Vulnerability and Potential Adaptation Options of Agricultural Sector to Climate Change in Sudan

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1 Vulnerability and Potential Adaptation Options of Agricultural Sector to Climate Change in Sudan Abdelrahman K. Osman 1 Abstract Agriculture is the main sector of the Sudan s economy and it is the major livelihood source for more than 70% of the population. Agriculture has been identified as one of the three highest priority sectors most vulnerable to climate change. Several recent studies have indicated the substantial decline in precipitation and rising in temperature in several parts of the country. Current and potential impacts of climate change include reduction in yields and duration of crop period, increased occurrence of dry spells, warm and too short winter, land degradation, increased water requirements and decrease in water availability, increased occurrence of dust storms and sand blast, and socio economic impacts. The degree of vulnerability differs, with the traditional rainfed farming as the most vulnerable. Within this sector, chronically vulnerable and food insecure States are North Kordofan, Red Sea and Darfur States. All these States are located in the drylands and their populations rely entirely on rainfed agriculture for their livelihoods. Rains amount and distribution in these States are generally becoming inadequate to secure an average to above-average rainfed crop. There are several adaptation measures and promising technologies that the agricultural sector can undertake to alleviate the effects of present and future climate changes. These technologies include early maturing-drought and heat tolerant crop varieties, planting time adjustment, seed priming and micro fertilizing, intercropping, agroforestry and water conservation practices. Dissemination of these technologies should be addressed if the vulnerability of agriculture to climate change has to be minimized. Keywords: Climate change, vulnerability, drought tolerant, heat resistant, short maturing, drylands Introduction Agriculture, including both crop and livestock production, is the main sector of the Sudan s economy. It is the major livelihood source for more than 70% of the population and about 80 percent of the labour force is employed in agriculture and related activities. It contributes about 35% to the GDP and generates around700 million US dollars annually. Sudan s agriculture has four distinct farming sectors. These are irrigated farming, traditional rain-fed farming, mechanized rainfed farming and livestock production system. The total annual cultivated area in Sudan as estimated by the Food Security Administration of the Federal Ministry of Agriculture and Irrigation is 17 million hectares. The shares of the irrigated, mechanized rain-fed and traditional rain-fed sectors in the total cultivated area are 1 Professor of Agronomy, Water Harvesting Research Institute, Agricultural Research Corporation, E- mail: arkosman@hotmail.com. 33

2 12, 35 and 53%, respectively. Main food crops grown are sorghum, wheat and millet, while groundnuts, cotton, sesame and sunflower are the main cash crops. According to Sudan s First National Communication to the UNFCCC (2003), agriculture has been identified as one of the three highest priority sectors most vulnerable to climate change. The purpose of this paper is to assess the vulnerability and impacts of climate change on Sudan s agricultural sector and explore the potential adaptation options. The information and data included in this paper was collected and built on agricultural production and productivity data, research results, Higher Council for Environment and Natural Resources and other regional and international reports and studies. Agro-climatic zones Based on rainfall and according to the ratio of humid months to arid months and length of the growing season, Sudan can be divided into five agro-ecological zones i.e. desert, semi- desert, arid, semi-arid and sub-humid. The general characteristics of each zone and the area it occupies are shown in Table 1. Agricultural activities are carried out mainly in arid and semi-arid zones in the north to sub-humid in the south. In the arid and semi-arid (a) zones, the annual rainfall is between 250 and 450 mm and traditional small-holders farming is practiced on typically goz soils or stabilized sand dunes. Gum Arabic tree is the major constituent of the vegetation and most of the gum production belt is located in these zones. In these zones, there is a considerable pressure on natural resources and desertification level is very severe, making the environment very fragile. The annual rainfall in the semi-arid (b) zone is between 450 and 750 mm. Traditional farming is practiced on clay soils, while mechanized agriculture is in the southern part of the central clay plains. This is the most important zone for rain-fed agriculture in the country. The sub-humid zone covers a small part not exceeding 10% of the country s total area and located in the far south neighbouring the Republic of Southern Sudan borders. Annual rainfall in this zone is more than 750 mm. Agriculture and forestry are the main activities. Agroecological zone Table 1. Agro-climatic zones of Sudan: general characteristics and land area occupying Annual Humid Growing rainfall (mm) Months(#) season length Area (%) (days) Desert < Semi-desert Arid Semi-arid(a) Semi-arid(b) Sub-humid Source: compiled (WSRMP 2007 Diagnostic Survey), ITTA Agro-climatic Humidity Classification. Recent climatic trends Climate change and variability is becoming a predominant phenomenon in Sudan. One of the most important anticipated effects of climate change is directly related to changes in temperature and rainfall patterns. Several recent studies have 34

3 indicated the substantial decline in precipitation and rising in temperature in several parts of the country, and global warming models predict that this trend will continue. Mohamed (1998) analysed the rainfall records from twelve meteorological stations in the Sudan located between latitudes 11 o and 20 o. Results showed that there has been a clear decrease in the annual rainfall over the last 30 to 40 years. As shown in Table 2, the annual drop in mean annual rainfall during the study period varied from about 5.0 mm in Damazine to 0.5 mm at Dongola. Additional evidence reported by UNEP (2007) have indicated that there is a long-term trend towards lower rainfall in Darfur (Table 3), while the high rainfall variability (Table 4) as indicated by the coefficient of variation in several parts of the country during the 30 - year period ( ) was reported by Osman and Ali ( 2009). Moreover, Abdalla (2012) compared two mean annual normal rainfall isohyets; namely, the 200 mm and the 500 mm, for and , and concluded that there is a remarkable shift in the rainfall belt in western Sudan. Analysis of temperature indicated that there is a clear rising in temperature in four stations representing the northern, eastern, western and southern parts of the country. Mohamed (2005) showed that during the previous decades temperature is increasing in several places from decade to decade. In the extreme northern parts, the highest temperatures vary between o C during May - June and the lowest minimum temperatures in winter vary between 2-10 C during December - January. Time series of annual rainfall and mean temperature for the period were analysed. The anomalies trends of mean annual temperature and rainfall almost show a rise in temperature and a decline in rainfall in most parts of Sudan during the last three decades of the twentieth century (Mohamed, 2005). Droughts are becoming more frequent and severe, and since the early 1970s, the country has been subjected to a series of drought shocks, the most notable are in 1984/85 and Table 2. Analysis of rainfall records from twelve meteorological stations in the Sudan Station Latitude (N) Longitude(E) Years of record Yearly drop in rainfall (mm/year) Dongola / Atbra / Shambat / Wad medani / Damazine / Gedarif / Kosti / Obeid / Sennar / Kadugli / Nyala / Source: Mohamed (1998). 35

4 Table 3. Long-term rainfall reduction in Darfur Location Average annual rainfall(mm) Average annual rainfall(mm) Reduction (mm) Reduction (%) Fashir - North Darfur Nyala - South Darfur Genana - West Darfur Source: Sudan UNEP (2007):post-conflict environmental assessment Table 4. Minimum, maximum and mean annual rainfall, and coefficient of variation at some locations during the 30 year period ( ). Location Minimum Maximum Mean Coefficient of variation (%) Gedarif Damazine Wad Medani Nyala Elfashir Elobeid Kadugli Kosti Source: Osman and Ali (2009). Projected climatic trends (temperature and rainfall patterns) Projections for East Africa (including Sudan) of annual changes in temperature and rainfall that will occur by the end of the 21 st century are presented in Table 5. These projections indicated that the median near-surface temperature will increase. However the impact of climate change will vary both in nature and in magnitude from location to location, from crop to crop and from cultivar to cultivar. Table 5. Predictions for climate change in East Africa by the end of the 21st century. Season Temperature response ( C) Precipitation response (%) Min Max Min Max DJF MAM JJA SON Annual Note: DJF = December, January and February; MAM = March, April and May, JJA = June, July and August; SON = September, October and November. Note: Temperature response indicates the projected increase in temperature over current values. Source: IPCC (2007). 36

5 Status of food security and vulnerability assessment The substantial decline in precipitation, rising in temperature and soil degradation are the most important factors causing loss in the potentiality of farming and resulting in low productivity and production and, hence making the great majority of the population vulnerable to food insecurity. Results of the study by Mohamed (2005) indicated that the degree of vulnerability differs from one region to another, with arid and semi-arid regions in the north being more vulnerable to drought than the southern part of the semi-arid and subhumid regions in the south. As shown in Table 6, the chronically vulnerable and food insecure states are North Kordofan, Red Sea and Darfur States. All these states are located in the dry lands and their populations entirely rely on rainfed agriculture for their livelihoods and there are no irrigation facilities for production of the major food crops. Rains amounts and distribution in these states are generally becoming inadequate to secure an average to above-average rainfed crop. These states can be regarded as the most vulnerable areas to climate change and variability and food insecurity and deserve particular policy attention. Over the last three decades, livelihood systems in these states have been subject to different environmental and socioeconomic challenges. The vulnerability of these areas is often exacerbated by their low levels of preparedness and capacity to undertake adaptation and mitigation measures. Table 6. Food grains deficit and levels of self-sufficiency (%) in the vulnerable states State Food grains deficit (000 tons) Average level of selfsufficiency (%) Red Sea North Kordofan North Darfur South Darfur West Darfur Source: SIFSIA Food security at household level is influenced by social vulnerability factors such as household health, composition, household head (female, child) and availability of labour and social standing in the community. Table 7 summarizes the trends in the food security situation at household level in the different states (SIFSIA. 2010). Food security at household level in the vulnerable and food insecure states i.e. Red Sea, North Darfur, West Darfur and South Darfur states indicated that 31 to 66 percent of the households are in the moderately to severely food insecure category. North Kordofan has a 54 percent of households in the moderately food insecure category and none in the severely food insecure category. Dry lands region is already among the most food insecure in the world, and climate change has the potential to aggravate the problem. In Sudan, the link between climate and livelihood is very strong, as more than 80 per cent of cultivated land is currently under rainfed agriculture and most of the population depends heavily on rain-fed agriculture and, hence, livelihoods are highly vulnerable to climate variability. Recent studies (IFPRI, 2009) indicated that by 37

6 2050 in sub-saharan Africa food crops yields will decline by up to 22% as a result of climate change. This decline in crops yields will lead to several socio-economic impacts such as more malnutrition, especially of children, increased rural-urban migration, high frequency of resource use conflicts, increased mortality rate and worsening poverty levels. Without adequate climate change mitigation and adaptation, sub-saharan African countries will suffer food unavailability, increased malnutrition, unemployment and reduced export earnings. Table 7. Household food security situation in the different states (2010) State Food Moderately food secur insecure e Severely food insecure Sennar Gedarif Kassala Blue Nile Red Sea North Darfur White Nile South Kordofan West Darfur North Kordofan South Darfur Source: Crop and Food Security Assessment Mission (2011) Current and potential impacts of climate change on agriculture and vulnerabilities Climate change is expected to impact agriculture directly by its effects on production and yields, and indirectly by affecting soil fertility, water availability, pests, flood and droughts, and socio economic impacts (policy, market, migrations and conflicts). The most important impacts are: Changes in agricultural productivity Several studies revealed that the changes in temperature and precipitation have resulted in reduced crop yields. Studies carried out by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) on disaggregated effects of climate change on sorghum yields indicated that in West Africa sorghum yield is reduced by 14% as a result of climate change (temperature and precipitation). Aune (2009) reported a reduction in time to maturity and crop yield by 19 and 56 %, respectively, as a result of mean seasonal temperature increase from 27.6 to 32.6 Celsius (Table 8). As the whole of north Sudan exhibits a typical Sahelian zone, reduction in sorghum yields are expected. This was confirmed by UNFCCC (2003) in the projected sorghum and millet yields in Sudan (Fig. 1). The projections indicate that by 2060 production in these regions will be reduced by more than 75%. 38

7 Table 8. The simulated impact of temperature increases on the mean rate of development and yield of sorghum based on historical daily climatic data ( ), Aurangabad, India Climate scenario Mean seasonal temperature (OC) Time to maturity (d) % Reduction from Current Crop yield (kg/ha) % Reduction from Current Current Current + 1O C Current + 2O C Current + 3O C Current + 4O C Current + 5O C Source: Aune (2009) Source: Sudan first National Communication under UNCCC, 2003) Fig. 1. Projected millet and sorghum yields with climate change Length and on-set of the growing season One of the anticipated effects of climate change on agriculture is the length and on-set of the growing season (LGP). The farming systems in Sudan occupy an area with a wide range of growing periods, with 61% of the surface area of the country having LGP shorter than 90 days (Table 9). Results presented in Table 9 show that climate change is likely to reduce the length of growing season in many parts of the country, as well as forcing large areas of marginal agriculture out of production. The surface areas with a short growing period (< 90 days) will increase, while the surface area with a prolonged growing period (> 180 days) will decrease. Most crops attain the highest yields in areas with prolonged LGP, thus a reduction in LGP is likely to have a negative impact on crop production and yields. In Gedarif area, Ahmed (2011) studied climate change impacts on rainfed sorghum production and the length of growing season trends during the last twenty years Decreasing trend of sorghum productivity, as well as climate change was evident. The results showed that the length of the growth 39

8 season has no consistent trend, but the average season length during the studied period was shorter than the average of the preceded period, Table 9. Average distribution of surface area (%) of Sudan under different classes of lengths of growing periods for the years 2000, 2030 and 2050 Year Surface Length of growing period (days) area (%) > Source: ASARECA (2011). Impact on wheat production Wheat plants require and must experience a period of low winter temperature (vernalization) to initiate or accelerate the flowering process and convert to the reproductive stage. Without adequate vernalization, winter wheat plants will remain vegetative or will produce very low grain yield (Hussein et al., 2005). Typical vernalization temperatures are between 5 and 10 C (40 and 50 F). In Sudan, temperature has a great impact on wheat production. The crop has to be grown in winter, but the Sudanese winter is too short. Even then, the temperature in most of Sudan is too warm to realize large yields. The growing season of wheat in the Gezira is from mid-october to mid-april, with temperatures shown in Table 10. Table 10. Wheat growing season temperatures ( C) in the Gezira Temperature Oct. Nov. Dec. Jan. Feb. March April Mean minimum Mean maximum Mean daily Only in December and January, the Gezira's mean daily temperatures are below the tolerance limit for wheat of 25.0 C. In northern Sudan, north of latitude 18.5 N, the mean daily temperatures stay below this limit from November to March but exceed it in October and April. The climate is, therefore, only moderately suitable for irrigated wheat in the north, and only marginally suitable in central Sudan. Warming presents a great challenge to wheat production. Without adequate climate change adaptation, wheat production might become not possible. The effectiveness of adaptations will depend on how well they reduce crop sensitivity to very hot days. Varieties that maximize the period of growth during favourable temperatures while maturing in time to escape excessive heat seem to be the best adaptation option. Conflict over resources UNEP (2007) listed the erosion of natural resources caused by climate change as among the root causes of social strife and conflict. Several studies have shown that decline in rainfall has resulted in scarcity in water and grazing resources, and 40

9 low rangeland productivity. Communities may find themselves in conflict over increasingly scarce food and water supplies. "The scale of historical climate change, as recorded in Northern Darfur, is almost unprecedented: the reduction in rainfall has turned millions of hectares of already marginal semi-desert grazing land into desert. The impact of climate change is considered to be directly related to the conflict in the region, as desertification has added significantly to the stress on the livelihoods of pastoralist societies, forcing them to move south to find pasture," so competition for resources, resulted from environmental degradation, is one of the driving forces and causes for tension and conflicts. Adaptation options for reducing vulnerability There are several adaptation measures and promising technologies (El-Hag and Abdalla, 2011) that the agricultural sector can undertake to alleviate the effects of present and future climate changes. Some of these technologies and their impact on yield are shown in Table 11. Table 11. Impact of some recommended climate smart technologies on crops yield Current or potential impacts of climate change (Climatic risk) Recommended adaptation options (technologies) Impact (yield Increase (%) Reduction in duration of crop period and increased occurrence of droughts and dry spells Increase in temperature and winter is too short Early drought and land degradation Increased transpiration and water requirements and decrease in water availability Erratic rainfall, frequent pest and disease attack Early maturing-drought and diseases tolerant crop varieties, alternative crops. Early maturing, heat tolerant wheat varieties, planting time adjustment (sowing dates management), agro-forestry. Seed priming and micro fertilizing. Water conservation practices through rainwater harvesting and storage, agroforestry. Intercropping systems (crops arrangement). (Alley- Increased occurrence of Agroforestry dust storms and sand cropping). blast *Collected from various authors cited in the references Conclusions and recommendations Climate change and variability and its impact in Sudan are going to be one of the major threats to food security. This change is likely to reduce the agricultural output in the long term and increase risk of hunger. The traditional rainfed

10 farming is the most vulnerable. There are already some promising technologies to reduce the negative effects of climate change. If the vulnerability of agriculture to climate change has to be minimized, these technologies should be promoted and disseminated through an efficient extension system. References Abdalla, A. K Indicators of climate change in Sudan. Proceedings of the Workshop on: Research and Adaptation to Climate Change in the Drylands of Western Sudan, El-Obeid, North Kordofan State, Sudan (A. K. Osman, ed.) December Published by: Higher Council for Environment and Natural Resources. Ahmed, K. E Utilization of Crop Simulation Model APSIM in Investigating Climate Change Effects on Sorghum Yield in Gedarif Area. M. Sc. Thesis, Sudan Academy of Sciences. Aune, J The eco-farm: an integrated approach for agricultural development in drylands, Presentation for the Eco-farm National workshop, Nazareth, Ethiopia. October 29, El-Hag, F. M. and Abdalla, E. A Technologies and innovations for adaptation to climate change and constraints to scaling-up. Proceedings of the Workshop on: Research and Adaptation to Climate Change in the Drylands of Western Sudan, El-Obeid, North Kordofan State, Sudan (A. K. Osman, Ed.) December Published by: Higher Council for Environment and Natural Resources. Hussein, H. A., Mohamed, H. A. and Ageeb, O. A. A Optimum sowing date for wheat (Triticum aestivum L.) in high terrace and alluvial soils of Northern State, ARC. IFPRI Climate change: impact on agriculture and costs of adaptation. International Food Policy Research Institute, Nariobi, Kenya. IPCC (Intergovernmental Panel on Climate Change) Mohamed I. F Assessment of the impacts of climate variability and extreme climatic events in Sudan during Mohamed, H. A Rainfall in the Sudan: trend and agricultural implication. Sudan J. Of Agric. Research, 1: Osman, A. K. and Ali, M. E. K Crop production under traditional rain-fed agriculture. A National Symposium on: Sustainable Rain-Fed Agriculture in Sudan. Organized by UNESCO Chair of Desertification Studies, University of Khartoum in collaboration with Desertification and Desert Cultivation Studies Institute November 2009, Al-Sharga Hall, University of Khartoum. Sudan's First National Communications under the United Nations Framework Convention on Climate Change Ministry of Environment & Physical Development, Higher Council for Environment and Natural Resources. Sudan UNEP Post-conflict environmental assessment. SIFSIA Food and nutrition assessment in Sudan (Analysis of 2009 National Baseline Household Survey). Sudan integrated food security information for action (SIFSIA). 42