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.
Foliar fertilizer is a fertilizer product which is designed to be applied directly to the leaves of a plant. A number of companies manufacture a range of foliar fertilizers, from organic products safe for use on food crops to more aggressive chemical fertilizers for ornamentals.
Soil pH determines the availability of nutrients in the soil. pH is the level of acidity or alkalinity of the soil. Maize crops grow best at a soil pH of between 5.5 and 7.3, with pH 6.0–6.5 being optimal. In this range, nitrogen, potassium, phosphorus, calcium, and magnesium are readily available.