Response of creeping red fescue (Festuca rubra L.) seed crop to timing, rate and forms of nitrogen application in the Peace Region of western Canada.

Nitrogen (N) is considered one of the major limiting factors in persistent grass seed productivity in the Peace Region of Canada. For the convenience of operation, nitrogen fertilizers are applied in the stubbles of grass seed stands in the fall season that precedes the seed harvest year. On-station and on-farm field experiments were conducted near Beaverlodge from 2014 to 2016 to evaluate the response of creeping red fescue to different timing, rates and forms of N application. Conventional urea (CU), Agrotain®-treated urea (ATU), ESN® polymer-coated urea (EPCU) and a blend of CU and EPCU were broadcast at 65 and 100 kg N ha-1 in the crop stubbles in mid-September and mid-October. Grey luvisol with acidic reaction typifies the soils at the trial sites. The growing season (May to October) was much drier in 2014 and much wetter in 2015 and 2016 than the long-term average of 30 years. Response of creeping red fescue to N application in the fall was variable over the years, signifying the weather effects on crop physiology and N dynamics in the soil. In most of the trials, N treatments produced significantly higher seed yield than the unfertilized control. However, there was no significant yield advantage of increasing N rates from 65 to 100 kg ha-1. Relative yield of mid-September or mid-October application was also variable over the years and sites. Based on both on-station and on-farm results, fall application of N stabilizer or slow release forms had no incremental effect on seed yield over conventional urea. The fescue seed crop response to N application in relation to soil quality variables will be discussed and gross-margin analysis will also be presented.