Main Factors Influencing Yellow Field Pea Protein Content in Nebraska

Main Factors Influencing Yellow Field Pea Protein Content in Nebraska

Yellow field peas (Pisum sativum L.) recently gained popularity across Nebraska due to their rotational benefits and increase in consumers' demand for plant-based alternatives to meat and dairy products. Protein isolate manufacturers have a special interest in grain with high protein content as it reduces the amount of raw material being processed and increases the efficiency of the protein isolation process (Figure 1).

The objective of this project was to identify the impact that location, variety selection, irrigation, tillage and fertility programs have on yellow field pea protein content in Nebraska (Figure 2).

Figure 1. 2017 USA Pulse Growing Regions by County (left); Field peas grain processing chart from plant to grain to protein, starch and fiber isolates (right).
Figure 2. Field experiments including irrigated field pea variety evaluation (left), tillage (center) and fertility programs (right) were conducted during 2019 growing season at Grant, NE

2019 grain protein studies

Four field experiments were conducted at Henry J. Stumpf International Wheat Center near Grant, NE to evaluate yellow field pea grain yield (t/ha) and protein content (%; Near-Infrared (NIR) Spectroscopy - method):

  1. Variety evaluation of 20 yellow field pea varieties at 3 sites:
    • Grant, NE dryland – non-replicated strips
    • Grant, NE irrigated – 4 reps
    • Mead, NE dryland – 4 reps
  2. Irrigated study at Grant, NE had 3 treatments using field pea variety Durwood (Pulse USA):
    • Dryland (11.9 inch of rainfall)
    • Deficit Irrigation (11.9 inch of rainfall + 2.2 inch irrigation)
    • Full Irrigation (11.9 inch of rainfall + 4.4 inch irrigation)
  3. Tillage study at Grant, NE had 2 treatments using field pea variety Durwood (Pulse USA):
    • Tillage (conventional - disk)
    • No-till
  4. Fertility study at Grant, NE had 10 treatments including combinations of seed and in-furrow applied rhizobia inoculants and foliar products (Table 2). Salamanca (Valesco Genetics) field pea variety was used in the study.

Key findings from each study

  • AAC Profit had the highest grain protein content (28.1%) across three sites (Table 1). AAC Profit was also the highest yielding variety among 20 other yellow field pea varieties evaluated.
  • Tillage had no impact on yellow field pea protein or yield (Figure 3).
  • Irrigation had no impact on yellow field pea protein. Deficit irrigation increased field pea yield by 4.5 bu/ac compared to dryland treatment, while no yield increase was observed with full irrigation (Figure 3).
  • Fertility treatments caused no significant change in grain protein content (P-value 0.098). Grain yield ranged from 25 to 48 bu/ac depending on the treatment (Table 2). Rhizobia inoculant product selection and mixing were critical in achieving high nodulation scores and high yields (Table 2). Foliar products had a positive impact on yield when applied at reproductive stages (R1-R4).
Graph of Effect of tillage and irrigation on field pea
Figure 3. Effect of tillage and irrigation on field pea (cv. ‘Durwood’) yield (bu/ac) and grain protein (%) during 2019 growing season at Grant, NE
Table 1 - Grant, NE - Dryland
Variety Company Grant, NE - Dryland
Yield (bu/ha) Protein (%) Protein rank
AAC Profit Valesco Genetics 52.1 28.9 1
LG Amigo Pulse USA 40.6 28.1 2
CDC Spectrum Meridian Seed 41.6 26.9 4
Salamanca Valesco Genetics 42.2 26.4 7
CDC Inca Meridian Seed 53.2 26.6 5
Spider Valesco Genetics 40.5 26.4 8
Durwood Pulse USA 35 26.3 9
CDC Saffron Meridian Seed 48.5 25.2 14
AC Agassiz Meridian Seed 39.1 27.6 3
Jetset Meridian Seed 37.8 25.8 11
CDC Amarilo Meridian Seed 33.1 25.3 13
Polancos Montana Integrity 36.9 26 10
SW Midas Pulse USA 38.6 24.6 20
Bridger Valesco Genetics 39.9 25.2 15
Montech 4152 Arrow Seed 35.4 26.5 6
AC Earlystar Valesco Genetics 43.2 24.7 18
Montech 4195 Arrow Seed 34.2 25.3 12
Nette 2010 Pulse USA 42.9 24.9 17
LG Sunrice Pulse USA 36.1 24.7 19
AAC Carver Meridian Seed 34 25 16
Average of all Varieties 40.8 26.1
P-value
Difference required at 5% level
Table 1 - Grant, NE - Irrigated
Variety Company Grant, NE - Irrigated
Yield (bu/ha) Protein (%) Protein rank
AAC Profit Valesco Genetics 72.5 26.8 1
LG Amigo Pulse USA 69.3 26.4 2
CDC Spectrum Meridian Seed 70.9 26 8
Salamanca Valesco Genetics 65.4 26 9
CDC Inca Meridian Seed 70 25.4 12
Spider Valesco Genetics 68.2 26.1 4
Durwood Pulse USA 71.7 26.4 3
CDC Saffron Meridian Seed 75.4 26 7
AC Agassiz Meridian Seed 64.3 25.4 11
Jetset Meridian Seed 78.5 26.1 6
CDC Amarilo Meridian Seed 68.7 25.3 13
Polancos Montana Integrity 71.1 25.5 10
SW Midas Pulse USA 65.5 26.1 5
Bridger Valesco Genetics 70 25.3 14
Montech 4152 Arrow Seed 68 24.8 15
AC Earlystar Valesco Genetics 65.8 24.4 18
Montech 4195 Arrow Seed 70.3 24.4 17
Nette 2010 Pulse USA 84.2 24.8 16
LG Sunrice Pulse USA 70.5 24.4 19
AAC Carver Meridian Seed 73.5 24.1 20
Average of all Varieties 70.5 25.6
P-value 0.005 <.0001
Difference required at 5% level 8 0.7
Table 1 - Mead, NE - Dryland
Variety Company Mead, NE - Dryland
Yield (bu/ha) Protein (%) Protein rank
AAC Profit Valesco Genetics 80.3 28.5 1
LG Amigo Pulse USA 72.4 26.7 7
CDC Spectrum Meridian Seed 68.5 27.7 3
Salamanca Valesco Genetics 76.4 27.8 2
CDC Inca Meridian Seed 68.5 27.2 4
Spider Valesco Genetics 69.5 26.6 8
Durwood Pulse USA 71.5 25.9 12
CDC Saffron Meridian Seed 71.5 26.9 5
AC Agassiz Meridian Seed 73.4 24.6 16
Jetset Meridian Seed 74.4 25.2 14
CDC Amarilo Meridian Seed 72.4 26.2 9
Polancos Montana Integrity 76.4 25.2 13
SW Midas Pulse USA 75.4 25.9 11
Bridger Valesco Genetics 68.5 26.1 10
Montech 4152 Arrow Seed 65.6 25.1 15
AC Earlystar Valesco Genetics 76.4 26.8 6
Montech 4195 Arrow Seed 76.4 24.3 18
Nette 2010 Pulse USA 76.4 24 20
LG Sunrice Pulse USA 63.6 24.5 17
AAC Carver Meridian Seed 75.4 24.1 19
Average of all Varieties 73 26.2
P-value 0.0024 <.0001
Difference required at 5% level 8 0.8
Table 1 - Average across sites
Variety Company Average across sites
Yield (bu/ha) Yield rank Protein (%) Protein rank
AAC Profit Valesco Genetics 68.3 1 28.1 1
LG Amigo Pulse USA 60.8 10 27.1 2
CDC Spectrum Meridian Seed 60.3 11 26.9 3
Salamanca Valesco Genetics 61.3 8 26.7 4
CDC Inca Meridian Seed 63.9 4 26.4 5
Spider Valesco Genetics 59.4 15 26.4 6
Durwood Pulse USA 59.4 16 26.2 7
CDC Saffron Meridian Seed 65.1 3 26 8
AC Agassiz Meridian Seed 58.9 17 25.9 9
Jetset Meridian Seed 63.6 5 25.7 10
CDC Amarilo Meridian Seed 58.1 18 25.6 11
Polancos Montana Integrity 61.5 7 25.6 12
SW Midas Pulse USA 59.8 13 25.5 13
Bridger Valesco Genetics 59.5 14 25.5 14
Montech 4152 Arrow Seed 56.4 20 25.5 15
AC Earlystar Valesco Genetics 61.8 6 25.3 16
Montech 4195 Arrow Seed 60.3 12 24.7 17
Nette 2010 Pulse USA 67.8 2 24.5 18
LG Sunrice Pulse USA 56.7 19 24.5 19
AAC Carver Meridian Seed 61 9 24.4 20
Average of all Varieties 61.4 26
P-value
Difference required at 5% level

Conclusions

  • There was no evidence that a higher grain yield of yellow field peas causes a reduction in grain protein content (Figure 4).
  • Variety selection is the most important factor influencing grain protein content of yellow field peas; AAC Profit consistently provided high protein content and high yields.
  • Farmers should make every effort to follow the best irrigation, tillage, and fertility practices to increase grain yield and profitability.
A tractor tilling a field
Figure 4. Yellow peas yield (bu/ac) vs grain protein (%) relationship in 2019 yellow field pea experiments.
Table 2
Table 2. Effect of 10 different fertility treatments field pea (cv. ‘Salamanca’) yield (bu/ac), grain protein (%) and nodulation score as affected by different fertility treatments during 2019 growing season at Grant, NE.
Treatments1 Yield rank Yield (bu/ac) Grain protein (%) Plant vigor (1-5)2 Nodule color/ number (1-5) Nodule position (1-3) Nodulation score3
BSG + YEP (seed treatment) fb SG + HM (foliar at R1-R2) 1 47.2 28.2 4.6 4.8 2.8 12.1
Exceed liquid + peat (seed treatment) 2 45.1 27.9 5 5 3 13
BSG (in-furrow) fb SM + YEP (foliar spray at R3-R4) 3 41.9 27.8 5 5 3 13
Exceed peat (seed treatment) 4 40.5 28 4.8 4.6 2.8 12.1
Graph-Ex SA (seed treatment) 5 39.1 28.5 4 3 1.8 8.8
Nitrogen control (pre-plant broadcast 200 kg/ha) 6 39 28.1 5 0 0 5
AGTIV (seed treatment) 7 37.2 28.3 4 2.6 1.8 8.4
BSG (in-furrow) 8 32.1 28.3 2.8 1.3 1 5
BSG (in-furrow) fb BFA + SG + HM (foliar spray at V3) 9 31.3 28.5 3 3.3 2.5 8.8
Untreated control 10 25.7 27.9 1 0 0 0.7
Average of all Varieties 37.8 28.2 4 3 1.9 8.8
P-value 0.0003 0.0988 <.0001 <.0001 <.0001 <.0001
Difference required for significance at 5% 8.5 0.7 3.5 0.8 0.7 1.8

1BSG = BioSync Granular, AGTIV = AGTIV Pulses, YEP = Yield Enhancer Plus. SG = Stoller Grow, HM = Harvest More Urea Mate, BFA = Bio-Forge Advanced, SM = Sugar Mover; 2Scoring scale 1 = poor ratings 5 = excellent ratings; 3Scoring scale (1 to 13) 1 = no nodulation, 13 = excellent nodulation

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