1. 5.4 Sorghum Agronomy in Ethiopia
Dr. Ketema Belete, Haramaya University

2. Agronomic/cultural practices
1.Tillage
2. Seeding methods
3.Fertilizer application
4. Irrigation
5. Weed control
6. Plant protection

3. Why sorghum? Major cereal in moisture limited areas
One of the most drought resistant cereal ‘CROP CAMEL’
In Ethiopia – source of food, fodder, fuel and building material
Units of dry matter produced for
Crop every 1000 units water consumed
Pearl millet 3.64
Sorghum 3.46
Maize 2.88
Wheat 1.93

4. Agronomic/cultural practices
1. Tillage
 Purpose of tillage
a. Improvement of soil structure
b. Moisture conservation
c. Soil aeration
d. Root penetration
e. Weed control
F Seedbed preparation

5. Agronomic/cultural practices …
2.. Seeding methods
2.1. Planting date - rule of thumb ‘availability of moisture at planting & during the
vegetative/reproduction stage & its absence after maturity and at harvest’
2.2. Planting depth
 Depends on seed size & soil type
 2.5 to 5cm for sorghum vs 5 to 8cm for maize

6. Agronomic/cultural practices ...
2.3. Seeding rate/ Row spacing/Planting density
 Depends on variety, fertility of soil & moisture
 in Ethiopia 5 to 8 kg/ha
 in US 7.5 to 12 kg/ha
 in Ethiopia 75 x 20cm, 75 x15cm
 in US 90 x15cm (rainfed), 75x15cm (spate irr.)
 in Ethiopia to plants/ha
 in US to plants/ha

7. Plant density
In Ethiopia since sorghum is used for fodder is constantly thinned – affecting the total yield
This is due to a scarcity of other sources of fodder
If intercropped with Labla this could be overcome

8. Agronomic/cultural practices ...
3 Fertilizer application
 in Ethiopia
 N and P ( N kg/ha and P2O5kg/ha)
 DAP source of N and P at planting
 Urea source of N at knee height
 Important to have tailor-made applications
Economical under dependable rainfall & irrigation
In some spate soil natural fertility very high – would not need additional fertilizer – this would in fact even damage the crop

9. Agronomic/cultural practices ...
4 Weeding/ control of Striga
Microscopic seeds that can survive more than 20 yrs
Seeds tap into rootstems of sorghum and ‘suck’ it
If enough fertilizer/ moisture sorghum will be able to handle striga
Approach:
Use fertilizer/ moisture
Use stryga resistant varieties

10. Need to think of short duration varieties
At the moment most sorghum varieties in Ethiopia are late-maturing
This is in line with the practice of rain-fed farming and the year-round multipurpose functions of sorghum
In spate irrigated areas – especially in the lowlands where there is no supplementary rainfall - short duration varieties are more useful

11. Production Statistics of Sorghum Grain in 1998 (Source UN 1999)

12. Agronomic/cultural practices ...
5. Irrigation
- not widely used in Ethiopia for cereal production
- stored soil moisture for maximum yield is 50 to 60 cm
- preplant irrigation that wets the soil to field capacity to a depth of 2m is best – signifying the importance of adequate moisture conservation
- maximum water usage occurs
- at boot stage of the plant growth

13. Amount of water extracted from various depths by a sorghum crop during a growing season (W.M.Ross& O.J.Webster Culture and Use of Grain Sorghum)

14. Daily water use for grain sorghum
This is when crops need most water – this can also be provided from conserved moisture and capillary rise (in colder season)
In this season no irrigation or rainfall is required – it would only delay the drying of the seed and the harvest

15. Some effect but not dramatic
Interaction of Irrigation and Fertilizer (E.F.Bennett., B.B. Tucker& A. B. Maunder Modern Grain Sorghum Production)
Some effect but not dramatic

16. General points
Average yield of irrigated sorghum have increased by 82% more than non-irrigated sorghum
Moisture needed to produce acceptable yield is approximately 40 to 50 cm
Maximum yield requires 50 to 65 cm moisture
Roots of sorghum extract soil moisture from up to 2m of soil depth.

17. Water use by the plant At planting
it is needed for good seed to soil content
adequate soil moisture
proper germination temperature (min. 10oC)
the above 3 ensure good stand establishment

18. Water use by the plant (cont..)
At Seedling stage
amount of moisture taken up is low
availability of sufficient moisture is critical
root zone is less than 45 cm, thus deeper soil moisture is not needed
soil moisture is not depleted rapidly
more moisture is lost by evaporation from soil than transpiration through the crop canopy
water conservation practices to minimize soil moisture losses
residue management
narrow row spacing
proper planting date
weed control

19. Water use by the plant (cont..)
At rapid growth stage and reproduction stage (Example based on early maturing variety 150 days)
starts as of about 30 days after emergence (7 to 8 leaves stage)
pick at boot stage and bloom stage (about from 50 to 80 DAE)