree shelter-belt and a random sample of 200 farmers was selected from the farmers’ group identified as away from the tree shelter-belt. Thus, a stratified weighted random sample of 300 farmers was selected. Chi-square test is used to examine the differences between the two groups of farmers in terms of the extent to which they were affected by desertification and the strategies they used to cope with those effects.
Measurement of some of the study variables:
1.     
Gross farm income: Was measured by the total monetary value of all the crops grown by each farmer.
2.     
Farm productivity: was measured by gross farm income per feddan and was obtained by dividing the total gross farm income by the total area of all crops grown.
3.     
Cropped area: Was measured by the total area of all crops grown by each farmer in feddans.
4.     
Number of days the family members worked as hired laborers: Was measured by the total number of days the family members (whom their primary occupation is agriculture) worked as hired laborers for others in their village or outside their village. 
5. Average school drop-out rate: Was measured by the number of the household members who are in the school age (6 – 22 years) and not attending school divided by the total number of the household members who are in the school age (6 -22 years). 
Literature review
To understand the relationship between poverty and environmental degradation (usually referred to as the vicious circle), it is useful to distinguish between two types of poverty: conjunctional poverty and structural poverty (Tigani, 1990). Conjunctional poverty occurs when people loose their wealth and assets during times of natural disasters and environmental problems such as droughts and floods or man made disasters such as wars. As a result of conjunctional poverty that is induced by natural environmental degradation, people will either over-exploit and misuse the remaining natural resources or migrate to other areas (usually big cities) where they cause pressure on the already limited services and deteriorating environment. Thus, by impoverishing the natural potential of ecosystems, environmental problems such as desertification, reduce agricultural yield and make it less predictable and render rural population in the affected areas vulnerable to food shortages, the vagaries of weather and natural disasters. In order to get their most urgent needs people will develop survival strategies which in turn aggravate environmental problems such as desertification and impede development. The other type of poverty is structural poverty which usually results from structural adjustment and economic reform policies and it affects certain segments of the population because of their personal characteristics (e. g. small farmers, women, female-headed households, wage workers etc…). Again, and in order to get their basic needs and necessities people who are affected by structural poverty will be engaged in activities that will lead to environmental degradation (de Boom, 1990).  Thus, while conjunctional poverty is the consequence of environmental degradation, structural poverty is the cause of environmental degradation.
One of the main environmental problems facing the world and closely related to poverty, particularly in rural areas, is desertification. Desertification as defined in Chapter 12 of Agenda 21 and in the International Convention on Desertification is the degradation of the land in arid, semi-arid, and dry sub-humid areas resulting from various factors, including climatic variations and human activities (Koohafkan, 2006). It manifests itself initially in destruction of soil fertility, declining crop yield, a change in the quality and quantity and diversity of vegetation where perennial trees and grasses decrease, palatable and nutritious plants are replaced by less valuable species, or even toxic shrubs (Echholm,1976).   Consequently, it is accompanied by a reduction in the natural potential of the land and a decrease in surface and ground water. Thus, it leads to a reduction of plant biomass and land carrying capacity to support crops and livestock and has negative repercussions on the living conditions and economic development in the affected areas (United Nations, 1977).
Different investigators had reported different causes of desertification in different parts of the world (Mabbutt, 1984; Grainger, 1990; Noordwilk, 1984; Ibrahim, 1978). Nevertheless, the most important and common causes of desertification include: land clearance and over-cultivation, which refers to the expansion in cropping (both rain-fed and irrigated) and shortening of fallow periods. It occurs when farmers try to use land more intensively regardless of its natural fertility and without adding fertilizers or allowing it to generate its fertility naturally. Therefore, over-cultivation reduces the soil fertility, damages its structure and exposes it to erosion. The second cause is over-grazing, which occurs when the number of livestock is increased beyond the carrying capacity of the range-land, leading to the destruction of vegetation and the compaction and erosion of the soil. In Sudan over-grazing is caused by the enormous increase in livestock, deterioration of range-land, and settlement of nomads so as to be provided with improved services and development of water points (de Boom, 1990). A third cause of desertification is deforestation. Natural and cultivated vegetation plays an essential role in protecting the soil, particularly trees and bushes which due to their long life and their capacity to develop powerful root systems, guarantee effective protection against soil degradation (FAO, 2006). Therefore, deforestation, which means disappearance of trees with its many functions, increases the vulnerability of the land to desertification considerably. Deforestation is attributed to factors such as cleaning of land for horizontal agricultural expansion and excessive trees cutting for fuel-wood consumption. Clarke and Thaman (2006) reported that deforestation has led to severe erosion in the pacific islands (Wallis and Futuna, the Cook Islands, French Polynesia) where most of the indigenous forest has been removed , leaving degraded lands and grasslands no longer suitable for agriculture and they argued that Pacific Islanders, like people everywhere, prospered by disturbing the natural order. Bayoumi (1984) reported that in Sudan human activities were responsible for the loss of 20 million metric tons of wood annually. Furthermore, it has been observed that severe cutting of national forests east of the White Nile allowed the encroaching sand to reach the Gezira scheme and clogged the canals and covered the villages in the affected areas (FAO, 1986). In the past these forests acted as a barrier to the moving sands. A fourth factor that contributed to desertification is drought. Although, there is no conclusive consensus about the relationship between drought and desertification, yet, there is no doubt that drought makes the impacts of desertification, which are reflected in crop failure, livestock mortality etc.., more felt by those living in the affected areas (Grainger, 1990; Nicholson, 1986). 
Bellefontaine et al. (2000) indicated that over the past few decades several of desertification causes have been at work; fallow periods are increasingly being curtailed, soil is becoming ever less fertile, land clearance for agricultural purposes is being stepped up, overgrazing is increasing and fuel-wood needs are constantly rising. Thus desertification is expected to be a real threat to livelihood of many people worldwide. Consequently, and because of it’s devastating effects it has been widely accepted that combating desertification must form an integral part of the socioeconomic development programs for the affected areas and it requires full participation of the local people (FAO, 2006). Therefore, participatory forest management as a concept and a goal has become widely accepted for the management of forest (FAO, 1998; Gilmour, 1995). Participatory forest management is concerned with managing the forest as a complex valuable natural resource system that has several crucial functions and not only as a source of wood. Participation of the local people is considered one of the principles of participatory sustainable forest management (FAO, 1998).  
For farmers to adopt any new practice, such as participation in forest management and afforestation programs, they have to perceive that it has a relative advantage that is beneficial to them. Innovation’s relative advantage is usually expressed in economic profitability, in status giving, or in other ways. Diffusion scholars have found relative advantage to be one of the best predictors of an innovation’s rate of adoption and for some innovations and for some adopters, economic aspects of relative advantage (profitability) may be the most important single predictor of rate of adoption (Rogers, 1993). In some studies it was possible to explain about 30 percent of the variation in rate of adoption on the basis of economic relative advantage (Griliches, 1957; Dixon, 1980). Therefore, for farmers to participate effectively in afforestation programs they have be persuaded that these trees and forests are beneficial to them in one way or another (i.e they have a relative advantage). 
R
esults and discussion:
Desertification has negatively affected agriculture and the living conditions of people in the northern parts of Gezira Agricultural Scheme in different ways. By clogging irrigation canals it has made less irrigation water available and many farmers can’t make use of their farms because of shortage of irrigation water. Moreover, the grown crops can neither get the recommended number of irrigation, nor the required amount of water per irrigation. Furthermore, desertification covers the agricultural land with sand which lowers land productivity and increases the cost of land preparation and consequently agriculture in the affected areas has become less profitable. Consequently, farmers have abandoned agriculture as their main occupation and start to work as agricultural laborers for other farmers in other villages that are not affected by desertification and some of them even migrate to cities. The tree shelter-belt is expected to mitigate these negative impacts of desertification.

Table (1) reflects the effect of tree shelter-belt on the total area cultivated by the farmers. It is clear that the majority (70%) of the farmers whose farms are located far from the tree shelter-belt did not cultivate large or even medium areas of their farms. Respondents attributed this mainly to lack of enough irrigation water due to irrigation canals being clogged by sand. A second reason indicated by the respondents for cultivating small area is the farmers’ perception that agriculture is no longer a profitable occupation because of the high cost of production and the decrease of their farm productivity caused by desertification. On the other hand, about two thirds (63%) of the farmers whose farms are close to the tree shelter-belt cultivated medium size area and about one third (31%) of them cultivated large areas and most of them indicated that desertification effect on their farms with regard to availability of irrigation water is very minor. Chi-square test has revealed that the difference between the farmers whose farms were identified as close to the tree shelter-belt and those whose farms were identified as far from it regarding the size of the total cultivated area is statistically significant at (< 0.001) level of significance. This suggests a very strong association between the size of the total cultivated area and the location of the farm with regard to the tree shelter-belt. This is a very clear relative advantage of the tree shelter-belt that should be used and emphasized by the agricultural extension service in Gezira Agricultural Scheme to increase farmers, awareness, even in areas not affected by desertification, about the role of trees and forests in controlling and mitigating desertification effects, so as to motivate and persuade them to actively participate in the afforestation  programs implemented by the Scheme administration to establish a tree shelter-belt around the whole Scheme. 
Table 1. Tree shelter-belt effect on total cultivated area of all crops

Total cultivated area

(All crops)

Location of the farm from the tree shelter belt

Total

Far

close

Small cultivated area

(Less than 4 feddans)

140

6

146

Medium cultivated area

(4 – less than 8 feddans)

53

63

116

Large cultivated area

(8 feddans or more)

7

31

38

Total

200

100

300

Chi-square = 118.88 (P < 0.001) 

In addition to it effect on the total area cultivated by each farmer, the tree shelter-belt is expected to have positive effect on land productivity as the soil fertility will be less decreased by desertification and the crops will get the required number of irrigations and the proper amount of water per irrigation. The results presented in table (2) support this thesis, where 30 percent of the farmers whose farms are located away from the tree shelter-belt got low productivity while no one of those whose farms are close to the tree shelter-belt obtained low productivity. On the other hand, the majority (70%) of the farmers whose farms are close to the tree shelter-belt obtained high productivity compared to only one fourth of the farmers whose farms are located far from the tree shelter-belt who obtained high productivity. The negative association between the farm productivity and it distance from the tree shelter-belt is statistically significant at (< 0.01) level of significance.  

Table 2. The effect of tree shelter-belt on farmers’ agricultural productivity

Productivity level (LS)[2]

Location of the farm from the tree shelter belt

Total

Far

close

Low productivity

 (Less than 1.5 millions)

60

0

60

Medium Productivity

(1.5 – less than 3 millions)

90

30

120

High Productivity

(3 millions or more)

50

70

120

Total

200

100

300

Chi – square = 67.5 (P < 0.01).  

Again, this is a very convincing relative advantage of the tree shelter-belt that should be stressed and emphasized by the extension workers to increase farmers’ level of awareness about the importance and benefits of trees and forests in improving their agricultural income which is a very crucial step towards their participation in affroestation programs.        

In order to be able to get their basic needs people in the areas affected by desertification usually develop and use survival strategies that are most likely represent impediments to development in these areas. Thus, it has been argued that in such areas desertification control must form an integral component of the socioeconomic development programs (FAO, 2006). Among these survival strategies is the work of some of the family members as hired laborers for others in nearby villages that are not affected by desertification and seasonal migration of some of them to cities which might turn into permanent migration. Table (3) illustrates the consequences of desertification in term of the extent to which some of the farming household’s members abandoned agriculture and worked as hired laborers for others and the role of the tree shelter-belt in mitigating that through revitalization of agriculture. While more than three quarters (78%) of the farmers whose farms are near the tree shelter-belt did not have any of their household members, for whom agriculture is the main occupation, worked as hired laborer for any time, only 47% of the households whose farms are identified as away from the tree shelter-belt did not have any of their members, for whom agriculture is the main occupation did not worked as hired laborer. On the other hand, while only about one tenth (11%) of the households whose farms are near the tree shelter-belt had their members worked large number (more than 100) of days as paid laborers, more than one fifth (23%) of the households whose farms are away from the tree shelter-belt their households’ members did that. This negative correlation between the average number of days that the household members worked as hired laborers for others and the distance of their farm from the tree shelter-belt is statistically significant at (< 0.01) level of significance.  

Table 3. Number of days households’ members worked as hired laborers by the location of the household farm with regard to the tree shelter-belt

Number of days household members worked as hired laborers (Days)

Location of the farm from the tree shelter-belt

 

 

Total

Far

close

Did not worked (0)

94

78

172

Less than 100 days

60

11

71

More than 100 days

45

11

56

Total

199

100

299

Chi-Square = 26.8 (P < 0.01).

The ultimate consequence of desertification is the widespread of rural conjunctional poverty (Tigani, 1990; FAO, 2006) due to reduction in agricultural production and agricultural income. One of the very detrimental effects of poverty is high school drop-out rate where the children leave the school because their families will not be able to pay the school costs and prefer to let them work as hired laborers to substitute the drop in their agricultural income. Table (4) indicates that only 23.5% of the families whose farms are away from the tree shelter-belt did not have any of their children, who are in the educational age (6-23 years), dropped out of the school compared to 69% of the families whose farms are near the tree shelter-belt. On the other hand, while 30.5% of the households whose farms are away from the tree shelter-belt had three or more of their children dropped out of the school, only 7% of the households whose farms are close to the tree shelter-belt had that number of school drop-out. Chi-square test revealed that the positive association between the distance of the household farm from the tree shelter-belt and the number of the household children who dropped out of the school is statistically significant at (P < 0.01) level of the significance. This relationship exists because of the presence of intervening variables (Bailey, 1994) that are related to the farm distance from the tree shelter-belt and in turn cause dropping out of school. These intervening variables are desertification and the family agricultural income: 

Long distance of the farm from the tree shelter-belt

The farm being more affected by desertification

Low agricultural production and low agricultural income (poverty)

Large number of school drop-out (as one of poverty coping strategies)

 

 Table 4. Number of the household member school drop-out by their farm distance from the tree shelter-belt  

Number of school drop-out

Location of the farm from the tree shelter-belt

 

Total

Far

close

No school drop-out

47

69

116

1 -2

92

24

116

More than 2

61

7

68

Total

200

100

300

Chi-Square = 60.281 (P < 0.001)

 Conclusion:

The study results are very consistent with the literature on agroforestry and role of forests and wind breaks in desertification control. Farmers whose farms are located close to the tree shelter-belt were less affected by desertification and consequently they obtained higher agricultural production and agricultural income compared to those whose farms are located far from the tree shelter-belt. Thus, the households whose farms are close to the tree shelter-belt were not compel to resort to poverty coping strategies such as hiring their family labor to others and pulling their children out of school. This is a very tangible relative advantage of the tree shelter-belt that should be stressed and emphasized by the agricultural extension service to enhance farmers’ participation in afforestation programs.   

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[1] Feddan = 0.42 hectar

[2] LS = Sudanese Pound (1 US$  = LS 2070)

 
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