Proper water management

Sorghum’s ability to extract water from great soil depth makes it better suited than most other cereal crops to growing in conditions where the water supply is limited. Although sorghum tolerates drought stress, significant increases in yields can be achieved through proper water management. Proper water management in sorghum includes catching water with trenches or ditches on slopes, applying reduced tillage and keeping the soil surface covered with mulch, reducing evaporation of water by planting wind barriers, planting sorghum early in the season, and using drought tolerant and early maturing cultivars with a growth period of about 100 days. These measures help to reduce crop water needs and limit evaporation of water from the soil.

Sorghum production in the parklands system

In the parklands system, which is common in the Sahel and Sudan zones of West Africa, trees that are considered important for various reasons are not cut when clearing land for cultivation. These tree species include Faiderbia albida, Vitellaria paradoxa and Parkia biglobosa. Annual crops like sorghum are then grown in association with these trees. Research has demonstrated that in low-fertility soils and in seasons when rainfall is limiting, sorghum grown under Faiderbia albida trees yields better than outside the tree canopies. This is due to the improved availability of soil nutrients and moisture under the trees. Faiderbia albida is leafless during the rainy season when sorghum grows and shades the soil during the dry season. Therefore, it can grow among field crops without shading them. The tree is highly drought resistant, fixes nitrogen from the air, its leaves are rich in nitrogen and can double yields of annual crops grown underneath the tree when added to the soil. Its flowers provide bee forage at the close of the rainy season, when most other local plants do not. The seed pods provide valuable feed for livestock and camel.

Use of irrigation

In tropical Africa sorghum is mainly grown as a rain-fed crop. Irrigation is only practised on a small scale in areas with intensive crop management. In some areas sorghum is grown after fields have been flooded. The total water requirements of sorghum for the entire growing season are similar to peanut and soybean. They range from 450 to 650 mm and are a bit lower than maize. Water requirements during early stages of growth are low. Thus, irrigation prior to planting is generally not useful, especially if there has been sufficient rainfall during that time. Irrigation should be planned for the later stages of growth. Water supply should be increased in line with the development of the crop and reach a peak during the change from the vegetative to the reproductive phase. Adequate soil moisture during the peak period has the most positive effect on yields. In cases where water supply is limited, irrigation should focus on avoiding water deficits during flowering to avoid early grain formation. Application of small doses of water ensures most efficient use.