Objective:

To evaluate nitrogen use response of spring wheat varieties on yield and quality.

Personnel:

J.A. Torrion, R.N. Stougaard, L. Talbert, J. Garner, B. Bicego-Almeida

Methods:

Eight spring wheat cultivars, including four soft white and four hard red, were grown under five nitrogen (N) levels as a split plot, randomized complete block design with four replications. The N levels represent the whole plot factor and the eight spring wheat varieties were the sub plot factor. The five N treatments included an unfertilized check, 40, 80, 120, and 160 lbs/A added N. The check had an initial 98 lbs/A soil N. The resulting total N of the five treatments were 98 (check), 138, 178, 218, and 258 total lbs N per acre. Supplemental irrigation was applied to keep soil moisture from falling below 50% of the plant available water. Total irrigation applied was 5.7”.

Summary:

N treatment was significant for protein and recorded a maximum protein response at 138 total N/A (Figure 1). Protein ranged from 10.45 percent for UI-Stone to 16.30 percent for Egan (Figure2, Table 2). All other agronomic traits showed no significant difference for N treatment (Table 2). Note that the check (no added N) had high initial N content. Yield and other traits were significant for the variety main effect. On average, yield of soft whites were higher than hard reds (Figure 3). Within hard red market class, Egan yield was significantly depressed from McNeal, but equivalent with Solano and Vida. Egan consistently had high protein. Refer to Table 3 for yield response - bushels produced per lb of N.

Table 1. Materials and Methods.

Seeding Date: 4/21/16 Harvest Date: 8/25/16
Julian Date: 112 Julian Date: 238
Seeding Rate: 25 plants/sqft Previous Crop: Alfalfa
Tillage: Conventional Irrigation: Yes
Soil Type: Fine Sandy Loam Soil Test: 57-10-95
Fertilizer: ___-63-148 Herbicide: 5/17/16
Huskie 11floz/A + Axial 16/4 floz/A
Fungicide: 6/23/16
8.2 floz/Prosaro 		Insecticide: 6/27/16
1.92 floz/A Warrior II

 

figures 1, 2, 3

Table 2. Nitrogen effects on irigated spring wheat agronomic performance

Cultivar HT in LOD % YLD bu/A PRO % TWT lb/bu TKW g FN sec PM days MC %
                                                             98 lbs/A Nitrogen (no added fertilizer)
Alpowa 35.0 7.5 137.9 11.15 64.3 43.5 377 100 10.9
Alturas 36.8 5.0 155.8 10.75 63.4 42.7 295 103 10.9
Penewawa 35.5 2.5 133.1 10.95 63.6 42.1 331 99 10.8
UI-Stone 34.5 0.0 143.8 10.45 63.2 42.3 308 100 11.0
Egan 37.8 0.0 125.2 15.38 62.5 43.0 489 99 10.5
McNeal 37.3 0.0 121.8 14.08 63.3 45.7 487 102 10.7
Solano 28.3 0.0 127.6 15.15 63.8 39.3 398 102 10.9
Vida 34.0 1.3 131.1 14.13 63.1 42.2 355 103 11.1
                                                                             138 lbs/A Nitrogen
Alpowa 35.0 25.0 128.1 11.55 64.0 43.3 341 102 11.2
Alturas 38.0 0.0 139.4 10.98 63.1 41.5 289 103 11.0
Penewawa 35.0 7.5 128.6 11.30 63.2 41.2 329 100 10.9
UI-Stone 34.0 20.0 141.8 10.85 62.8 41.9 255 102 11.1
Egan 35.8 10.0 121.9 16.30 62.2 42.1 478 101 10.7
McNeal 39.0 12.5 131.6 14.48 63.4 45.7 464 102 10.9
Solano 30.0 0.0 127.9 15.35 63.6 44.9 407 103 11.4
Vida 36.0 7.5 123.8 14.33 62.8 42.3 347 104 11.9
                                                                            178 lbs/A Nitrogen
Alpowa 35.8 2.5 131.8  11.90  64.2  43.8  357  101  11.0 
Alturas 37.3  5.0  139.3  11.00  63.3  41.8  277  103 11.1 
Penewawa 35.0  10.0  130.8  11.40  63.5  41.5  307  102 10.9 
UI-Stone 33.5  25.0  146.9  10.85  63.0  41.0  291  101 11.4 
Egan 36.8  0.0  109.5  16.40  62.4  42.0  491  101 10.7 
McNeal 37.0  1.3  130.1  14.83  63.3  45.0  492  102 10.8 
Solano 28.5  0.0  113.7  15.85  63.6  46.0  400  103  10.9 
Vida 34.5 1.3  127.0  14.83  62.9  42.3  346  102 11.5 
                                                                            218 lbs/A Nitrogen
Alpowa 34.5 17.5  133.6  11.68  64.2  44.1  360  100 10.9 
Alturas 37.0  12.5  140.0  10.85  63.2  42.0  282  102  11.1 
Penewawa 33.5  5.0  118.0  11.20  63.2  42.7  328  101  10.8 
UI-Stone 34.5  1.3  141.7  10.65  62.9  42.0  301  99  10.8 
Egan 38.8  0.0  127.0  16.28  62.4  42.0  477  100  10.6 
McNeal 39.3 0.0  128.1  14.73  63.3  46.1  440  102  10.9 
Solano 29.3  0.0  127.0  15.50  63.6  45.5  396  102  11.4 
Vida 35.0  0.0  138.3 14.53  62.8  41.6  344  104  11.9 
                                                                             258 lbs/A Nitrogen
Alpowa 35.5 5.0  123.5  11.83  64.1 45.2  346  102  11.2
Alturas 37.5  10.0  137.2  11.10  63.3  42.6  274  103  11.1 
Penewawa 34.5 27.5  133.5  11.50  63.0  42.8  299  101  11.0 
UI-Stone 34.3 17.5  120.2  10.70  62.9  39.6  291  101  11.1 
Egan 37.0 2.5  127.5  16.28  62.4  40.0  461  101  10.7 
McNeal 37.8  2.5  135.5  14.95  63.3  46.4  473  103  11.2 
Solano 29.8  0.0  119.7  15.73  63.3  44.7  383  105  11.6 
Vida 34.3  25.0  124.5  13.70  62.4  41.5  348  105  11.9 
LSD ns  ns  ns  0.5  ns  ns  ns  ns  ns 
Pr>F (0.05) - N 0.8506  0.6023  0.6953  0.0441  0.3877  0.8374  0.3642  0.6523  0.1937 
Pr>F (0.05) - V <0.0001  0.0266  <0.0001  <0.0001  <0.0001  <0.0001  <0.0001  <0.0001  <0.0001 
Pr>F (0.05) - NxV 0.6691  0.2489  0.1062  0.7361  0.8687  0.0041  0.2922  0.4980  0.0853 

FN: falling number: HT: height; LOD: lodging; MC: moisture content; PM: physiological maturity; PRO: protein; TKW: thousand kernel weight; TWT: test weight; YLD: yield; V: variety

Table 3. Nitrogen productiviey (Bushels per lb N) of irrigated soft white spring wheat (SWSW) and hard red spring wheat (HRSW)

Vareity             Total N lbs/A
  98 138 178 218 258
                  SWSW
Alpowa 1.34 0.95 0.74 0.60 0.51
Alturas 1.45 1.03 0.80 0.65 0.55
Penewawa 1.31 0.93 0.72 0.59 0.50
UI-Stone 1.42 1.01 0.78 0.64 0.54
Average 1.38 0.98 0.76 0.62 0.52
                   HRSW
Egan 1.25 0.89 0.69 0.56 0.47
McNeal 1.32 0.94 0.73 0.59 0.50
Solano 1.26 0.89 0.69 0.57 0.48
Vida 1.32 0.93 0.72 0.59 0.50
Average 1.29 0.91 0.71 0.58 0.49