Best Fertilizer for Sorghum

An often neglected nutrient in grain sorghum is sulfur, which improves nitrogen use efficiency and is especially important as yield increases. Growers should strive to keep the nitrogen to sulfur ratio at approximately 15-to-1. In most Kenyan soils, potassium is available in adequate supply for the needs of sorghum.

"Hi, I have been growing sorghum for the past two years but my production has been really low. I have tested my soils and have good soils to grow sorghum, but production is below 1000kgs per acre. I depend on farming and right now I am unable to pay school fees for my kids in high school please help improve my production."

Kennedy Magambo

Thanks for your inquiry Magambo. Sorghum is slowly becoming a crop of greater interest than before; due to the fact that it can adapt very well in many regions of Kenya.

Sorghum can be used as food (as either grain or flour), or for brewing beer. The two are the driving force of many farmers adapting sorghum in Kenya, and the returns are good when production is equally great. Now that we have farmers who are thinking agri-business, and looking at making money from sorghum cultivation, we can now look slightly deeper into sorghum production. What nutrients are key in sorghum production, and is fertilizer use in sorghum production important?

Growth Requirement

Sorghum requires deep well-drained fertile soils. This will enhance root growth and expansion for better uptake of moisture in the soil, the best soil pH being 5.4 – 8.4. Seeding should be done when soils are moist enough to enhance uniform germination. High temperatures do affect flower initiation and development, which in turn affects overall sorghum production. Sorghum can tolerate drought conditions better than other crops due to its well-developed roots, small leaf surface area which has a waxy layer and folds inwards during high temperatures to reduce transpiration.

Fertilizer Nutrient Management

For optimal yields, it is important to understand the requirements of the crop. Sorghum requires several key nutrients for maximum productivity. These are Nitrogen(N), Phosphorus(P), Potassium(K), Sulphur(S), Magnesium(Mg), Zinc(Zn), Calcium(Ca) and to some extend Manganese(Mn) and Copper(Cu).

Farmers should apply NPK fertilizer with the at least six combinations of the above nutrients (including the NPK) for maximum production. NPK fertilizers with rations (N=20-24, P=9-11.5, K=4.5-7) including S, Mg, and Zn give the best combination ratio for sorghum production.

Fertilizer application for the above NPK is best done in two splits for better yield production. The recommendation would be to do a rate of 75kg per acre at planting and 50kg per acre at topdressing. Topdressing fertilizer should be applied knee-high.

In every crop planted, please ensure you use certified seeds, and good agricultural practices in order to realize the maximum benefit of investing in high-quality fertilizer. Production for sorghum varies with variety ranging from 8T for Gadam, and 12t for Serena.

I wish you the best as a farmer, and please invite me for a cup of uji made from sorghum after the harvest.

Peter Wekesa

Senior Agronomist, Yara