Contents - Previous - Next
This is the old United Nations University website. Visit the new site at http://unu.edu
Livestock of various types form an integral traditional part of the lives of all White Nile farmers no matter how sedentary an agriculturist they may have become. They are not popular with the authorities in the irrigated areas, but even here many farmers will maintain an interest in livestock. Everywhere else such an interest is ubiquitous
Table 5.5 shows that cattle are more significant in the Arashkol area and in the more southerly parts of the research area. Not only is rainfall more reliable in these parts, but water sources are more abundant in the dry season. Conversely camels are more important around Esh Shuqeiq and in the north. Sheep and goats are important throughout, but herds tend to be larger on the rainlands where they are an important source of secondary income.
Cattle, sheep, and goats are kept as a form of investment, and for providing meat and milk for domestic use or for sale in local villages. Milk is also sold for cheese-making. Poultry are kept by many farmers to supply eggs, and donkeys fulfil a role as beasts of burden.
TABLE 5.5. Livestock ownership
|Esh Shuqeiq||Arashkol||Qoz en Nogara|
|Percentage of farmers owning:|
|Average per owner (no.)|
|Cattle 1 1||12.1||9|
TABLE 5.6. Provision of fodder for livestock (cattle, sheep, and goats)
|Percentage of owners|
|Esh Shuqeiq||ArashkoI||Qoz en Nogara|
Table 5.6 demonstrates the farmers' provision of fodder for livestock. Nearly ail animals rely more or less on local grasses but on the clay plains aura cane is also very important. On the qoz this is less important, as it has to be purchased. Ombaz is also important, particularly in the dry season away from the river, and even more in years of drought.
There is no doubt that agricultural yields have fallen significantly throughout the research area over the past decade. For rain-fed cultivation there are no figures for the area, but government statistics for rainland as a whole point to declines of 14 per cent in yields in kg/ha for cereals between 1970 and 1980. Figure 5.5 gives the position with regard to groundnuts and sesame in the neighbouring province of Northern Kordofan. In both cases the area under crop has increased whilst yields per feddan have declined dramatically since the early 1960s.
For the research area figures do exist for cotton under irrigation. Figure 5.6 shows a generally falling yield per feddan during the 1970s for the area as a whole, whilst figure 5.7 deals with each of the individual schemes in the Ooz en Nogara Section. They all paint the same gloomy picture. Falling yields therefore appear to be one of the most significant features of the changing agricultural economy of the research area.
Six groups of factors for this may be postulated and relate to: technical problems; labour situation; administration; environmental and ecological conditions; land difficulties; and the socio-economic position.
FIG. 5.5. Rain-fed crop production in Northern Kordofan
FIG. 5.6. Recent cotton trends in the Ed Dueim Unit
Although tables 5.7 and 5.8 show average cotton yields for the area as a whole and for specific schemes, it is clear that output varies within individual schemes. Poor level Iing is a major cause. On the Qoz en Nogara Scheme the areas near to Wad Sarih and Khor el Mutraq in particular give the poorest yields. They are slightly higher than the surrounding fields and consequently water often fails to irrigate the hawashas properly. Each section is levelled separately each season and consequently the problem remains as a permanent feature rather than as a shortterm complication. The areas which suffer most from bad levelling tend to be on the peripheries of schemes and are also the ones most vulnerable to animal invasion.
Ploughing often leaves much to be desired. On the irrigation schemes, it is usually mechanized but the tractor drivers are often unskilled. Although it is each farmer's responsibility to repair damaged bunds and canal banks, gaps inevitably open up and serious local flooding can occur. If plants are drowned, farmers need to act swiftly to save them or to plant a new crop, depending on the time of year.
FIG. 5.7. Recent cotton trends on schemes in the Qoz en Nogara Section (*No data)
Near Esh Shuqeiq, tractors were used for ploughing rainland in the early 1970s despite warnings that the qoz was illsuited for mechanization (Osman, 1966). This practice removed the top 10 to 13 cm of soil. Fortunately the dangers were soon realized and the use of tractors was abandoned, though a legacy of reduced soil fertility remained.
Spraying is undertaken to limit pests and diseases. Spraying from the air was attempted but abandoned due to ineffectiveness and cost (Mohammed, 1980). The system adopted at present is to spray chemicals manually; this gives uneven coverage and is often not carried out if there is a labour shortage. This must be considered a significant, even if non-quantifiable factor.
Use of Fallow
The absence of fallow at Arashkol and its unorganized use at Esh Shuqeiq have been significant factors in reducing soil fertility.
The significance of weeds in reducing yields of agricultural crops on irrigation schemes has been discussed by El Arifi (1978) in relation to the Khashm el Girba Scheme. The picture presented there is equally applicable on White Nile pump schemes, where weeds not only choke crops like cotton but also compete with the desirable crops for moisture from irrigation water and block the smaller canals.
Grass and weed infestation can be equally serious for rainland cultivation. Here it is largely a reflection of poor farming methods and noticeable variations can be seen between adjacent bilad, depending on the amount of effort put into weeding by the farmer.
This is an important problem. On the Qoz en Nogara Scheme 78 per cent of farmers said that labour supply was decreasing; at Arashkol, 63 per cent; and at Esh Shuqeiq all of the farmers employing non-family seasonal labour complained of it. In its simplest form, this is due to outmigration (usually to urban-based jobs) exceeding
the level of new migrants (mainly from the west). At Arashkol the problem is intensified by the close proximity of irrigation schemes which offer higher wages than rainland farming. Gadir (1976) has pointed out that in years of good rainfall labourers stay longer on the baja to grow their own crops and herd livestock, thereby reducing the labour supply along the river. Labour shortages can seriously affect the efficiency of agricultural operations, and tasks such as weeding are insufficiently carried out.
Not only are the rainlands with their lower and decreasing yields less attractive to labour than the pump schemes, but they in their turn are suffering increased competition from other more attractive areas with high labour requirements, including the Gezira, Rahad, and Kenana Schemes.
The high incidence of sharecropping does not create a sound economic environment in which to work. Many of the absentee tenants own shops, operate lorries, work in the Three Towns, or sojourn in the Gulf States. This has been partly encouraged by the greater economic opportunities offered in these environments and parlty by the gradual deterioration of crop yields in the research area. Once crop sharing begins, not only does it seriously affect the morale of the new farm labourers, but it often makes it inevitable that farmers should seek alternative supplementary sources of income, the most common being livestock rearing and labour on irrigation schemes, especially on the small private schemes which offer higher wages than those under the Agricultural Corporation. Significantly, El Zubair (1976) concluded that irrigation hawashas tended to have lower Yields when the farmer had a secondary occupation. Indeed, the Ed Dueim pump scheme was finally disbanded in 1976/77 by the Agricultural Corporation and handed over to the town council, because most of the farmers were committed to their urban-based employment rather than to agriculture. Since then the scheme has become a much less formalized agricultural institution and now provides the town with various necessities, including vegetables.
Sharecropping itself is a significant cause of labour shortage on the pump schemes, since many of the sharecroppers were themselves originally seasonal labourers, and by becoming permanent farmers they have reduced their own workforce. Nowadays it is becoming necessary to seek temporary workers for the irrigation schemes from much further afield, for example from Suq el Helba and Kareinik.
Morale is not raised by the unions, which seem not only to be ineffective but also to have leaders who are unrepresentative of the workforce.
The irrigation farmers are highly critical of the White Nile Agricultural Corporation, whose administrators are said to be out of touch with the farmers' needs, lacking in managerial skills and insufficiently objective in their approach to their work.
In the case of the Qoz en Nogara Scheme there exists a clear dichotomy between the aims and objectives of the administrators, on the one hand, and the needs of the farmers on the other. In addition to the ineffectiveness of the labour unions the problem is intensified by the failure of administrators to visit the scheme regularly, with the result that there is a notable lack of supervision. Some inspectors seem to lack even such basic knowledge about their scheme as its size, the number of tenants, and the water requirements for the various agricultural operations.
The administration often fails in its obligation to supply water for the farmers' aura crop. The problem of poor levelling is exacerbated by the illegal sale of water to neighbouring private schemes to boost the private income of some of the administrative staff. Ahmed ( 1976) identified this same problem on the Shabasha Scheme. Not only does this lead to lower levels of aura production, but it seriously affects the morale of farmers. Declining morale is also attributable to the belief that the richest farmers, those with relatives in the White Nile Agricultural Corporation, and scheme servants always secure the most favourably located hawashas.
A poor track record in decision-making is another accusation levelled at the Corporation. On the Qoz en Nogara Scheme the decision to abandon fallow for four years has been fundamental in causing soil deterioration. The unwillingness of administrators to consider crop diversification is also viewed with frustration by many farmers.
The late delivery of fertilizers has severely affected cotton yields. When fertilizers were delivered in July and August they could be applied both before and after sowing, but now they are delivered in November when their effectiveness is severely restricted. The Corporation has also been accused of being slow in paving farmers for their cotton, with the result that farmers often face serious problems of cash flow. As there are no formal lending institutions, farmers are able neither to finance adequately the inputs for the early part of the next season nor to arrange for work to be done at the best time, with the inevitable results for the new season's crop.
Environmental and Ecological Problems
The area has faced severe droughts in recent years, and this has had a fundamental impact on agriculture. In the rainfed areas, every interviewee considered the effects of drought on their crops to be "serious." Twenty-five per cent of the farmers at Arashkol who currently grow just aura claim to have formerly grown other crops such as sesame as well. Drought was said to be a significant factor in the trend towards aura. Rain failure can be serious on the irrigation schemes as they are dependent upon rainfall in July when the Jebel Aulia reservoir is usually too low for the pumps to be effective. Consequently drought can restrict the growth of the crops in their initial stages and so reduce yields in the final harvest.
The effect of drought on livestock has regional variations, Table 5.7 shows that drought is considered more serious at Arashkol than at Esh Shuqeiq. In drought years both areas widely use ombaz as a fodder. However, at Arashkol there are fewer extensive pastures close at hand and so greater movement for grazing is required, and this in itself has a deleterious effect on livestock. Increasing numbers of cattle in the Arashkol area in recent Years, and a concentration on them rather than on sheep and goats, exacerbates the situation, as cattle need better pastures, and with pasture deterioration they suffer more than the hardy sheep and goats. This situation affects livestock kept by irrigation farmers, since cattle are abundant in the south of the research area. When necessary they are taken to the baja by the village shepherd, but one mitigating factor here is that scheme herds tend to be smaller and are less important economically than their rainland counterparts.
Flooding can be as serious as drought on some occasions. In 1978 it destroyed crops throughout the research area. Near Arashkol, flooding and waterlogging destroyed seedlings; at Et Tura'a, Idd El Ud, and just north of Esh Shuqeiq rain cultivation in a khor bed was completely destroyed. This has had a permanent impact because the flood deposited an exceptional amount of sand, burying the fertile soil.
TABLE 5.7. Effect of drought on livestock on rainland farms (percentages)
This is much more difficult to assess. Active sand dunes are not extensive in the research area, the main ones being near Et Tura'a, but this does not mean that desertification is not present (Ibrahim, 1978). Mensching and Ibrahim (1977) suggest that the ecologically sound climatic limit for millet production is 500 mm. However, Jackson (1977) has pointed out that it is possible to grow aura in areas with as little as 125 to 200 mm of rainfall when this is concentrated in the coolest part of the day, a situation occurring in the research area. From the assertion of Mensching and Ibrahim it might be that the northward extension of millet cultivation into the research area, under rain-fed conditions, is itself a possible cause of desertification, and it is not surprising that yields of these crops should vary dramatically from Year to year. The clearest expression of desertification in the area is the piling of sand against crop residues and the growth of small sandhills on bilads near Arashkol.
On the irrigation schemes desertification is potentially most serious where sand dunes are adjacent to hawashas. El Zubair (1976) has pointed out that blowing sand changes the nature and composition of soil and reduces its fertility. Sand covering makes the soil of the clay plain more permeable, increasing the demand for water. Ibrahim (1976) describes desert creeping onto irrigation schemes, but during field work no such evidence was found where shelter belts exist.
The most serious effects of desertification on the irrigation schemes are indirect. Ibrahim (1976) points out that haboobs (dust storms) can dirty cotton lint, reducing its value, and make cotton picking more difficult. He suggests that haboobs have become more frequent in recent years.
Soil fertility is apparently decreasing, not only owing to inadequate use of fallow but also because soil nutrients on irrigation schemes are gradually being exhausted and soil salinity is increasing. This has occurred in the Es Sufi basin especially
Water Hyacinth (Eichhornia crassipes)
This is an ecological problem of varying spatial and temporal significance, which first occurred along the White Nile in 1957/58 (Gay, 1958; Gay and Berry, 1959) and primarily affected navigation (Davies,1959). However, it does get into irrigation canals and blocks pumps, especially when a southerly wind is blowing, concentrating the plant in the more northerly parts of the Jebel Aulia reservoir. Sometimes it can be used as supplementary feed for livestock.
Pests and Diseases
Dukhn and sesame are particularly attractive to birds and subject to rat infestation as well as plant diseases. Consequently the severest effects were reported at Esh Shuqeiq (table 5.8). However, the problem is apparently a changing one. Although 76.6 per cent of farmers interviewed at Arashkol said their crops were not seriously affected by pests and diseases, many of them believed that the problem is getting worse. Pests and diseases do not appear to be as significant on the irrigation schemes as on rainland and have not been responsible for any of the major crop fluctuations in recent years.
The best known depredations by birds involve the weaver bird (Quelea quelea oethiopica), but only rarely does it venture north of Kosti into the research area (Bacon, 1954). Of much greater importance here is the common sparrow (passer domesticus arboreus), which is an infamous seed-eater. Dura has been less vulnerable since the zirzira variety was introduced (Direr, 1970), but dukhn is still seriously affected. Sesame is also attacked by birds but the effects are not usually serious. Rats (Arvicanthis festicularis) are most serious on the qoz, where their numbers have reached plague proportions in the past; they attack sesame and dukhn in particular. The introduction of new poisons has dramatically reduced their depredations, Caterpillars, millipedes, grasshoppers, ants, locusts, and worms all have periodic local significance in reducing Yields, especially of sesame.
Common pests and diseases affecting cotton are well documented (Bacon, 1954). The most important ones in the research area are leaf curl, black arm, leaf-eating fleabeetle, thrips, jassid, whitefly, and aphid. Small insects are also a great problem for aura and dukhn, especially a small, grey beetle (Tanymecus sparsus) which attacks the crop shortly after germination. As this insect seeks cracks in the soil to shelter from the midday heat, it tends to be most widespread on the clay plain. Before the completion of the Jebel Aulia Dam, the aura stem-borer (Sesamia cretica) was a great problem and has been known to destroy entire crops in some parts of the clay plain. Since 1937, however, the safra species of aura, which was particularly vulnerable, has largely disappeared and the seriousness of the pest has been reduced (Bacon, 1954). Aphids also attack aura on the clay plain.
TABLE 5.8. The effect of pests and diseases on crops (percentages)
|Esh Shugeiq||Arashkol||Qoz en Nogara|
Buda (Striga hermonthica) is the most serious of the plant parasites. Dura and dukhn can be badly affected, especially the former. Once the parasite begins to grow it must be removed manually, a long and labour-intensive process. Changing the variety of the aura or dukhn may ease the problem temporarily. Buda tends to be less serious on irrigated areas, providing crop rotation does not allow the parasite to sustain its growth for more than a few months (Bebawi et al., 1980). Grass and weed infestation can also be very serious if not kept under control. The main weed affecting cotton is e/ seid (nutgrass, Cyperus rotundus) (El Zubair, 1976), which is a great problem on irrigation areas in the Sudan at large (Andrews, 1954).
Livestock as well as crops suffer from various pests and diseases and are discussed in chapter 6.
Competition for land and conflicts over its use have had significant implications for agriculture. Around Esh Shuqeiq, drought in recent years has led to an increase in cultivated areas in an attempt to increase overall crop yields. This has put considerable strain on the limited amount of suitable land available. Land poaching has resulted, especially of land left fallow by farmers seeking to improve its fertility. Local police at Esh Shuqeiq are of the opinion that this problem is becoming worse each year. Land poaching does not appear to be as significant a problem on the clay plain as on the qoz.
The invasion of rainland farms by animals is a far greater problem than land poaching and is significant in all the agricultural zones. Around Esh Shuqeiq the problem is greatest when a bilad lies adjacent to a major route used by livestock travelling to and from a water point. Often the animals are not supervised sufficiently and they wander onto the bilads, both eating and trampling crops. According to local police and farmers, some semi-nomads encourage their animals to invade farmland in drought years as they know that the penalties are to them less than the cost of losing animals. Reports to the police can lead to fines of úS100, but rarely does this happen. Farmers are encouraged by their families to settle a dispute privately. One farmer at Umm Ruqeiba, near Esh Shuqeiq, had 14 cows wandering through his dukhn. Although he caught the animals, his relatives prevented him from taking them to the animal pound. Instead, they ordered the owner of the cows to give 0.5 k of dukhn per head of cattle in compensation. The farmer said that this was unfair as he lost several times more than this, but to have followed the legal procedure would have been to no avail, as the courts would have given the same decision. At Esh Shuqeiq, all farmers interviewed claimed that they suffered from land competition of this type and only 60 per cent thought that present procedures dealt with the problem satisfactorily
Animal invasion at Arashkol is somewhat less significant. Of those interviewed, 66.7 per cent complained of animal invasion, but three-quarters of these said that a satisfactory solution based on fines and compensation had been achieved in their area. One possible reason for the difference between Arashkol and Esh Shuqeiq is the existence at Arashkol of a regular water supply nearby in the canals of the irrigation schemes.
Animal invasion has been perhaps the greatest problem of all on pump schemes in recent years. Invasion of schemes by animals during the hot dry season is particularly common. Every interviewee complained of this problem and thought that control measures were ineffective. Offending animals are taken to pounds and fines are levied, but in practice few animals are caught and, according to some farmers, police are often bribed by animal owners to allow their livestock to graze on the aura and cotton hawashas before the completion of the harvest, especially in years of deficient rainfall. Some farmers now form syndicates to hire their own private guards, but their effectiveness is so far limited. Ahmed (1976) wrote of heavy crop losses on the Shabasha Scheme in 1974/75 due to animal invasion, and the low cotton yields on the Qoz en Nogara Scheme in 1979/80 were largely blamed on the same thing. Farmers sometimes contribute to their own difficulties by letting unsupervised donkeys trample and graze on their own and neighbours' hawashas.
Animal trespass is becoming an increasingly serious problem. Eighty-five per cent of the interviewees at Esh Shuqeiq said that the problem had become worse over the past decade and was at its worst during drought years. A similar proportion (80 per cent) at Arashkol expressed similar apprehensions and on the Qoz en Nogara Scheme almost 90 per cent of the farmers thought that the problem was getting worse. On the irrigation schemes in particular it was felt that penalties for animal trespass were not severe enough.
The poor state of Sudan's economy results in numerous shortages of commodity goods, some of which seriously affect the efficiency of the pump schemes. These include insecticides, such as DDT, petrol, and spare parts for pumps and tractors (Ahmed, 1976). Pump stoppages resulting from these shortages are one of the most significant reasons for serious crop failures on the irrigation schemes. The lack of workshops on the schemes to repair machinery is a further contributory factor (El Zubair, 1976).
Lost working time is a greater problem on some schemes than others. Farmers on the Qoz en Nogara Scheme spend a considerable time travelling between their homes and their hawashas. The division of the scheme into three units has helped to ease this situation (fig. 5.4).
Of much greater importance, however, is absence due to health problems. The expansion of irrigation schemes in the White Nile,as elsewhere in the Sudan,has been accompanied by an increase in water-associated diseases, notably malaria, typhoid, and bilharzia (schistosomiasis) (Amin, 1977). The problem is most acute where people are dependent upon drinking water extracted directly from irrigation canals, or from hafirs supplied by canal water. The lack of health facilities exacerbates this problem (El Zubair, 1976). Although the qoz is relatively better off in the sense that less stagnant water reduces the incidence of disease, it suffers from its remoteness in that it is much more difficult to implement health measures (De Vajda, 1966).
Of uncertain importance is the theft of crops, notably cotton. Gadir (1976) gave an example from the Eraig Scheme where cotton was stolen in the harvesting season and sold to owners of private schemes. However, crop stealing is not generally considered to be very serious in the White Nile area, and as El Zubair (1976) has pointed out, cotton stealing doesn't affect the final total, just its distribution
Loss of animals mainly as a result of drought, has been serious for many farmers. Drought leads not only to direct losses from lack of pasture and water but also to losses from indirect causes, in that weak animals are more likely to succumb to disease; the gathering of large numbers of animals around a more limited number of water points has the same effect; and owners are more anxious to sell livestock if they feel they are going to lose them anyway. Eight-five per cent of the farmers at Esh Shuqeiq and 94.7 per cent at Arashkol claimed that their livestock had decreased in number at some time over the last decade from this cause. Of these, 47 per cent of the farmers at Esh Shuqeiq and 11 per cent at Arashkol claim to have restored their herds. Some farmers have been tempted to increase their herds as an insurance policy against future drought losses. Livestock are an uncertain economic asset, being particularly vulnerable to drought and pasture deterioration. On the other hand, within limits livestock can be moved from one place to another when drought strikes. Nevertheless, recent droughts have forced many rainland farmers to change their livelihoods, having both lost animals and experienced crop failure. Livestock losses are less serious for irrigation farmers as they have a more reliable annual income from the cultivation of crops and are less dependent on livestock.
In an inflationary situation, all farmers in the research area are having to face the problem of rising prices. The rising costs of equipment, fuel and spares, and labour is becoming very serious for the efficient working of some of the pump schemes and the total cost of "inputs" is beginning to call into question the viability of cotton cultivation.
Conclusion: The Future of Agriculture in the Research Area
Clearly, agriculture here is facing serious problems. Most of these have arisen or become much worse within the last 12 years. Since 1968, the area has suffered several years of drought which, apart from their direct effects, have encouraged migration away from the area. This in turn has led to labour shortages and has intensified the many other problems of rainland farming. The irrigation schemes have not been able to function as well as they should. Numerous administrative changes have added to the inevitable problems created by Sudan's severe economic situation. The costs of cotton production have increased sharply at a time when the prospects and prices for cotton are gloomy.
The inevitable question that arises is: What should be done to put the situation right? A reorganization of rainland agriculture, ensuring a better separation of cropping and livestock grazing, with heavy penalties for trespass, and a firmer rotational system of cropping on arable land would both be helpful. Desertification can possibly be minimized by a better overall grazing strategy, with control over animal numbers and heavier fines for tree cutting. The rainland farmers are susceptible to subtle environmental and ecological changes. Simply to demand a change of crop or land-use management and expect that this will be done without assistance is not enough. Subsistence farmers can ill afford the risk of experimentation (Mirghani, 1966). Gradual change with incentives applicable to the farmer is what is required.
Administrative shortcomings have been a main problem on irrigation schemes and should not be too difficult to put right. However, despite being partners, tenants have neither scope for individual initiative nor adequate incentives to improve their own efficiency. Thornton (1964) pointed out that irrigation schemes should have the flexibility to change in accordance with environmental, ecological, and economic circumstances, but such adjustments occur far too slowly in the research area. The organizational structure of government pumpscheme management is simply not capable of coming to quick enough commercial decisions. Wheat appears to be economically more viable than cotton, but there is little grown, as the farmers have neither the incentive to put in the greater amount of effort that is required nor the subsidies that are available for cotton growing (Gadir, 1976). Rice cultivation by irrigation south of Ed Dueim is being undertaken on the Umm Takkal Scheme using "squatter" labour from Ed Dueim town, but consideration is also being given to extending this crop as far north as Wad Nimr (EI Fadni, 1976). Success with this crop could have important implications for irrigated agriculture throughout the research area.
Fruitful lines of research which could also assist in putting agriculture in the research area onto a firmer foundation include: a more detailed analysis of the interaction of man and animals on the one hand with the land on the other; an investigation of the possibilities of secondary occupations providing capital for agricultural investment; and an in-depth study of the interrelationship of physical conditions, soil fertility, watering systems (on irrigation schemes), and cropping patterns.
The author wishes to thank all of those who helped in the preparation of this work. In particular he would like to mention his field interpreters (Abdel Monam Muzzamil Abd Alla and Mohamed Adam Khalil) and Harun the landrover driver. He also wishes to record his debt to the Social Science Research Council for financial assistance, the British Council for providing a landrover, and the staff of the geography departments in Swansea and Khartoum Universities for much assistance. Above all he wishes to thank the agricultural officials and farmers in the White Nile Province who were not only willing to be interviewed but also offered generous hospitality.
Abd el Ati, H. A. 1976. "Dueim Town-Growth and Functions." Unpublished B.A. dissertation. University of Khartoum, Khartoum.
Abdulla, A. A. 1974. "Land Use in South West Dueim District." Unpublished B.A. dissertation. University of Khartoum, Khartoum.
Ahmed, A. O. 1976. "An Economic Survey of Shabasha Pump Scheme." Unpublished B.A. dissertation. University of Khartoum, Khartoum.
Ali, S. M. N.d. "The Ed Dueim Pump Scheme." Unpublished B.A. dissertation. University of Khartoum, Khartoum.
Allan, W. N., and R. J. Smith. 1954. "Irrigation in the Sudan." In J. D. Tothill, Agriculture in the Sudan. pp. 593-631.
Amin, M, A. 1977. "Problems and Effects of Schistosomiasis in Irrigation Schemes in the Sudan." In E Barton-Worthington, Arid Land Irrigation in Developing Countries, pp. 407-411.
Andrews, F. W.1954. "Weeds in the Sudan." In J. D. Tothill,
Agriculture in the Sudan, pp.401-403. El Arifi, S. A. 1978. Khashm El Girba, Collection of papers from the University of Khartoum, Khartoum,
Bacon, G. H.1954. "Crops of the Sudan." In J. D. Tothill, Agriculture in the Sudan, pp.302-400.
Barbour, K. M. 1961. The Republic of the Sudan. University of London Press, London.
Barton-Worthington, E., ed. 1977. Arid Land Irrigation in Developing Countries. Pergamon, Oxford.
Bebawi, F. F., G. A. El Hag, and M. Khogali. 1980. "Striya hermonthica." Paper submitted to Task Force Meeting on Arid Lands, University of Khartoum, 17 August 1980.
Bolton, A. R. C. 1954. "Land Tenure on Agricultural Land in the Sudan." In J. D. Tothill, Agriculture in the Sudan, pp.187-197.
Burnett. J. R. 1954. "Crop Production." In J. D. Tothill,Agriculture in the Sudan, pp. 275-301
Davies, H. R. J. 1959. "Effects of Water Hyacinth (Eichhornia crassipes) in the Nile Valley." Nature, 184: 1085-86.
----. 1964. "The West African in the Economic Geography of the Sudan." Geography, 49: 222-235.
De Vajda, A. 1966. "The Use of Water in Sudan's Agriculture." In D. J. Shaw, Agricultural Development in the Sudan. Vol.2, pp.73-84.
Dirar, A. R. M. A. 1970. "The Economics of Agricultural Production on the Private Pump Schemes in Kosti and Ed Dueim districts." Unpublished M.A. dissertation. University of Khartoum, Khartoum.
El Fadni, A. E. R. A. 1976, "Rice Production in the White Nile Province." Unpublished B.A. dissertation. University of Khartoum, Khartoum.
Gadir, A. G. M. A. 1976. "EI Eraig Pump Scheme." Unpublished B.A. dissertation. University of Khartoum, Khartoum.
Gay, P. A. 1958. "Eichhornia crassipes in the Nile of the Sudan." Nature, 182: 538-539.
Gay, P. A., and L. Berry. 1959. "The Water Hyacinth: A New Problem on the Nile." Geog. J., 125: 89-91.
Grigg, D.1978. The Harsh Lands. A Study in Agricultural Development. Macmillan, London.
El Huda, A. G. A. 1964. "The Urban Geography of Ed Dueim." Unpublished B.A. dissertation. University of Khartoum, Khartoum.
Ibrahim, A. J. 1976. "The Effect of Desert Creep in White Nile Province." Unpublished B.A. dissertation. University of Khartoum, Khartoum.
Ibrahim, F. N.1978. The Problem of Desertification in the Republic of the Sudan with Special Reference to Northern Durfur Province. Monograph 8. Science Research Council, Khartoum.
Idris, H. A. l. 1960. "White Nile Pump Schemes." Unpublished B,A. dissertation. University of Khartoum, Khartoum,
Idris, K. M. 1964. "The Jebel Aulia Dam and Its Significance." Unpublished B.A. dissertation. University of Khartoum, Khartoum.
Jackson, l. J. 1977. Climate, Water and Agriculture in the Tropics. Longman, London,
Mackinnon, E. 1954. "Blue Nile Province." In J. D. Tothill, Agriculture in the Sudan, pp.762-809.
Mensching, H., and F. N. Ibrahim. 1977. "The Problem of Desertification in and around Arid Lands." Applied Sciences and Development (Tubingen),10: 7-43.
Mirghani, A. R. 1966. "Problems of Increasing Agricultural Productivity in the Traditional Sector." In D. J. Shaw, Agricultural Development in the Sudan. Vol. 2, pp.98-103.
Mohammed, A. A. 1980. White Nile Arabs. Athlone Press, London.
Osman, M. S.1966. "The Possibilities and Problems of the Mechanization of Agricultural Production in the Sudan." In D. J. Shaw, Agricultural Development in the Sudan. Vol.2, pp. 341-375,
Persse, Stewart, Pirie, and McKey. 1899. "Omdurman to Fachi Shoya by the West Bank." In W. Garstin, Supplement to the Handbook of the Sudan, pp. 19-21.
Shaw, D. J.1966. Agricultural Development in the Sudan. Philosophical Society of the Sudan, Khartoum. 2 vols.
Sudan Government. 1948. The Sudan. A Record of Progress 1898-1947. Khartoum.
---. 1955. Irrigation by Pumps from the Nile in the Sudan. Ministry of Irrigation, Khartoum.
Thomson, J. R.1951. Pump Scheme Management on the White Nile. Bulletin 7. Ministry of Agriculture, Khartoum
Thornton, D. S. 1964. "The Organisation of Production in the
Irrigated Areas of the Sudan." J. Agric. Econ, 16: 286295.
Tothili, J. D. 1954. Agriculture in the Sudan. Oxford University Press. Oxford.
Vaughan-Lee, A. G. 1941. "The Gebel Aulia Dam." J. Inst. Civil Engineers, 16: 326-350.
Wingate, R. 1891. Mabdism and the Egyptian Sudan; reprinted 1968. Frank Cass, London.
Wynn, R. F. 1968. "The Economics of Pump Irrigation from
Nile in the Sudan." Sudan Notes and Records, 49: 83-103.
El Zubair, S. A. 1976. "Problems of Cotton Production in the White Nile and Suggested Substitutions." Unpublished B.A. dissertation. University of Khartoum, Khartoum.
Contents - Previous - Next