Three Key Considerations in Planning Your 2019 Soil Fertility Program Dave mengel Professor Emeritus Soil Fertility and crop production Department of agronomy Kansas State University

Three Key Things to Consider for 2019 Soil Testing: Key for making efficient and effective fertilizer recommendations. Starter fertilizer: Starter placement is a great way to apply low rates of nutrients for corn. Very important at low P, K, S and Zn soil test levels When planting into cold soils: Early, No-till, or in poorly drained soils. Important to apply some N to support early growth when N is knifed in preplant, or when sidedressing with no broadcast N. Care must be taken to avoid stand issues or seedling injury. Apply N efficiently, following the 4-R’s Right Time Right Source Right Placement Right Rate SxTxP all interact with soils and weather to determine the right Rate-

Some Points on Cost Effective Soil Testing Tests to request when soil testing: Surface 6 to 8 inch samples, OM, pH, P, K and Zn Profile 0-24 inch samples, N, S, Cl Soil sampling system to use: In variable or sloping soils, sample by soil type or landscape position In uniform soils, consider grid sampling The goal should be management zones which consider: Soil variability Past management impacts Yield potential and crop removal

Dividing the Field Based on Soils or Topography Topography makes good ‘management zones’ in many areas. In many cases represents soils also Sampling areas should represent a “treatable” area, 5-20 acres in size.

Systematic Grid Sampling Systems Two sampling approaches: Grid point Grid average Normal grid size varies from 1 to 5 acres 200 x 200 = roughly 1 acre 300 x 300 = roughly 2 acres

Starter Fertilizer No-till 2 x2 unit

Planting Time Fertilization Traditional starter fertilizer applications for corn Generally focused on supplying part of the P and K at low ST Starter N can be equally as important: In no-till into wide C:N residues When the main N application is banded as NH3 or UAN How starter N is applied is critical Starter N can cause salt and/or ammonia damage to seedlings In-furrow isn’t an option when adding high rates of N Think 2x2 or surface banding to protect seeds/seedlings Think outside the box for starter placement

Splitting P between Broadcast and Starter Band at Low ST Elliot soil - High Productivity, Low Fertility

Response to Starter Fertilizer Across Tillage Systems Responses > 5 bu Mean Response If one Mean Response Across 11exp Conventional 1/11 12 1.1 No-till 8/11 10 7.9 Mean of 11 studies using 2x2 starter fertilizer and a direct tillage comparison. All done at P ST >20 ppm

More than P may be involved with starter

Effect of Primary N Placement on Starter Fertilizer Response Yield, bu/a No Starter N Starter Broadcast at planting 162 165 Preplant Inject 163 179 Bray P1 ST >40 ppm, No P applied in starter, 20 lb N @UAN

Different Types of Starter Fertilizer Band Applications ‘2 x 2’ Starter ‘2 x 0’ Surface Band or Dribble ‘Pop-up’ or In-Furrow Seed Seed Fertilizer Fertilizer Fertilizer

Starter Effects on Corn Yield (bu/a) 3-year avg, NCK Experiment Field In-furrow 2x2 Side Band 2x0 Dribble No Starter 159 5-15-5 172 194 190 15-15-5 177 197 198 30-15-5 174 216 212 45-15-5 171 215 213 60-15-5 163 214

Plant Population

Take Home Ideas About Starter Great way to apply low rates of fertilizers for N, P, K, S, and micronutrients. Consider using starter when planting early, planting no-till, or in cold wet soils. Use very low rates, less than 6-10 pounds N + K, when placed with the seed to avoid salt or ammonia injury. At low P and K levels soil test levels (<10 ppm P), apply 25% of the recommended rate, as a starter. Apply 20-30 pounds N at planting if balance of N banded preplant or sidedressed.

Nitrogen Fertilization Using the 4-R’s Right Rate Right Source Right Time Right Place

Right N Timing Timing is the traditional tool to address N loss due to Leaching Denitrification Ammonia volatilization Alternatives can include: nitrification inhibitors controlled release products (ESN) Urease inhibitors

V-12 V-6

February urea on surface 159 February ESN on surface 179 Urea V-2 191 Response to Time of Application, Controlled Release Fertilizers and Nitrification Inhibitors in No-till Corn, Treatment Yield, bu/a No N 120 February urea on surface 159 February ESN on surface 179 Urea V-2 191 Urea V-2+ Agrotain 201 Urea/ESN blend 201 Weber and Mengel, 2009

Late Sidedress N Application on Corn Treatment N Rate lb/ac Grain Yield bu/ac Pre-plant N 60 133 e Pre-plant N + 30 at V-8 90 158 d Pre-plant N + 60 at V-8 120 173 c Pre-plant N + 90 at V-8 150 185 bc Pre-plant N + 30 at V-16 166 cd Pre-plant N + 60 at V-16 192 b Pre-plant N + 90 at V-16 206 a Tucker and Mengel, KSU Agronomy North Farm, 2009

Two Recent N Management Studies

2013, 2014 & 2015 Rainfall at Scandia Kansas Time Period Total Rainfall inches Total Rainfall inches 2013 2014 2015 Jan, Feb, Mar 1.85 2.05 2.78 April, May, Jun 10.3 12.62 14.7 July, Aug, Sept 8.98 7.15 5.45 Oct, Nov, Dec 3.85 4.77 3.27 Annual total 24.98 23.74 29.92 Longterm Average 30.60

Effects of Nitrogen application timing on irrigated corn yield, 2013-2015, Scandia, KS Starter At Planting At V-4 At V-10 At R1 Total N 2013 Yield 2014 Yield 2015 Yield 20 161 cd 160 h 152 60 80 167 bcd 192 g 187 120 140 180 ab 211 ef 201 180 200 181 ab 216 de 217 178 ab 202 fg 188 229 abc 216 190 a 230 ab 208 179 ab 195 g 189 202 183 ab 205 184 a 218 bcd 176 abc 223 abcd 213 Rainfall 24.98 23.74 29.92

2013, 2014 & 2015 Rainfall at Rossville Kansas Time Period Total Rainfall inches Total Rainfall inches 2013 2014 2015 Jan, Feb, Mar 4.11 1.79 2.68 April, May, Jun 11.05 11.63 16.59 July, Aug, Sept 11.93 8.69 13.99 Oct, Nov, Dec 4.83 5.51 3.73 Annual total 31.09 27.90 36.31 Long term average 37.09

Effects of Nitrogen application timing on irrigated corn yield, 2013-2015, Rossville, KS Starter At Planting At V-4 At V-10 At R1 Total N 2013 Yield 2014 Yield 2015 Yield 20 197 g 97 e 72 60 80 217 def 165 bcd 118 120 140 235 abc 151 cd 151 180 200 234 abcd 175 abc 154 219 cdef 139 d 123 240 a 168 bc 182 239 ab 187 ab 186 221 cdef 154 cd 117 215 ef 172 abc 147 207 fg 188 ab 159 231abcde 183 ab 167 224 bcdef 193 ab 156 Rainfall 31.09 27.90 36.31

Poorly Drained Soils Prone to Denitrification

“System” Yield 150 UAN on surface 120 150 UAN knifed in 162 Building an efficient system for high residue no-till corn in a poorly drained soil “System” Yield 150 UAN on surface 120 150 UAN knifed in 162 50 surface+100 SD 164 50 PP knifed in + 172 100 SD Knifed in

Take Home on NUE For the maximum NUE & profitability from N timing, try to minimize the potential time between application of N and uptake. Use some early N, like starter if applying primarily sidedress to avoid early N stress. Follow the 4-R’s for N Management Remember, the 4-R’s interact Right Rate Soil Test Right Source/Additive combination N loss mechanism key Right Timing Drainage and soil texture key The key tool for avoiding leaching on sands or denitrification on poorly drained soils such as clay pans. Right Placement Tillage/Residue/N Source (urea or UAN) the key to avoid volatilization.

Questions? dmengel@ksu.edu

Influence of Tillage and Seed-Placed Starter Fertilizer on Corn Growth and Yield Treatment Population Plant Height Grain H2O Yield Tillage Plow 23,900 a 47 a 31.8 b 156 a No-till 22,100 b 44 b 33.7 a 155 a Starter No Pop-up 23,500 a 45 b 33.2 a 153 b Pop-up 22,800 b 48 a 32.4 b 158 a Pre-plant rate 15-25-50 23,000 a 32.8 a 152 b 30-50-100 23,300 a 32.7 a 159 a Pop-up fertilizer rate was 6 gal 10-34-0 per acre

We Don’t Have a Plant Taking Up N Early or Late in the Year Biological activity in the soil begins 60-90 days before corn takes up large amounts of N (V-6). Biological activity in the soil continues 60-90 days after corn stops taking up N in the fall.

Flooding and N efficiency N Source Time of Flooding Weeks after Applying N 2 4 7 -----percent yield ---- NH3 98 100 87 UAN 100 79 72 120 pounds N applied sidedress 4” water applied

CO2 N2 NH3 C Fixation N Fixation Volatilization Cereal Summer crop Legume Cover Crop Fertilizer Crop residue C:N Dynamic Soil Organic Matter Pool Recalcitrant Soil Organic Matter Pool NOx Uptake Decomposition Immobilization Mineralization NH4+ Nitrification Denitrification NO3- Immobilization Mineralization Hi C:N Low C:N Inorganic Pool NH4 & NO3 Leaching

Impact of Soil Test and Starter Fertilizer N on Corn Yield lb N/acre

Right Time

2013, 2014 & 2015 Rainfall at Scandia Kansas Time Period Total Rainfall inches Total Rainfall inches 2013 2014 2015 Jan, Feb, Mar 1.85 2.05 2.78 April, May, Jun 10.3 12.62 14.7 July, Aug, Sept 8.98 7.15 5.45 Oct, Nov, Dec 3.85 4.77 3.27 Annual total 24.98 23.74 29.92 Longterm Average 30.60

2013, 2014 & 2015 Rainfall at Rossville Kansas Time Period Total Rainfall inches Total Rainfall inches 2013 2014 2015 Jan, Feb, Mar 4.11 1.79 2.68 April, May, Jun 11.05 11.63 16.59 July, Aug, Sept 11.93 8.69 13.99 Oct, Nov, Dec 4.83 5.51 3.73* Annual total 31.09 27.90 36.31* Long term average 37.09 *(Dec not posted)

Key Points in Soil Testing

Residual and Applied N versus Grain Yield Asebedo and Mengel, 2014