Advanced Agronomic Practices to Maximize Feed Barley Yield, Quality, and Standability in Alberta, Canada. II. Responses to Supplemental Post‐Emergence Nitrogen

Abstract

Agronomic solutions such as supplemental post‐emergence N may increase yield of feed‐barley grain. Grain yield, grain N yield, and grain protein generally increased as post‐emergence N rate increased. Largest grain yield increases occurred in environments with >300 mm of growing season precipitation. Yields decreased when N was applied as urea ammonium nitrate in hot and low‐precipitation conditions. There were no adverse negative effects to maturity, lodging, or grain quality in ‘Amisk’ feed barley. Small yield gains and decreasing feed barley (Hordeum vulgare L.) acreage in Alberta may be addressed with agronomic solutions. Field experiments were conducted from 2014 to 2016 at 3 irrigated and 11 rain‐fed environments in Alberta, Canada, to determine the effects of supplemental post‐emergence N on ‘Amisk’ feed barley growth, grain yield, and grain quality. At the time of seeding, urea N was applied at rates suitable for targeting average yield potential in each environment. Just prior to BBCH 30 (beginning of stem elongation), this was supplemented with additional 0, 34, and 68 kg N ha−1 in the form of undiluted urea ammonium nitrate (UAN), and 34 kg N ha−1 with the urease inhibitor N‐(n‐butyl) thiophosphoric triamide (NBPT). In most environments, grain yield, grain N yield (grain yield × percentage grain N), and grain protein increased with post‐emergence N rate. The largest positive grain yield responses (up to 19%) usually occurred in environments with more than 300 mm of growing season precipitation. Grain yield and grain N yield were significantly reduced when post‐emergence N was applied in high temperatures with low precipitation. Post‐emergence N increased height, but did not markedly change lodging or days to maturity. The grain quality parameters of test weight, starch, and fiber had minor responses to post‐emergence N application. The addition of NBPT to post‐emergence N had little effect on any response variables. Supplemental post‐emergence N provided an agronomic solution for increasing feed barley grain yield, but consistent increases were limited to irrigated or high precipitation environments.

Assessing Effects of Agronomic Nitrogen Management on Crop Nitrogen Use and Nitrogen Losses in the Western Canadian Prairies

“…The geo-spatial variations of modeled dryland barley grain yields and N uptake across different soil groups and climates in Alberta during 2011-2015 matched reasonably well against observed variations in barley yields and N uptake reported across Alberta (Figures 6-8) (McKenzie et al, 2004;Anbessa and Juskiw, 2012;Perrott, 2016). However, modeled barley yields FIGURE 6 | (A) Spatial distribution of observed and modeled dryland or rainfed barley grain yields across Alberta's agricultural areas averaged over the simulation period (2011-2015).…”

“…These phenomena were not accounted for in these simulations since these simulations included only welldrained, mid-slope landforms, which tend to be higher yielding. Although the modeled dryland barley grain yields were larger than the AFSC data, the modeled grain yields and grain N uptake were well within the ranges of long-term experimental data on barley grain yields (i.e., 4,300-6,900 kg ha −1 year −1 ) and N uptake (i.e., 81-131 kg N ha −1 year −1 ) across brown, dark brown, black, and gray soils of southern and central Alberta (Figures 7, 8) (McKenzie et al, 2004;Anbessa and Juskiw, 2012;Perrott, 2016).…”

Winter cereal responses to dose and application timing of trinexapac‐ethyl

“…Other studies also observed minimal responses to some stem structures. For example, application of Manipulator also improved the grain yield and plant structure without notable changes to plant height and lodging in barley ( Hordeum vulgare L.) (Perrott et al., 2018). For winter cereals and barley, uptake of a PGR seemingly initiates partition changes in carbon allocation to reproductive parts of the plant over the stem wall.…”

Efficiency of fall versus spring applied urea‐based fertilizers treated with urease and nitrification inhibitors II. Crop yield and nitrogen use efficiency

“…However, the conserved N translated into an increase in yield, N uptake, and NUE in CSL but not in PCL. The lack or inconsistency of the effect of NBPT (with or without NI) on the yield of small grains is common on the Canadian prairie, as reported in the previous studies of Grant (2014), McKenzie et al (2010), and Perrott et al (2018, who found no effect of NBPT on grain yield from surface-applied urea. The lack of any effect of NBPT on the yield and N uptake of small grains is because the N conserved with the use of NBPT is relatively small compared with the influence of applied N fertilizers and soil N (residual nitrate + mineralization) on the yield of wheat and canola.…”

“…(2010), and Perrott et al. (2018), who found no effect of NBPT on grain yield from surface‐applied urea. The lack of any effect of NBPT on the yield and N uptake of small grains is because the N conserved with the use of NBPT is relatively small compared with the influence of applied N fertilizers and soil N (residual nitrate + mineralization) on the yield of wheat and canola.…”