PURSUIT OF SUSTAINABLE HIGH-YIELDING SOYBEANS WITH A FOCUS ON M.O.M. Howard Brown Mgr. Agronomic Information and Environmental Stewardship ILLINI FS

NUTRIENT PLANNING? 17 Essential Nutrients Liebig’s Law of the Minimum (Nutrients) Extrapolated Vision of the Law of the Minimum

LAW OF THE MINIMUM Lost Yield Potential S Mn Zn B N N http://en.wikipedia.org/wiki/File:Minimum-Tonne.svg

STAVES IN THE BARREL Genetics Plant Stand Plant Health Plant Nutrition Row Spacing

SOYBEAN YIELD Yield is dependent on three components total number of pods/ plant number of beans/pod weight of bean (seed size) Yield increases result from increases in total pods/plant The upper limits on beans/pod are genetically limited Pods per plant image: http://www.robbinsfarmgarden.org/category/about/2012-season Beans per pod image: http://www.bountifulgardens.org/Soy-Bean-Envy-Edamame/productinfo/VBE-2420/

SOYBEAN NUTRIENT REQUIREMENTS Fertilizing soybeans not common Visual deficiency symptoms rare (exceptions) Use soil test to determine fertilizer application Plant analysis to help diagnose deficiency Nutrient considerations

NUTRIENTS ESSENTIAL TO PLANT GROWTH Zinc Manganese Iron Copper Boron Chlorine √ Molybdenum √ Nickel √ Carbon Hydrogen Oxygen Free from Atmosphere Nitrogen Phosphorus Potassium Common Fertilizer Programs Calcium Magnesium Sulfur Ca & Mg Adequate Sulfur?

COLLECTIVE USE OF MACRONUTRIENTS Pounds Nutrient / Acre Used NUTRIENT 30 Bushels 50 Bushels 70 Bushels Nitrogen 165 275 385 Phosphorus 16 (37) 27 (62) 37 (85) Potassium 61 (73) 101 (121) 141 (169) Calcium 51 85 119 Magnesium 14 22 31 Sulfur 23 32 ( ) Lbs/A Oxide form on nutrient P x 2.295 = P2O5 K x 1.2046 = K2O

NITROGEN and GROWTH Rhizobia fix approx. 50% of N needed Use inoculum where soybeans not freq. crop N at planting decrease nodulation/dependence? No consistent yield results in research Beneficial specific years/specific locations

NITROGEN N is related to vegetative growth N-fixation begins about 2 weeks following emergence Plant relies on residual N until then N-Fixation decreases rapidly during seed development (R5) Remobilization of N related to maturity color Cloudy days in August impacts grain fill (also N fixation)

ON-FARM DISCOVERY PROJECT: Nitrogen Pre-Plant 30 lbs N Maintenance P2O5 for 90 Bu/A as DAP Post-Emerge (R3-R4) 30 to 50 lbs N at pod set Urea with Agrotain

NUTRIENT MANAGEMENT Follow Agronomy Handbook Guidelines for P and K Optimum P1 and K Test Levels – Yield Maintenance .85 lbs P2O5/Bu 1.3 lbs K2O/Bu Yield 70 Bu. 80 Bu. 90 Bu. 100 Bu. Lbs/A DAP 129 148 166 185 Lbs/A Potash 152 174 195 217

SOIL LOADED WITH CALCIUM/MAGNESIUM

Twenty S Rate Sites in 2007, N. E Twenty S Rate Sites in 2007, N.E. Iowa Soils: 14 loam and silt loam, 6 loamy sand and sandy loam 15 bu/acre 25 bu/acre Source: Dr. John Sawyer, Iowa State University. 2008

No Sulfur 20 lbs. Sulfur

ON-FARM DISCOVERY SULFUR STUDY

EVALUATION Use sulfate-S as the source Gypsum (mined or Sul-4R-Plus) AMS MicroEssentials (MES) ATS 15 – 20 lbs S (as sulfate-S)

OTHER NUTRIENTS Chlorine, Molybdenum, or Nickel Consider: Iron, Manganese, Zinc, Copper, Boron If high pH is an issue – Foliar delivery suggested.

CONSIDERATIONS Soybeans are an annual plant Soybeans abort up to 75% blooms/young pods Stress during fill period most significant on yield

PLANT HEALTH Seed treatment to assure a good start Inoculant if it fits into plan Fungicide to protect leaf area Insecticide to do the same

ON-FARM DISCOVERY Select field that represents most acres Minimize factors identified Compare treatments to traditional practices

NUTRIENT MANAGEMENT PLANNIING Think Liebig’s Law of the Minimum Focus on pods per plant Reduce stress to minimize flower/young pod abortion Optimize growing environment during fill period Work to minimize stress along the way

NUTRIENT PLANNING Use what knowledge research has provided Consider SCN, Inoculation, early growth Don’t be quick to throw away traditional thinking Consider stewardship when using additional inputs Always test before plunging (Utilize the technology) “If it seems too good to be true, it likely isn’t.”

NUTRIENT UTILIZATION STRATEGY It’s about utilization It’s about accountability It’s about Minimizing environmental impact Optimizing yield Maximizing nutrient utilization.

Good things happen when you focus on M.O.M.

“The only way of finding the limits of the possible is by going beyond them into the impossible.”