Sulfur

Where to suspect: Sulfur deficiencies may be suspected where there are volcanic or acid, sandy soils, and where low S fertilizers have been used for several years.

Maize, Sorghum, Millet

These crops have relatively low S needs. Stunted growth, delayed maturity, and a general yellowing of the leaves (as distinguished from N deficiency) are the main signs. Sometimes, the veins may stay green which may be mistaken for zinc or iron deficiency. However, iron and zinc hunger are more likely in basic or only slightly acid soils. Beans

Upper leaves become uniformly yellow.