When Less Is More: Improving Nitrogen Use Efficiency In Potatoes On Sandy Soils.

Timing and the extent of nitrogen availability is crucial to maximizing plant productivity. In the case of potato production systems on sandy soils, ensuring nitrogen availability is an elusive goal due to the high risk of nitrate leaching. Controlling the rate of nitrogen release through the use of chemical or physical barriers, such as urease or nitrification inhibitors, or polymer coating, can aid in matching nitrogen availability with plant demand. Two experiments conducted on sandy soils of Central Wisconsin over three years show that the rate of nitrogen applied is secondary to timing of nitrogen availability. This was demonstrated by higher nitrogen use efficiency and higher potato tissue and tuber N concentrations on plots fertilized with Environmentally Smart Nitrogen ™, compared to ammonium sulfate/ammonium nitrate treatment traditionally used in potato systems.