Background
The White Nile Province in the Central Region of Sudan is one of the important Gum arabic production areas in the country. It belongs to the 300-600 mm rainfall zone in which the gum source: Acacia senegal thrives naturally, especially in the vast savannah areas west of the White Nile river.
Gum arabic, local source of income and nationally important export article, is collected either from privately owned gum gardens or from natural stands of Acacia senegal. The gum gardens form a traditional bush fallow farming system in which bush fallow and combination of cereal and gum arabic rotate. If ample time, 7-10 years, is allowed for the fallow, the period is enough for acacias to regenerate and the soil to restore its fertility.
In the 1970s and 1980s the ecological balance of this system has been disrupted. In the pressure of growing population and consequent demand for cereals, the fallow part of the cycle has been diminished. Acacias can no longer regenerate. Deforestation of Acacia senegal has resulted.
Following the deforestation, the White Nile province has drifted into fuelwood shortage. The natural savannah vegetation can no longer sustain the growing fuelwood demand, the demand which has increasingly been exacerbated by the growing hunger for charcoal in Khartoum. Desertification has followed: landscape bared of trees has lost its topsoil due to windblow. Without topsoil arable crops do not yield enough and the peasant farmers are forced to migrate to other areas.
Such development was behind the start of the Sudan-Finland forestry programme, the agreement of which was signed on 10 May 1979. The objectives for the cooperation were set as:
- combatting desertification
- production of fuelwood and gum arabic
- improvement of living conditions of the local population
Forestry development of 10 years
The Sudan-Finland forestry cooperation was initiated by fielding two forestry advisers in Sudan in late 1979. The logging adviser had to identify and prepare project profiles in forestry and forest industries. The silviculture specialist provided technical expertise on the silvicultural aspects of gum arabic production and on establishing plantations for pulp and paper raw material production.
The first phase of the programme lasted for two years, 1979-1980. The main finding was in the methods of seedling production and planting efficiency. Seedlings that were grown in improved pot trays were 24 times faster to plant than the traditional polythene tube seedlings. As the efficiency in planting is a bottleneck in a short Sudanese planting season this research finding led to a decision of establishing a new central nursery in the White Nile Province (in Um Hager) using the improved pot tray method.
Systematic development of nursery methods continued during the second phase, 1981-1982, of the programme. Besides Acacia senegal, production of mesquite (Prosopis juliflora) was started. During the second phase a feasibility study on the development prospects of pulp and paper industry in Sudan was also completed. Its message was clear: there is not sufficient forest resources for chemical wood industry in the country. Further emphasis was given to continuing the reforestation development.
During the third phase (1983-1985) the programme moved into large scale reforestation. Then years 1983 and 1984 were the years of severe Sahelian drought, and experience in planting during harshest years of the decade was gained. The importance of every link in the chain of plantation establishment, starting with seed and ending with last weeding of the saplings, was learnt through trial and error, through plantation failures as well.
The 4th phase (1986-1988) of the programme was easier as to the rains. Plantation establishment was now successful and a remarkable hectarage was planted. By the end of 1988 altogether 4 million seedlings were raised, and 5400 hectares of new forests were planted in the White Nile project. In 1989 the project was moving into its 5th phase (1989-1993).
Lessons learnt
Erratic rainfall is the limiting factor for successful reforestation in the forest line areas of the White Nile province. In the period 1979-1988 two years were so dry that the planting was not successful: 84 millimetres of rain in 1983 and 56 millimetres in 1984. The other years were moderate, the rainfall remained around the average level of 380 millimetres, and the success of reforestation was acceptable.
Studying the long-term rainfall statistics reveal that a year of severe drought has occurred once in every 15 years period. On the other hand, once in the same period such an abundant rainfall occurs that both natural Acacia regeneration and reforestation with almost any method is successful. The problematic years are the remaining 13 out of 15: which kind of reforestation methods are needed that the planted seedlings can survive over the first dry season. The following lessons have been learnt:
- soil cultivation before planting is essential
- vigorous seedlings ready for planting on 15 July
- seedlings are watered in the nursery before dispatch
- short transport distance to the planting site
- immediate planting
- seedlings are watered once at planting
- planting is completed within 4 weeks
- seedlings are weeded at least once after planting
- seedlings are guarded or fenced against goats
In every link of the chain enough skilled labour is essential. The critical period is the true planting season, 15 July – 15 August, as this is the peak season of agriculture as well. In fact, the planting work has faced labour shortage.
The importance of soil cultivation before the planting was learnt as part of the research and development in the rainfall harvesting. By testing different ploughing methods, it was found out that the survival of the planted seedlings was the highest, not in the seemingly wettest point at the bottom of the ploughing furrow, but in the seemingly driest point on the top of the ploughing ridge. This finding has led to further development of the soil cultivation methods.
Future prospects
During the first decade of the Sudan-Finland forestry programme applicable reforestation practices for the White Nile province have been learnt. Moderate success can be expected in 9 years of 10 if appropriate reforestation methods with skilled labour are used.
The task in front, however, is enormous. Seedlings for all the plantation establishment, for instance, cannot any more be supplied from one central nursery. Therefore, satellite nurseries nearer to the planting sites are needed.
Large scale reforestation cannot be executed as centrally run government exercise. In one way or another people’s participation is needed. Adoption of private gum arabic production using planted Acacia senegal seedlings instead of the slower and more extensive bush fallow system is one of the following objectives of the project. This needs additional effort and inputs in extension.
Another line for increased people’s participation is development of suitable agroforestry practices. Encouraging results have been achieved with alley cropping of mesquite and sesame or karkadeh (Hibiscus sp.). As nitrogen fixing tree mesquite fertilizes the soil for the arable crops. In addition, it shelters the crops from windblow, provides forage (pods) for the livestock and fuelwood for the people. Agroforestry is also the key to secured guarding of the planted seedlings; arable crops are guarded anyway against cattle and goats.
After 10 years’ reforestation a considerable number of gum arabic and mesquite have been planted. Reforestation practices have become known for the local people. It is expected, at least hoped, that general awareness about importance of trees in the forest line sites has increased. Besides established plantations there still remains considerable natural acacia forests in the district. All the forest resources are worthwhile to bring under forest management planning, a new activity in the new phase of the programme.
Ten years’ reforestation experience in the White Nile has already shown that desertification can be combatted. This needs active cooperation and further development in finding the most suitable nursery production methods, skills of plantation establishment and ways of sustained forest management. They all belong to the operation forest line which gears towards the improvement of living conditions of the people in the White Nile area.
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Comment on 20 Oct 2020:
I worked 1989-1990 as Forestry adviser in Finnida. The Sudan – Finland Forestry programme was one of the most significant development aid programmes of Finland, especially reviewing it now 30 years later from the point of view of Carbon husbandry and Climate forestry in Sahara and Sahel belt.
Veli Pohjonen 