## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Heedlifier**} & \multicolumn{2}{c}{**1000 Crain Weight (g)**} & \multicolumn{2}{c}{**Protein (\%)**} & \multicolumn{2}{c}{**SDS Sedimentation Test**} & \multicolumn{2}{c}{**SDS/Protein Index**} & \multicolumn{2}{c}{**Wholesional Yellowness**} \\ \multicolumn{2}{c}{**Gh(m)**} & \multicolumn{2}{c}{**Standard**} & \multicolumn{2}{c}{**Mean**} & \multicolumn{2}{c}{**Standard**} & \multicolumn{2}{c}{**Mean**} & \multicolumn{2}{c}{**Standard**} & \multicolumn{2}{c}{**Standard**} & \multicolumn{2}{c}{**Mean**} & \multicolumn{2}{c}{**Standard**} \\ \multicolumn{2}{c}{**Mean**} & \multicolumn{2}{c}{**Error**} & \multicolumn{2}{c}{**Mean**} & \multicolumn{2}{c}{**Error**} & \multicolumn{2}{c}{**Mean**} & \multicolumn{2}{c}{**Error**} & \multicolumn{2}{c}{**Mean**} & \multicolumn{2}{c}{**Error**} & \multicolumn{2}{c}{**Mean**} & \multicolumn{2}{c}{**Standard**} \\ \hline N Level, Ng N & 0 kg N ha\({}^{-1}\) & 78.85 a & 0.13 & 57.94 b & 0.42 & 9.20 a & 0.16 & 11.31 a & 0.17 & 1.25 b & 0.02 & 14.23 a & 0.06 \\ ha\({}^{-1}\)(A) & 20 kg N ha\({}^{-1}\) & 80.80 b & 0.13 & 58.08 b & 0.42 & 11.09 b & 0.16 & 11.29 a & 0.16 & 10.2 a & 0.02 & 14.52 b & 0.06 \\ [PERSON] et al. [45] studied the impact of three diazotrophic endophyticytic bacteria, IAC-AT-8 (_Azospirillum brasilense_), IAC-HT-11 (_Achromobacter insolitus_), and IAC-HT-12 (_Zoogloea ramigena_), on the metabolism, physiology, and growth of wheat (_Triticum aestivum hard_ L.) plants under different levels of nitrogen urea: 0%, 50%, and 100% of the recommended N-fertilizer rate. They found increases in glutamine synthetase (GS) activity in 0% and 50% of the fertilizer (which also exhibited an increment in nitrate reductase--NR--activity) in plants colonized by _A. insolitus_. The GS activity is studied as an auxiliary parameter for the evaluation of N utilization; its increase is related to increments of N content and dry weight of shoot, root, and/or grain. As previously mentioned, recent works by our group have demonstrated a positive effect of the BC on wheat yield at total N concentrations of 123-225 kg N ha\({}^{-1}\) in the soil, maintaining good grain quality [5], emphasizing significant differences in inoculated treatments vs. their uninoculated controls (fractionating N: 33%, 33%, and 33% at each fertilization event). Also, increases in nitrogen-use efficiency (14 and 12.5%) at two consecutive agricultural cycles 2018-2019 and 2019-2020 were observed when the N fertilization dose was 120 kg N ha\({}^{-1}\) (uninoculated and inoculated; NUE of 39.3 and 36.3% in 2018-2019; 46.9 and 42.8% in 2019-2020) vs. the total N rate fertilization of 240 kg N ha\({}^{-1}\) (both uninoculated and inoculated; NUE of 25.3 and 26.3% in 2018-2019; 34.4 and 21% in 2019-2020) [5]. It is worth noting that fertilization at planting, measured at the tillering stage (Figure 3), showed a very low NUE, with values no higher than 11.9 \(\pm\) 4.6%, and as low as 3.1 \(\pm\) 0.6%. During this stage, more N was derived from the soil (from 11.5 \(\pm\) 2.9% to 23.9 \(\pm\) 4.7%). This effect could be attributed to the fertilization method, where urea is surface-applied in bands  
Figure 3: Effect of nitrogen dose and the inoculation of a bacterial consortium on nitrogen-use efficiency (\({}^{15}\)N) at different durum wheat growth stages. 1 atom % \({}^{15}\)N excess labeled urea was applied at planting (30%), 45 days after sowing (60%), and 80 days after sowing (10%) at two different rates of N, with and without the inoculation of a bacterial consortium (BC) formed by _Bacillus cabrialesii_ subsp. _cabrialesii_ TE3\({}^{T}\), _Pristia megaterium_ TRQ8, and _Bacillus paralichemiformis_ TRQ65. Total N applied up to that stage’ is the sum of N applications per hectare before the date of the collection of that sample in that stage of development; \"Nitrogen-use Efficiency’ is the percentage of the applied nitrogen fertilizer that was recovered by the crop.