Optimizing N fertilizer applications involves maximizing N use efficiency (NUE) while minimizing losses but depends on complex interactions of crop, soil, weather, and management practices. One approach may be to use controlled-release fertilizer that synchronizes N availability with plant demand. A field experiment at two Ontario locations from 2007 to 2009 compared split-applied ammonium nitrate (ANs) to preplant-applied poly-coated urea (PCU) and soluble N at a ratio of 75:25 at five N rates on late-season storage cabbage (Brassica oleracea L. var. capitata). Maximum yield and profit margins were obtained at an average of 286 and >300 kg N ha-1, but few differences among sources were observed. Compared with ANs, PCU did not affect plant N content, nor did PCU reduce soil nitrate or NUE, which indicates little differences in risk of environmental N losses between N sources. Dissolution from mesh bags indicated 5%–25% of various PCU formulations remained by harvest but 5%–10% remained by spring, which suggests conservation over the winter, a need to synchronize N release with crop uptake, and partially explains the lack of treatment differences. From agronomic, economic, and environmental perspectives, the tested PCU treatments for cabbage production in a humid, temperate climate were equivalent to the standard practice.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.