STATUS, PRIORITIES AND NEEDS FOR SUSTAINABLE SOIL MANAGEMENT IN SUDAN

Mohamed Ahmed Salih

Land and Water Research Centre, ARC, Sudan

Workshop on Global Soil Partnership in Near East And North Africa

17 - 19 June 2014 Amman, Jordan

SUDAN

* Sudan is one of the largest African countries. * It covers about 13 degrees latitudes crossing a range of climatic zones from semi dry climate to bare desert.

SUDAN

Over 84 m ha of suitable land for agric. production Only 25% or less of land is under use now

Variety of water resources, the river Nile and its

tributaries, rain fall and huge underground water reserves

Variety of ecological zones that contribute in providing suitable conditions for selection and growing of wide range crop species.

* 1- Desert Climate * North of Khartoum, with low rainfall, less than 250 mm

with very scanty vegetation. * 2 - ARID ZONE CLIMATE * High summer temperatures * Rainfall ranging from 225-400mm. * Sparse acacia trees ad grasses. *3 - SEMI-ARID CLIMATE *High summer temperatures *Rainfall 400- 750 mm. *Savannah trees and long grasses

HIGHLANDS CLIMATE

Jebel Mara and Red Sea hills Semi Mediterranean climate

1- Desert Soils * In the north western desert, the soils are mainly

Aridisols , flat, formed insitu, coarse textured, with weakly developed diagnostic horizons.

In the eastern desert the soils are Aridisols with coarse texture, active wind erosion, no detailed studies were made

2 - Riverain Soils:

Recent Terrace Soils : Recent alluvial deposits, dark gray, medium texture,

platy structure, mildly alkaline, non-saline, non-sodic, belongs to Entisols order.

Old Terrace Soils: Old soils , deep, salts seen on surface, saline sodic ,

Aridisols. Soils of Tokar delta with varying textures from fine,

medium to coarse, Classified as Entisols

Clay Soils Of Central Sudan: Agriculturally, the most important soils in Sudan * They extend from west of Kassala through central

Sudan up to southern Kordofan. They are cracking soils

They encompass major irrigated agric. Schemes

including Gezira, Rahad , New Halfa , sugar plantation projects ,traditional and mechanized rain fed agriculture

1 - Gezira Clayey deposits. Alluvial deposits originating from the Ethiopian highlands, they are broad flat clay

plains, high CEC, high clay %, high buffering capacity, low N, OM and Available P..

2 - Butana Clay Plain: Formed in situ from the basement complex and

filled in materials from the surrounding hills

Dinder-Kenana Plains: Alluvial deposits of the Blue Nile, formed from the

weathering of the basement complex Heavy texture soils, with very high clay content,

deep, widely cracking, calcareous, non-saline and non-sodic .

Gedarif-Gallabat : Formed insitu, deep, cracking clays, with inclusions

of Azaza , ( red sealed surface soils) Alfisols ) .

Jebel Merra and Red Sea hills. Intersected by valleys and water courses with

shallow soils .

Volcanic ash soils of Jebel Merra.

Weighted average for 0 = 100 cm depth

Weighted average for 0 -30 cm depth

Soil Name Land form

Clay %

ESP%

CaCO3 %

EC ds/m

K Cmol/kg

CEC Cmol/kg

N% O C% PH Desert and semi desert

plains 31 7 2.9 6.9 2.5 35 0.015 0.07 8.3 Damar

33 20 1.6 2.1 0.9 32 0.024 0.06 8.4 Atbara

54 20 3 2.6 0.75 50 0.01 0.36 8.1 Gezira Arid clay plains Properties of Some Arid Zones Soils

75 3 0.3 0.3 0.5 75 0.11 0.4 7.5 North Gedaref

0.5 0.6 3 0.2 0.23 0.2 0.011 0.17 7.5 N \State Sand sheets and dunes 7 1.1 0 1.1 0.45 6 0.009 0.10 7.7 N kordofan

and N darfur

pH أسم التربة paste

0.C. %

N %

P mgkg-1

K cmolkg-1

ESP% 0-30 cm

Zn Mgkg-1

Cu mgkg-1

Fe mgkg-1

Mn mgkg-1

7.81 8.38 1.13 0.470 5.91 1.120 2.70 0.048 0.333 8.20 ود العطایا

6.0 11.14 1.33 0.112 4.9 1.180 3.07 0.046 0.375 8.40 أم تریبات

5.79 10.17 1.13 0.395 11.42 1.010 0.77 0.039 0.353 8.08 ود الحداد

5.09 10.29 1.03 0.170 11.1 0.934 3.55 0.038 0.307 8.10 الرمیتاب

4.91 2.72 1.01 0.190 13 0.960 3.54 0.040 0.415 8.10 الجموعیة

ND ND ND ND 11.4 0.994 3.32 0.037 0.375 8.04 السلیمى 5.03 9.95 0.89 0.195 14.9 0.870 3.32 0.034 0.324 8.20 جبار

4.44 10.22 1.20 1.610 11.8 0.790 3.04 0.037 0.342 8.00 الدومھ

4.68 0.86 10.06 0.054 6.44 0490 3.73 0.037 0.506 8.05 الدوحة

Some Soil Characteristics of Central clay plains Areas

Source : Soil survey Report (Gezira – south group)

Land form Soil Name Weighted average for 0 -30 cm depth

Weighted average for 0 = 100 cm depth

Desert and semi desert plains

PH O C%

N% CEC Cmol/kg

K Cmol/kg

EC DS/M

CaCo3 %

ESP%

Clay%

Damar 8.3 0.07 0.02 35 2.5 6.9 2.9 7 31

Atbara 8.4 0.06 0.02 32 0.9 2.1 1.6 20 33

Arid clay plains Gezira 8.1 0.36 0.01 50 0.75 2.6 3 20 54

North Gedaref 7.5 0.4 0.11 75 0.5 0.3 0.3 3 75

Sand sheets and dunes

N/ State 7.5 0.17 0.01 0.2 0.23 0.2 3 0.6 0.5

N kordofan and N Darfur

7.7 0.10 0.01 6 0.45 1.1 0 1.1 7

Land form Soil Name USDA 1990

Desert and semi desert plains

Order Great group

Damar ARIDISOLS Typic Haplocambids

Atbra Vertic Haplocamibids

Arid Clay plains Gezira VERTISOLS Sodic Haplostert

N/Gadref Aridic Haplostert

Sand sheets and dunes

N/State ENTISOLS Typic Torripsamments

N/Kordofan .N/ Darfur

Typic Torripsamments

Land form Soil Name Suitability Classification Desert and semi desert Damar S3tsg Topography,

Salinity and surface gravels

Atbra S2eaf Sodicity, erosion and feitywrtil

Arid clay plains Gezira S2vf Vertisolic characteristics and fertility

N/ Gadaref S2vf Vertisolic characteristics and fertility

1 – Drought and Desertification

2 – Salinity

3% of Sudan area was converted to desert 64% of Sudan area is threatened by desert creep

Indicators of land degradation were manifested in –prevalence of wind erosion, water erosion due to

soil compaction and surface runoff, low vegetative cover etc…

1- low rain fall and prolonged drought spells

2 - Human factors :

- Forest tree cutting for agriculture - Over grazing - Mono-cropping and lack of crop rotation

Saline soil in Sudan amounts to 23% of its area

(Berima, 2000)

Low precipitation and high evaporation are among factors that lead to salts accumulation

In affected areas

Limitation Remedy Topography Leveling/ pivoting Salinity Leaching (LR) ,Tolerant crops Sodicity Gypsum and leaching (GR ,LR ), Tolerant

crops Erosion Shelter belts , soil conditioners ,etc Fertility Fertilization , organic manning , rotation Moisture Watering by proper migration method ) Vertisolic Manu ring , plowing,etc. Wetness Drainge , sutable crop (eg .rice ) Physical Plowing ,sub soiling , chiselling ,manuring

The major agric. soils are low on OM. Total N,

available P most of the micro nutrients

Management strategies include: Crop rotation with a legume component Addition of fertilizer both chemical and

organic

Fertilizer 000 Tonnes

N (urea ) 54.3

P₅ O₂ (TSP) 11.1

K₂ O (Potassium Chloride)

3.8

Year Urea USD/Tonne TSP USD/Tonne

1995 73.63 54.02 1996 96.45 146.37

1997 157.29 170.69

1998 111.72 159.86

1999 116.72 179.36

2000 150.99 173.40

2001 87.58 174.61

2002 139.47 162.09

2003 152.53 170.86

2004 215.54 229.27

2005 209.96 260.32

Source: MOA

Crop1N-2N Dose Locality Cotton 86 kg N/ha Gezira Wheat 86 kg N+43 kg

P2O5/ha Gezira+North Sudan

Sorghum 43 kg N- 86 kg N.ha

Gezira-Rainfed area

Sugar cane 172 kg N/ha Kenana Rice 129 kg N+43 kg

P2O5/ha White Nile Gezira

Maize 86 kg N +43 kg P2O5.ha

Irrigated sector

Sunflower 43 kg N- 86 kg N/ha

Rain fed - Gezira

Level of Soil Survey

of Total Surveyed Areas

% of Sudan Area

Detailed Survey

1 0.28

Semi-detailed 5% 2

Reconnaissance 6% 2.7

Explaratory 88% 36.4

total 100 41.3

**Soil Map of Sudan at 1:250,000 *Development of Soil Fertility Maps *Need to develop climate change adaptation and

mitigation technologies *Development of benchmark Soils as a base for soil

research *Combating Desertification

Develop appropriate crop rotations which improve soil fertility and soil conservation;

Develop, improve and adapt methods for cost effective use of: Organic fertilizers; mulching to improve water retention; minimum tillage and Cultural practices.

* Capacity Building , for both Human and Laboratory

equipments *Land Suitability maps in climate change perspective *Development of a Awareness on the importance of

regulating the use of soil and water resources and the critical role they played in human life

Thank You