A Golf Course Putting Green Micronutrient - Nickel, It's Significance and Potential.

Nickel (Ni) has been established as an essential micronutrient for crops with its major function being an important cofactor of urease in the hydrolysis of urea.  A soil survey has been conducted on warm-season putting greens where urea is the major N source, which reveals soil Ni concentrations less than 1 mg kg^-1.  In addition, results indicate iron (Fe) and other cations in soils may generate an antagonistic effect for Ni use efficiency of turfgrasses receiving urea fertilizer during the growing season.  Our group has identified additional Ni increased urease activity and total amino acid contents in two warm-season turfgrasses under greenhouse conditions.  Also, preliminary results of an on-going field trial of a bermudagrass putting green with urea and Ni fertilization demonstrate similar results. Furthermore, urea metabolism in turfgrasses is a new research topic as a part of nitrogen metabolism with the impact of Ni on glutamine synthetase (GS), both in greenhouse and field conditions, not identified.  Greenhouse turfgrass Ni toxicity symptoms were also first reported by our group.  The data collected recently reveal a possible soil Ni deficiency in sand based root zones, and plant health and N metabolism might benefit from added Ni nutrition.   More research is needed to study the competition of Ni and other cations in the soil, as well as identifying the soil and plant Ni levels needed for optimal N metabolism in turfgrasses.