ABSTRACT
Nickel (Ni) was the last to be added to the list of essential nutrients for plant growth. Its importance for higher plants was established in the 1980s (Welch 1981; Eskew, Welch, and Cary 1983), using the soybean as a test plant. Although Ni deficiency in wheat, potatoes, and beans was observed in 1945 (Alloway 2008), its importance was not conclusively demonstrated until 1987 (Brown 2007). Micronutrient deficiency in soils is due to low natural levels. In addition, micronutrient deficiencies are due not only to low contents of these elements in soils but more often to their unavailability to growing plants (Brady and Weil 2002). Soil types and properties commonly associated with Ni deficiency are sandy texture, high soil pH (>7.0), high CaCO3 content (>15%), and calcareous soils.
