AS/AN treatment is split application with 1/3 of total N applied at emergence as ammonium sulfate and incorporated by hilling cultivation with the remaining 2/3 applied as ammonium nitrate at tuberization and immediately watered in. ESN was all applied in one application at emergence and similarly incorporated by the hilling cultivation. Yield values are marketable yield and are means of two years. Source: Dr. M. Ruark, Univ of Wisconsin, Agron. J v. 106.
Potatoes require careful management of relatively high nitrogen (N) rates. They are a shallow-rooted crop often grown on sandy soils with potential for nitrogen (N) leaching beyond the root zone and into groundwater. ESN has repeatedly been shown to produce greater potato yields with fewer applications, reduce N leaching, and increase profits. In this Wisconsin study, one ESN application produced yields similar to a conventional split application and reduced leaching losses.
One ESN application produced yields similar to conventional split application of ammonium sulfate and ammonium nitrate saving application time and money.
ESN application at emergence at 250 lbs N/ac increased potato profit by $83/acre over the split application.
A reduced rate of ESN (200 lbs N/ac) maintained yields similar to conventional split application and increased profits by $74/acre.
ESN maintained lower groundwater nitrate concentrations than AS/AN split application.
