Potato Response to a Polymer‐Coated Urea on an Irrigated, Coarse‐Textured Soil

Abstract

Controlled release fertilizers, especially polymer‐coated urea (PCU), have been shown to reduce nitrate (NO3) leaching while maintaining potato (Solanum tuberosum L.) yields, but cost has been prohibitive. A new type of PCU (Environmentally Smart Nitrogen, Agrium, Inc., Calgary, AB) is less costly than previous PCUs, but its effectiveness on potato production has not been extensively studied. A 2‐yr field study was conducted on loamy sand to evaluate the effect of this PCU on Russet Burbank tuber yield and to determine if it is economically comparable to soluble N sources. Several N rates of PCU applied at emergence were compared with two split applications of soluble N at equivalent rates. Additional treatments examined N application timing of PCU and a fertigation simulation with urea/ammonium nitrate. Petioles and midseason soil samples were collected to determine N status during the season. Overall, PCU and soluble N at equivalent N rates were found to have similar total and grade A yields and net monetary returns. The optimal N rate that resulted in maximum net returns was 251 and 236 kg N ha−1 as soluble N and PCU, respectively. Petiole NO3 concentrations were typically higher with soluble N early in the season and higher with PCU later in the season. Soil NO3 determined in samples collected in late June was found to be a better predictor of yield and potential N need than those collected in mid‐ to late July. Overall, PCU may reduce or eliminate the need for split applications of N on coarse‐textured soils.

Volatilization of ammonia in stabilized slow-release nitrogen fertilizer under controlled conditions

“…Thus, the results obtained in this work with stabilized controlled release nitrogen fertilizer does not corroborate with what is indicated by Boman and Battikhi (2007), for whom the use of slow release nitrogen fertilizer reduces the need for parceling fertilizers.By parceling the application of the nitrogen sources in three times, independently of the management type adopted (surface and incorporated), the NH 3 volatilization decreases (C7 , Table 5). Wilson et al (2009) demonstrated a reduction in the need to split N application when using coated urea, which was not observed in our study.The cumulative NH 3 volatilization values as a function of collection time were adjusted to the logistic equation [Y = a/1+e…”

Evaluation of Nitrogen Application Methods and Rates With Nutrisphere-N on Soil Nitrate-Nitrogen in Southeastern Coastal Plains

“…Wen et al (2001) reported greater N recovery from coated than regular fertilizer, because N release better matched crop N demand and uptake. Controlled release fertilizers, especially polymercoated urea helped to reduce NO 3 -N leaching in potato (Solanum tuberosum L.) and may allow reduction of split N applications (Wilson et al, 2009).…”

The IMPACT OF THE POLYMER COATING NUTRISPHERE™ IN INCREASING NITROGEN USE EFFICIENCY AND CORN YIELD

“…A two-year potato study on an irrigated loamy sand using Environmental Smart Nitrogen (ESN), polymer coated urea and a blend of urea and ammonium nitrate, found that optimum N rates were less for ESN than soluble N and potato yields under ESN were similar to those from split applied N (Wilson et al, 2009). In years with above average rainfall Wiedenfeld (1986) found that cabbage (Brassica oleracea L. Group capitata) and onion (Allium cepa L.) had increased yield, yield weight and leaf N content when grown with slow-release fertilizers, methylene urea and sulfur-coated urea, but there were no differences when rainfall was below average.…”