B.A. McKean -
Successful growth and development of plants needs nickel. That’s partly because nickel is an essential micronutrient in the conversion of urea to ammonia and thus in the mobilization of nitrogen.
Nickel is present in all soils and only a small amount is required for urea conversion, so incidents of nickel defificiency are rare. Some plants, like the pecan tree are especially reliant on the presence of nickel.