Potato response to nitrogen sources and rates in an irrigated sandy soil
Cambouris, A.N., St. Luce, M., Zebarth, B.J., Ziadi, N., Grant, C.A., Perron, I. (2016). Potato response to nitrogen sources and rates in an irrigated sandy soil. Agronomy Journal, [online] 108(1), 391-401. http://dx.doi.org/10.2134/agronj2015.0351
Management strategies to reduce N losses to the environment from potato (Solanum tuberosum L.) production while maintaining yields depend on selecting the right N source and rate. A 5-yr (2008-2012) fi eld experiment was conducted on an irrigated sandy soil in Quebec, Canada, to examine the effect of N fertilizer source and rate on total (TY) and marketable tuber yield (MY), total plant N accumulation (vines + tubers), specific gravity, culls (unmarketable tubers), and apparent fertilizer N recovery (ANR). The treatments included an unfertilized control, and three N sources [ammonium nitrate (AN), ammonium sulfate (AS), and polymer-coated urea (PCU)] applied at four rates (60, 120, 200, and 280 kg N ha–1). The PCU was applied 100% at planting and the AN and AS were applied 40% at planting and 60% at hilling. The TY and MY increased with N rate up to 200 kg N ha–1, but were similar among the N sources. On average, total plant N accumulation and ANR were greater for AN and PCU than AS. However in 2008, when there was a greater risk of N loss due to high rainfall, total plant N accumulation and ANR were greater for PCU than AN and AS. Tuber specific gravity and culls were influenced by N rate, but the response was dependent on soil and climatic conditions. Results suggest that, under humid conditions with irrigation, a one-time application of PCU in potato production can minimize the risk of N loss without reducing tuber yield and quality.