Nitrogen Management Impacts on Wheat Yield and Protein

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1 Nitrogen Management Impacts on Wheat Yield and Protein Steve Orloff, Farm Advisor, UCCE Siskiyou County Steve Wright, Farm Advisor, UCCE Tulare and Kings Counties Mike Ottman, Extension Agronomist, University of Arizona

2 Yield and protein content most important factors determining profitability; N management is key.

3 Discount for not making protein 14 percent standard in PNW 13 percent standard in California markets Discount Premium Year ($/ ¼%) ($/ ¼%) None 2009, 2010, to 10 3 Ave. over yrs Discount varies but an important target

4 Yield Quality Tradeoff

5 Percent of Total Biomass and N Uptake During the Growing Season heading flowering kernel filling maturity can reach 2 3 lbs. per day

6 Percent of Total Biomass and N Uptake During the Growing Season heading flowering kernel filling maturity

7 Percent of total Percent of Total Biomass and N Uptake During the Growing Season heading flowering kernel filling maturity tillering jointing N uptake Biomass 0 Growing Season

8 Yield potential determined by: Density of head-bearing tillers Number of kernels per head Kernel size Density of head-bearing tillers most significant. N at tillering important affects tiller density N during jointing is important because of its influence on the number of kernels per head. N after boot little impact on yield but can affect kernel size

9 How Much N to Apply Growth and N uptake dynamics of the crop Previous crop Yield potential Availability of irrigation water Soil properties Weather conditions Class of wheat high protein is important for hard wheat classes and durum wheat lower protein is desirable for many uses of soft wheat N the soil will supply

10 N Requirement Western US to optimize wheat yields: 3.3 to 5.0 pounds of N (soil + fertilizer) per 100 pounds of grain. Higher yields with acceptable protein use upper end of this range because of decreased N-use efficiency with increasing yield. PNW Maximum yield alone: 2.6 to 3.3 pounds of N per 100 pounds of grain To produce wheat with a protein content of 14 percent: 4.6 to 5.3 pounds N per 100 pounds of grain

11 Pounds of N Needed in the Wheat Plant at Harvest Tons of Grain per Acre Grain Protein (%) Formula from CWC pamphlet protein is 17.5% nitrogen Chart prepared by Gene Askland

12 Expected crop yield minus credits Current available N (NO 3 -N and NH 4 -N) Lbs. NO 3 -N potentially available per acre in each foot of soil multiply parts per million of NO 3 -N by 4 N mineralized from organic matter, manure, and previous legume crops such as alfalfa. 40 to 60 pounds of N per acre credit usually given to alfalfa Irrigation water Multiply the ppm NO 3 -N in the water by and by the number of acre-inches per acre of water to be applied

13 Growth Stages and N Application Timing Effects on Yield and Protein Fertilizer N Addition Increases number of tillers and kernels per head Grain protein comes from remobilized N Affects kernel weight N goes to protein Growth Stage Early Leaf Tillering Stem Elongation (jointing to boot) Heading to Maturation

14 Effect of Late-season N (flowering) on Yield and Protein Kings County Flowering Yield Protein Site N (lbs/acre) (lbs/acre) % Variety: Yecora Rojo K. Cassman, B. Lindquist, S. Wuest, L. Hawe, L. Jackson, & A. Fulton

15 3 Locations San Joaquin Valley (WSREC) Etna (Scott Valley) Tulelake (Klamath Basin)

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17 Nitrogen Fertilizer Regimes 120 lbs N Preplant 50 lbs N Tillering 30 lbs N Boot 30 lbs N Flowering Total lbs N/acre

18 Yield Tons/A Variety Effects on Yield and Protein Levels (averaged over N treatments) 4.5 Scott Valley 4.5 Tulelake Yecora Rojo Hank Fuzion Malbek 2 Yecora Rojo Hank Fuzion Malbek

19 Yield Tons/A Protein (%) Variety Effects on Yield and Protein Levels (averaged over N treatments) Scott Valley Tulelake Yield Protein Yecora Rojo Hank Fuzion Malbek 11 2 Yecora Rojo Hank Fuzion Malbek 11

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21 Yield (Tons/A) N Application Timing Effect on Yield and Protein 4.6 Tulelake, Treatment Preplant Tillering Boot Flowering Yield

22 Yield (Tons/A) Protein N Application Timing Effect on Yield and Protein 4.6 Tulelake, Yield Protein Treatment Preplant Tillering Boot Flowering Yield Protein

23 Effect of N Timing and Rate on Yield and Protein Pedro Andrade, Arizona 2011 Preplant-tillering-flag lb/acre, % protein , , , , , , , , , 11.52

24 Summary N critical for maximum yield and protein Maximum N uptake from stem elongation to heading; biomass lags behind N at tillering important for tiller density; N during jointing important for influence on number of kernels per head Late-season N needed to meet protein requirements Multiply yield goal by N requirement per unit of grain yield to determine N needs N credits (soil nitrate levels), OM or legume, water Varieties differ in N requirement for quality Preliminary results suggest preplant N may not be as important as previously thought May get more benefit from applying more N later in the season

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26 Acres Treated 2010 Herbicide Usage in California-Wheat , , ,940 53,600 67,888 69, ,851

27 Acres Treated 2011/2012 Herbicide Usage in Tulare County-Wheat , , ,903 38, , ,323