Nitrogen and phosphorus recalibration for modern varieties of sunflower (Helianthus annuus, L.) in the northern Great Plains of the U.S.A. Eric Schultz1, Dave Franzen1, Chris Graham2, and Lakesh Sharma1 1Department of Soil Science, North Dakota State University, Fargo, North Dakota 2South Dakota State University, Brookings, South Dakota Abstract Results All Sites, Treatment N Rate vs Yield >56 kg ha-1 Residual N Sites vs Yield All Sites, Total Known Available N vs Percent Oil Sunflower producers in the northern Great Plains are presently directed 4500 46 4000 y = -0.0096x2 + 3.3698x + 1669.9 y = -8E-06x2 - 0.0027x + 39.583 to N and P recommendations that originate from research performed in 2 R² = 0.0309 R² = 0.0369 1
1 4000 y = -0.0034x + 2.0273x + 1648.4 - - 3500 44 the late 1960s and 1970s. In 2014, one year out of a two-year study to R² = 0.0083
3000 3500 42 kg ha kg recalibrate the N and P recommendations for modern varieties of ha kg 3000 2500 40 sunflower was completed with 11 dryland sunflower field sites in North 2500 2000 38 Dakota and three dryland sunflower field sites in South Dakota. Each 2000 1500 36 field study site included N fertilizer rates of 0, 45, 90, 134, 179, and 224 1500 percent Oil,
kilograms per hectare and P fertilizer rates of 0, 34, 67, and 101 1000 1000 34 Sunflower Yield, Yield, Sunflower kilograms per hectare. Yield and oil measurements were analyzed using Yield, Sunflower 500 500 32 least significant difference (LSD) and quadratic polynomial correlation 0 0 30 with N rates. Yield responses to N and P were observed at nine and two 0 50 100 150 200 250 0 100 200 300 400 500 0 50 100 150 200 250 300 350 N treatment rate, kg ha-1 N treatment rate, kg ha-1 Total known available N, kg ha-1 sites, respectively, out of 14 total sites. Sunflower oil content responded -1 All Sites, Total known available N vs Yield <56 kg ha Residual N Sites vs Yield -1 to N and P- at four and three sites, respectively, with the 101 kilogram 4000 2 3500 >56 kg ha Residual N Sites vs Percent Oil y = -0.007x + 3.784x + 1460 46
R² = 0.0407 y = 1E-05x2 - 0.0097x + 39.679
1 1
per hectare rate yielding the greatest percent increase in oil, and the 45 - - 3500 3000 44 R² = 0.0179 kilogram per hectare N rate providing the greatest percent increase in oil 3000
2500 42
kg ha kg kg ha kg over the check. 2500 2000 40 2000 Introduction Yield, 38 1500 • Northern Great Plains states of North Dakota, South Dakota, and 1500 36 1000 percent Oil,
Minnesota produce more than 80% of total sunflowers in the United States 1000 34 Sunflower Sunflower on a yearly basis (USDA-NASS, 2015). Yield, Sunflower 500 500 y = -0.0124x2 + 5.5771x + 1343 32 • Since development of first N and P recommendations, production practices 0 0 R² = 0.112 30 of crop rotations and conservation tillage, as well as technologies of crop 0 100 200 300 400 500 0 50 100 150 200 250 300 0 100 200 300 400 protection products and genetics-based solutions through defensive Total known available N, kg ha-1 Total known available N, kg ha-1 Total known available N, kg ha-1 Mature sunflowers breeding (Hulke and Kleingartner, 2014) have advanced. Table 1. Selected 2014 site information including pre-plant soil test values for NO3-N and P. <56 kg ha-1 Residual N Sites vs Percent Oil • Current yield-based recommendation formulas reflect linear responses to Site ID Texture Tillage-Previous Crop NO3-N NO3-N Olsen-P Soil-P 46 -1 fertilizer (Franzen, 2010): (kg N ha ) Rank (ppm 15 cm) Category* 44 A-ND Silt loam No-till-wheat 43 Low 5 L N-rate = (0.05 x Yield Potential (or Yield Goal)) – N credits 42 B-ND Silt loam No-till-wheat 33 Low 14 H P-rate = (0.0225 – (0.0014 x STP)) x YP (or YG) 40 • Updated recommendations for corn (Franzen, 2014) and wheat (Franzen, BF-ND Loamy sand No-till-wheat 38 Low 17 VH C-ND Silt loam Conventional till-corn 205 High 21 VH 38 2009) in North Dakota have successfully utilized curvilinear yield response DN-ND Silty clay loam No-till-corn 149 High 32 VH 36
to fertilizer. Sunflower updated recommendations will include curvilinear percent Oil, DS-ND Silty clay No-till-corn 32 Low 8 M 34 yield response as well. HT-ND Loam No-till-corn 85 High 19 VH 32 2 HZ-ND Loam No-till-wheat 92 High 18 VH y = -4E-05x + 0.0086x + 39.256 R² = 0.0145 Objectives H-ND Fine sandy loam No-till-wheat 115 High 9 M 30 1. Develop modern N recommendations for sunflower grown in the northern NU-SD Silt loam No-till-wheat 81 High 16 VH 0 50 100 150 200 250 300 Total known available N, kg ha-1 Great Plains using general productivity history, documented responses, O-SD Silt loam No-till-wheat 96 High 10 M and economic analysis. P-SD Silt loam No-till-wheat 61 High 17 VH VC-ND Loam No-till-wheat 33 Low 14 H Summary 2. Develop modern P recommendations for sunflower grown in the northern W-ND Loam Conventional till-corn 68 High 12 H • Poor yield-N relationships reflect specific production issues including lodging, bird Great Plains using general productivity history, documented responses, *Soil-P categories with percent chance of response with addition of fertilizer P: L: Low, 50-80%; M: Medium, 20- damage, and downy mildew. and economic analysis. 50%; H: High, 10-20%; VH: Very High, <10%. • High residual N impacted yield and oil responses the greatest, limiting N influence from Materials and Methods References: 2 Visual treatment difference in green color of sunflower -Franzen, D.W. 2009. Fertilizing hard red spring treatments resulting in observed R values. • The study was conducted over 14 total sites in two states, with 11 sites in wheat and durum. NDSU Extension Circular • Response to P for yield and oil occurred on one site with low soil-P and three others with North Dakota and three sites in South Dakota. 224 kg N Rate 45 kg N Rate 712 (Revised). North Dakota State University high/very high soil-P. Overall, P appears micronutrient-like given the lack of response from Extension Service, Fargo, ND. • Soil was sampled for residual nitrate-N to 61-cm depth; P sampled to 15- -Franzen, D.W. 2010. North Dakota fertilizer first-year results. cm depth. recommendation tables and equations. NDSU • Shape of the yield and oil response curves, particularly for the high residual N sites, • The experimental design was a RCBD with four replications per site. Extension Circular SF-882 (Revised). North suggest that deep residual N (below 60 cm) is providing substantial N for sunflower. • The treatments were arranged in a split-plot with 6 N rates (0, 45, 90, 134, Dakota State University Extension Service, Fargo, ND. • Experiments located on sites with lower residual N indicate that modern varieties of 179, and 224 kg N per hectare) applied preplant as ammonium nitrate in -Franzen, D.W. 2014. Soil fertility sunflower require more N per kilogram of yield than formulas for the northern Great the main plots and 4 P rates (0, 34, 67, and 101 kg P per hectare) applied recommendations for corn. NDSU Extension Plains currently recommend. preplant as triple superphosphate in the sub-plots. Circular SF-722 (Revised). North Dakota State • Second year results, 2015, will provide a more extensive dataset needed to adequately • Experimental unit size: 3 x 9.1 m. University Extension Service, Fargo, ND. -Hulke, B.S. and L.W. Kleingartner. 2014. formulate new recommendations. • Sites planted, with cooperators’ hybrid choice, and managed by cooperator Sunflower. In Yield Gains in Major U.S. Field (herbicide application(s), no additional fertilizer added). Crops. CSSA Special Publication 33. ASA, CSSA, Acknowledgements • South Dakota sites were planted and managed by the South Dakota State and SSSA, Madison, WI. We would like to thank the National Sunflower Association for their support of this team. -USDA-NASS, 2015. USDA crop production summary. ISSN: 1057-7823, January 19, 2014. project. • Seed yield and percent oil were obtained.