Ali Darag Ali
El Sadig Yousif
1. Rangeland Ecology
Rangeland defined as all wildlands that extend within the savannah belt which is considered as not suitable for rainfed farming but for livestock and wild-life grazing. This definition applies to all marginal drylands that extend across the Desert, the semi-desert and the low rainfall savannah ecological zones. This area covers approximately 32.5 million feddans and extends over most of Kordofan, Darfur, Middle and Eastern States (Refer to the Ecological map No. 1).
The vegetation composition and distribution over the predominant ecological zones are entirely attributed to the actions and interactions of the prevailing environmental factors resultant mainly such as climate, soil, topography and the common human and animal activities. These interactions and the resultant ecological zones when coupled with the existence of a network of rivers give rise to wide diversification of land uses.
The ecological zonation map is essential to use to draw land capability classifications which are essential for the projection of the land use map. The latter is essentially used to regulate the location of Agriculture and Natural Resources uses in accordance with the actual capabilities and suitabilities of the predominant agro-ecological zone. All policies with regard to agriculture and natural resources development are usually drafted on the basis of the projected land use map. These policies and laws are usually drafted to prevent interactions that may exist in land utilizations.
2. Land Use Policy and the Size of the Rangeland
Although the country is rich in immense agriculture and natural resources, still the economic planning and development is hindered by the lack of land use maps and policies. The land use laws and policies are only effectively applicable when agricultural and natural resources utilization are defined and projected in proper land use maps.
In the absence of these maps and laws, it is rather difficult to define the actual size of the Rangeland which is currently under use. However, systematic movements of the nomads and areas of their seasonal concentration can be used to indicate the location of Rangeland currently under use (see map No.2).
The size of the Rangelands which are currently under utilization can be indirectly computed when the size of national herd and the average range forage production are determined. According to this information, the size of the Rangeland required to accommodate the grazing of the national herd can be determined as follows:-
The total number of the national herd = 35 million AU (93/94 Census).
Average feed requirement per AU per year = 0.9 - 1.0 Ton/TDN/YR.
Total feed requirement in the form of TDN = 35 x 0.9 = 31.5 million Ton of TDN.
Average forage production in the Form of TDN.
0.5 x 90/100 x 31.4/100 = 0.4 Ton TDN Feddan
The total size of the rangelands required to accommodate the grazing of the national herd =
31.5/0.14 = 225 million Feddans.
As the calculation above indicates, the actual size of the rangeland which is required to support the feeding of the national herd amounts to approximately 225 million Feddans.
3. Current Land Use
There is no accurate census with regard to the actual size of lands currently under use in agriculture or natural resources. However, the agroecological zone and the present agricultural statistic are here used to arrive at an approximate estimates of the current land uses and consequently the actual size of the rangeland which is currently available for livestock grazing.
Table No. 1: Current Land Uses
Agro-Ecological Zones |
Total Surface Area (million fed.) |
(%) of Total |
Area Cultivated |
(Mill. Fed.) |
Deteriorated or Desertified (mill. fed.) |
Forest (Million Feddan) |
Range Land (Million Feddan) | |||||
|
|
|
Irrigated |
Rain-fed (MECRF) |
Traditional |
Total |
|
|
| |||
1. Desert or Desertified |
157.08 |
28.2 |
7.84 |
|
|
7.84 |
141.40 |
7.84 |
| |||
2. Semi-Desert and Low Rainfall Savannah |
165.42 |
29.7 |
- |
- |
40 |
40 |
82.71 |
- |
42.72 | |||
3. Low Rainfall Savannah on Clay (Control Clay) |
80.90 |
14.6 |
6.00 |
18 |
12 |
36 |
Slight |
16.18 |
28.72 | |||
4. High Rainfall Savannah and Flood Region and Monit., Vegetation (Southern Clay Plain) |
153.33 |
27.5 |
? |
? |
? |
? |
- |
138.00 |
15.33 | |||
5. Total Areas |
556.73 |
100 |
13.84 |
18 |
52 |
83.84 |
24.11 |
162.02 |
86.77 | |||
Source: Recalculated by Darag from Sudan Agro-ecological Zonation and Agricultural Statistics.
Remarks on Table No. 1
1. Desert |
Cultivated areas are only along the Nile. Grazing along wadis |
|
2. Semi-Desert |
Areas deteriorated are mainly due to the expansion of rainfed farming. This zone is only suitable for grazing. |
|
3. Low Rainfall savannah on clay |
The rangeland is suitable for agricultural development. Currently this area is utilized for summer grazing. |
|
4. High Rainfall Savannah and Flood Region |
90% of this area is forest and wildlife habitat. 60% of the clay plain is suitable for agricultural development |
|
5. Total Areas |
Desertified areas include the true desert (141.1 million fed.). Desertified areas within the Savannah are only 32.71 million fed. (50% of Semi-desert and low rainfall savannah on sands). |
Table No. 1 illustrates the current land uses. Table No. 2 is a summary of the current land uses.
Table No. 2: Summary of the Current Land Use
Current Uses of Land |
Total area (million Fedd.) |
(%) of total |
Desert and Desertified Zones |
224.11 |
40.3 |
Cultivated |
83.84 |
15.0 |
Forest + Others |
162.02 |
29.1 |
Rangeland |
86.77 |
15.6 |
Total |
556.73 |
100 |
Source: Recalculated from Table No. 1.
As Table No. 1 indicates the desertified area excluding the true desert (141.4 million Feddans) amounts to approximately 82.71 million Feddans. The area desertified is entirely confined to the rangelands which extend through the semi-desert and the low-rainfall savannah on sand soils.
As indicated in the same tables (1, 2) the available rangeland does not exceed 86.77 million Feddans (15.6%). The size of the rangeland before the spread of desertification does not exceed 177.7 million feddans which is to be considered as 78% of the total size of rangeland (225 million fedd.) estimated as required to support the feeding of the national herd (35 million AU). This unbalanced situation contributes to rangeland degradation and the spread of the problem of desertification.
Previous field surveys and investigation proved that over-grazing and the unplanned expansion of rainfed farming are to be considered among the most important factors causing general land degradation. Any effort regarding rangeland rehabilitation or desertification control must be preceded by the cessation of farming in marginal lands.
4. Rangeland Development
All previous development plans had never given a significant importance to rangeland development until the problem of rangeland degradation and desertification have become a hampering element to economic development since the late seventies.
In the recent 10 Years Development Plan, angeland rehabilitation, desertification control and general environmental conservation have been incorporated. The proposed corrective measures and activities include: range conservation, rehabilitation, improvement and the modernization of rangeland management through the introduction of the ranching system.
5. Past and Current Range Development Activities
Since Harrison and Jackson (1958), no genuine work had been done with regard to vegetation botanical composition and distribution. Since Harrison's vegetation map, the vegetation floristic composition has undergone remarkable changes in most of the predominant ecological zones, particularly those which are currently affected by environmental degradation and desertification.
The range vegetation survey and mapping which was carried out by the savannah project (1962-1970), Agrar hydrotechnique and recently by SRAD all are fragmented activities and are limited to very small areas.
Lampry, in 1975, using aerial photo interpretation, surveyed the area affected by desertification within the Northern part of Kordofan. He discovered that the desert boundary which was established by Harrison (1958) had shifted down 100 km into the semi-desert ecological zone. Lampry in his report established the rate of desert encroachment as 5-6 km per year.
According to the request submitted by the Range and Pasture Administration, FAO during the period 1984-1986 conducted a range vegetation survey using aerial photo as well as satellite image interpretation. In this survey, the analysis of the AVHER (Advanced Very High Resolution Radiometer) images which discriminate between green and non-green areas (vegetation and non vegetation) was used in vegetation analysis and mapping. The outputs of this survey were the following:
1. The production of 9 vegetation map, scale 1:250,000 covering a total area of 308,025 sq. km.
2. The production of three Land Use maps, scale 1:11,000,000 covering a total area of 616,050 sq. km. in southern Northern Kordofan, middle and eastern regions.
3. Biomass production map covering the savannah belt (1.2 million sq. km.).
4. Line map (Terrain units) covering the area between Chad and the Ethiopian border, scale 1:1,000,000.
General land misuses, coupled with frequent cyclic drought during the period between 1970 and 1995, severely affected vegetation species composition and the overall biomass production per unit area. What was Acacia senegal savannah has now become semi-desert grass-land. Much of what was classed as belonging to Acacia senegal formation may have once been Acacia senegal compretom cordofanum association. The replacement of Terminalia brownii by Dalbergia amara subspecies was reported to have taken within the low rainfall savannah ecological zone.
Understory herbaceous vegetation is also reported to undergo remarkable changes due to range degradation. The botanical measurement, carried out during the Kordofan Special Fund Project (1962-1965) indicated that the trend in the vegetation composition is toward the development and survival of short-lived annual, rather than perennial, species. Wicken (1962) and Sekerman (1965) related the replacement of perennials by annuals due to the harsh condition imposed by the removal of litter and ground cover by repeated burning. This repeated burning usually causes high surface temperature to the extent that the micro-environment is not suitable for seedling germination.
Recent vegetation measurement, conducted by the Range staff at Elodya Project are illustrated in Table No. 3. As the table indicates, the species composition index within the parameter under measurement amounted to 28.3% in 1988 while in 1993 the percentage composition was reduced to 4.75%. The erosion hazard within the parameter under study increased from 30.2% in 1988 to almost 74.5% in 1993.
These botanical measurements are a full proof that the parameter under study was exposed to severe over-use after the protecting fences were destroyed.
Table No. 3: Analysis of Botanical Measurement Data Collected within Elodya Parameter during 1988 and during October, 1993
Hits along Transect Cluster (1988) |
Transect Cluster |
Total |
Average |
|||||
|
TR1 |
TR2 |
TR3 |
TR4 |
|
| ||
(%) Plant sp., Composition |
21 |
10 |
48 |
34 |
113 |
28.3 | ||
Rock |
- |
- |
- |
- |
- |
- | ||
Litter Index |
42 |
43 |
39 |
42 |
166 |
41 | ||
Bare Soil |
37 |
47 |
.3 |
24 |
121 |
30.2 | ||
Total |
|
|
|
|
|
100 | ||
Summary of Measurements
(%) spp. composition = 28.3
(%) Litter accumulation = 41.5
(%) Erosion hazard = 30.2
Total = 100
Hits along Transect Cluster (1988) |
Transect Cluster |
Total |
Average | ||||
|
TR1 |
TR2 |
TR3 |
TR4 |
|
| |
(%) Species Composition |
1 |
10 |
3 |
5 |
19 |
4.75 | |
Rock |
- |
- |
- |
- |
- |
- | |
Litter Index |
13 |
11 |
19 |
40 |
83 |
20.75 | |
Bare Soil |
86 |
79 |
55 |
78 |
298 |
74.5 | |
Total |
|
|
|
|
|
100 | |
(%) Spp. composition = 4.75
(%) Litter accumulation = 20.75
(%) Erosion hazard = 74.50
Total = 100.00
As reported by M.M.Suliman (1985) in the baseline survey of Kordofan and Darfur, the production and long-term productivity of the herbaceous biomass have been continuously and constantly decreasing due to over-use and environmental stress. The decline in the herbaceous biomass productivity is illustrated in Table No. 4.
Table No. 4: Some Changes in the Herbaceous Biomass Productivity
|
Productivity (Ton Dm/ha) | ||
Ecological Zone |
1958 Harrison |
1974/1975 Range and Pasture |
1985/87 M. Suliman |
1) Semi-desert |
|
|
|
2) Low Rainfall Savannah |
0.2 |
0.1 |
0.05 |
2.1 Northern Part |
0.24 |
0.1 |
0.14 |
2.2 Central Part |
0.33 |
0.1 |
0.14 |
2.3 Southern Part |
0.66 |
1.5 |
0.2 |
2.4 |
0.66 |
- |
0.33 |
2.5 Baggara |
0.99 |
2.5 |
0.8 |
Source: M. Suliman (baseline surveys for Kordofan and Darfur
( 1985-1987).
Research in dryland including range development is always directed to problems concerning food production. There is always a total neglect regarding rangeland and pastoral communities and pastoral ecosystem.
Proper research programmes started with the establishment of the Gazala Gawazat Range and Livestock Research Station during 1960. Aspects of range livestock nutrition were intensively investigated. Other research activities included the following:-
Vegetation trend analysis on the protected range exclosure.
Assessment of carrying capacities and testing of suitable grazing management system.
The establishment of adoptable forage plant species (stylothansis sp) for range improvement.
Range improvement using bush control methods.
Eighteen years later, the government recognized that improvement and development of grass-land agriculture might require a long-term commitment to research. The dramatic result was the creation of the Western Savannah Agricultural Research Project (WSARP) in 1978. The World Bank and the USAID contributed US$30 million to the project, which had as its focus a commitment to research on rangeland and dry-land farming systems. For such purposes four research stations were built, two in Kordofan at Elobied and Kadugly, and two in Darfur at El Fashir and Ghazala Gawazat. Although the project funds were committed, the work in research activities was very slow, and execution of the research programme is now hindered by unavailability of necessary funds.
There are social as well as psychological barriers and technical problems to overcome so as to modernize the management and utilization of the country's grazing resources and develop the livestock production. The Government, in the current 10 Years Plan (1991-2001) is interested to see that livestock production is developed as soon as possible. The modernization of the pasture management system through the introduction of ranching or the application of controlled deferment and rotational grazing systems will be limited due to the lack of basic knowledge of the characteristics of the Range Savannah forage resources.
It must be emphasized that currently there is inadequate information as to the original range forage plant composition, its seasonal changes and growth cycle in relation to the short-term climatic sequences. There is no knowledge of the actual grazing potential or the carrying capacities of the varying range types either from botanical assessment or grazing experiences.
To remedy this deficit of knowledge, the research must be oriented to measure and examine all parameters that maintain and influence range forage composition and production. The seasonal range plant composition changes must be correlated with seasonal climatic sequence as well as with the effect of seasonal burning, and with all other parameters that may influence these compositional changes.
It is acknowledged that the restoration of degraded rangeland under the current open grazing and in the absence of land use policy is a difficult task. However, the Range and Pasture Administration's previous and current programme is composed of a number of corrective measures involving Rangeland Conservation, Rehabilitation, Rangeland Improvement and Forage Production.
Rangeland Fire prevention through the construction of fire breaks provides an effective means of protecting the grazing resources. The total length of the fire lines grid executed last year (1994/1995) exceeds 31,932km.
Inspite of the fact that fire-line building using hand tools proves to be effective, although somewhat slow, it is time consuming and relatively expensive. During the late seventies, in the RMPA experiment, the use of herbicide mainly translocated chemicals, such as USTILAN in the opening of the side strips of the fire line. Herbicides were applied at the end of the dry season to prevent grass growth along the side strips during the following rainy season. Thus far, however, the experiment has been inconclusive in regard to the economic benefits to be derived from the use of chemicals which must be purchased with foreign exchange as opposed to paying local labour when using hand tools. Further investigation will therefore be required.
Using seeding and water harvesting techniques, two approaches were tested to revegetate degraded rangelands. The first approach was absolute protection to allow natural plant succession to take place when causes of degradation were excluded by fencing. This method was found to be expensive and the recovery was very slow.
The second approach was direct reseedling, using adaptable forage plant seeds along with soil treatment and water spreading for soil moisture improvement.
In consideration of the necessity to initiate immediate measures to restore the ecological balance following the drought of 1983, the RMPA combined the two approaches (reservation and seeding) and implemented a series of pilot projects across the savannah belt. Among the most important of these seeding project are Abu Fas, the sand dune fixation projects at Elbashiri, and the management of range resources around permanent water supply at Elodaya in Kordofan State. Other projects are range rehabilitation using water spreading technique, which were implemented in the Gash delta in Kassala province, and ElKoma and El Rakas pilot project in Northern Darfur state.
In 1985 the RMPA, with the assistance of FAO, purchased 12.4 tons of pasture seeds in addition to 180 kg. of inaeulant from Australia and Kenya. These seed species included Cenchrus ailiaris, Chloris gayana, Cenchrus setigrus, Stylothenses hamata and Macroptilium phasolus.
Six sites of an area ranging between 2 x 2 km to 4 x 4 km were partially fenced and reseeded after soil treatment. Table No. 5 illustrates sites selected and amount of seeds reseeded.
Immediately following first rain showers, 85 seeds were broadcasted and covered by labours using tree ranches. According to the evaluation carried out by the RMPA, the grass cover was successfully regained in most of seeded sites. Unfortunately, this demonstration was not followed through and most of the partial fences were destroyed and the established vegetation cover was overgrazed.
Laboratory as well as field trials were carried out during 1994 by the author and Dr. Jad Kerim from Western Savannah Research Project on the development of seed pellets for revegetating rangeland on sand soils in the "Girigiekh" area located to the north in North Kordofan. In these trials nine seed species were tested namely:
Pannieum turgidum Cenchrus biflorus
Pennesetum spp. Cenchrus setigerus
Aristida funiculata Chloris vergata
Cenchrus ciliaris Stylothansis hemata
The main objective of this experiment was to select the best technique to be used for seed treatment against dormancy and to choose the best mixture of earth pellet that could be applied to speed up the rate of germination so as to make sound proposal for sand done fixation through the rehabilitation of the vegetation cover in the Bara area. The results of the effect of seedling establishment as effected by pelleting are illustrated in Table No. 6.
Table No. 5: Names of Sites and Amount of Seeds Planted
Species |
Amount of Seeds (sag) |
Amount of Seeds Planted in Ranch Site (sqs) | |||||
|
|
Kassala |
P.Sudan |
White Nile |
Tendelti |
Aburukba |
El Gezira |
Cenchrus ciliaris |
150 |
14 |
25 |
25 |
25 |
25 |
2 |
Cenchrus setigerus |
200 |
14 |
25 |
35 |
35 |
35 |
2 |
Chloris gayana |
47 |
14 |
6 |
6 |
6 |
6 |
2 |
Stylothenses hamata |
60 |
14 |
7 |
8 |
8 |
8 |
1 |
Macroptilium phasolus |
60 |
14 |
7 |
8 |
8 |
8 |
1 |
Total |
517 |
70 |
80 |
82 |
82 |
82 |
8 |
Source: Sudan Experience in Range-land Rehabilitation, Darag 1985).
Table 6: Seedling Establishment as Effected by Pet Pelleting and Organic Manure
Treatment |
Pelletration Clay: Silt |
Organic Manure added (%) |
KNO3 added (%) |
Seedling (%) | |||
|
|
|
|
Cenchrus biflorus |
Paricum turgidum |
Chloris gayana |
|
1 |
3 : 1 |
- |
- |
20 |
60 |
60 |
|
2 |
3 : 1 |
1 |
- |
20 |
80 |
80 |
|
3 |
3 : 1 |
1 |
1 |
60 |
80 |
100 |
|
The result of these trials indicated that pelleted seeds with clay and silt (3 : 1) with the addition of 1% organic matter and % of KNO3 improved rate of germination of grass seeds tested. Seed treatment with cold water before pelleting for 24 hours proved to increase percentage germination of Pannicum surgidum (80%) and Conchrus biflorus (24%).
The highest percentage germination of pelleted species was scored by Choris gayana (95%), Pannicum turgidum (80%), and Choris vergata. These species are recommended to be used for the revegetation of degraded rangeland of north Bara District.
These projects include (i) Elodaya Phase II (intigrated rural development for desertification control at Eloday) (ii) Community based carbon sequestration in the North area, and (iii) The dry land husbandry project at El Khowei and Butana Camel Research Centre. All these projects are financed jointly by the Gos and the United Nations Development Programme (UNDP). All these projects are designed as self-help undertakings with substantial inputs by local land users in both planning and implementation stages.
The first project (Elodaya Phase II) covers the entire area of the Elodaya Rural Council encountering 22 village councils (60 villages) and 20,000 land users. The ultimate goal of the project is to establish a self-sustaining continuous local organizational structure to plan for proper management, conservation, and utilization of resources. These objectives will be achieved through the revegetation of denuded rangeland.
The third project is oriented to revegetate the degraded rangeland at the vicinity of Elkhowie village through the mobilization of the land users at the village site.
6. Conclusion and Recommendations
The problem which is confronting agricultural development is not the lack of resources, but perhaps because of the abundancy of these resources, virtually no planning has occurred regarding the use of these resources. The emphasis is currently oriented upon "Project Programming" rather than land use planning.
The land use map and land use policy are essential in regulating different land uses with the actual capabilities and suitabilities of the predominant ecological zones. The absence of these maps and polices have created conflicts upon the use of recourses. Mechanized farmers, for example, have intruded onto lands customarily used by traditional farmers and nomads. Nomadic people and traditional farmers, in turn, have encroached upon forest lands in search of fuel, fodder and new ground to clear and cultivate. These conflicts will continue unless land use plan and policy are prepared.
After rangeland is defined within the proposed land-use map, a vegetation survey must be prepared to project the actual current vegetating composition, forage biomass production and the actual carrying capacity of the grazing land.
It must be confessed that currently there is no information regarding vegetation compositional changes, forage production and rangeland carrying capacity. Research must be oriented towards filling this gap.
References
Ali, Ali Darag (1994). Communal Range Development. A technical report submitted to UNDP on El Odayia Integrated Rural Development Project for Desertification.
Ali Ali Darag and Jad Karim Madibo (1994). The Use of Seed Pelleting Techniques for the Revegetation of Degraded Rangelands. A Technical Report submitted to UNDP Community based carbon sequestration Project in Northern Khartoum.
AOAD (1985). Rangeland Resources in the Arab countries. A Prospective Expert Consultation on Rangeland Rehabilitation and Development in the Near East. FAO, Rome.
FAO, (1983). The African Rehabilitation Programme for Sudan.
Skerman (1962). Ecological Observational Studies in Kordofan Special Fund Project. FAO (1962-65).
