Thesis (M.S., Plant, Soil and Entomological Sciences)--University of Idaho, June 2015 | Potato (Solanum tuberosum L.) growth rate increases with increased soil and air temperatures, therefore increasing nitrogen (N) demand. A relatively new PCU may meet this demand in a more timely and efficient manner through temperature-controlled release of N. If so, this PCU may have the potential to increase yield and tuber quality, while minimizing gaseous and leaching N losses and increasing nitrogen use efficiency (NUE). Russet Burbank potato was grown in three locations near Aberdeen and Blackfoot, Idaho, USA in 2006 and near Aberdeen in 2007 with five rates of N (0, 33, 67, 100, and 133%) applied as either split-applied urea (similar to grower standard practices), urea applied all at emergence, or PCU applied all at emergence. The PCU-fertilized treatments produced higher US No. 1, marketable, and total tuber yields than the other fertilizer treatments and the unfertilized control. There was also a trend for increased tuber size, for PCU fertilized treatments. Increased NUE was demonstrated with increased yields per unit of N applied when using PCU.