EVALUATING NITROGEN FERTILIZER SOURCES FOR WINTER WHEAT

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1 EVALUATING NITROGEN FERTILIZER SOURCES FOR WINTER WHEAT Tom Jensen, PhD. Agronomy, CCA, P.Ag. Northern Great Plains Director International Plant Nutrition Institute (IPNI) Saskatoon, SK

2 A not-for-profit, scientific organization dedicated to responsible management of plant nutrients for the benefit of the human family, Member Companies Incitec Pivot 2

3 Commercially Available N Fertilizers Name Chemical Formula Analysis % N-P 2 O 5 -K 2 O Anhydrous Ammonia* NH Ammonium Nitrate** NH 4 NO Ammonium Sulphate* (NH4)2SO S Urea* CO(NH 2 ) Urea Ammonium Nitrate (UAN) solution* NH 4 NO 3 + CO(NH 2 ) 2 + H / * Commonly available ** No longer commercially available

4 Ammonium Nitrate 33 or 34% nitrogen NH 4 NO 3 Dry granular material Hygroscopic (absorbs water) Half of N from ammonium and half from nitrate Was a preferred source of N for surface applications 4

5 Berthelot showed in 1883 that if ammonium nitrate is rapidly heated the following reaction takes place with explosive violence: 2NH 4 NO 3 4H 2 O + 2N 2 + O 2. In combination with gasoline or other liquid hydrocarbons it is a widely used industrial explosive. This explosive mixture combines the advantages of low cost and stability, requiring a high velocity explosive primer to begin detonation.

6 An example of a fertilizer manufacturer press release, In a letter sent to U.S. and Canadian customers this week, Simplot AgriBusiness President Bill Whitacre stated that despite federal, state, provincial, and industry initiatives, the growing climate of concern about ammonium nitrate had resulted in the decision to remove that product from the company s fertilizer line.

7 Fertilizing Winter Wheat A formerly recommended N fertilization practice for winter wheat production was to apply a low rate of, or no N fertilizer at planting, then broadcast the required N as Ammonium Nitrate in early spring (Fowler, 2002). Excess N at planting thought to decrease winter survival Strategy to apply N in the spring to avoid over winter N losses by leaching, or denitrification See if the wheat survived cold winter temperatures before investing in N application

8 Grass Yield Response (t/ac) 1.2 Check Yield t/ac Amm Nit Urea 0.0 Early Fall Late Fall Early Spring Late Spring Time of Application Yield response of bromegrass to 100 lb N/ac as urea and ammonium nitrate at 4 times of application (Westco, ).

9 N Recommendations for Winter Wheat Province or State Recommendation Most Common Practice Alberta Br. Urea early spring Side-band at planting ESN at planting, in-row Broadcast urea in early Spring Manitoba Montana Nitrogen (urea or UAN)can be side-banded or mid-row banded, or applied after seeding in late fall or early spring. Nitrogen (urea or UAN)can be side-banded or mid-row banded, or applied after seeding in late fall or early spring. Broadcast urea in early Spring Broadcast urea in early Spring North Dakota Saskatchewan Broadcast urea, or surface band UAN in early spring, w/wo Agrotain Broadcast urea in early Spring Broadcast urea in early Spring Broadcast urea in early Spring

10 Alternative Nitrogen Fertilizer Strategies for Winter Wheat Regular urea broadcast in the early spring Side-band urea at planting Side-band urea treated with inhibitors or enhancing compounds Controlled release urea in seed-row or sidebanded Broadcast urea treated with inhibitors or enhancing compounds in the fall (Agrotain plus DCD) or spring (Agrotain only) Surface band in spring, w/wo urease inhibitor 10

11 Nitrogen Forms, Timing and Placement 2007, Beiseker, AB Forms of N (5): Urea (U) Ammonium Nitrate (AN) Agrotain Treated Urea (UA) Super Urea (SU) ESN (Controlled Release Urea) Rates (4): 30, 60, 90, 120 kg N ha -1 Placement Timing Combinations (2) : side-banded at planting, or broadcast in the spring, for Urea, AN, UA, SU (3): seed-row, side-banded at planting, or broadcast in the spring for ESN Check Treatment, 0-N

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13 General Results FORM kg ha -1 N Significance SUPER U a 2 UREA a b 3 AGROTAIN a b 4 AN a b 5 ESN (seed-row not included) b RATE a b c d 5 Check TIMING 1 S a 2 F b

14 Urea Placement x Timing kg ha -1 Significance Broadcast in Spring 5570 a 2 Side-banded at Planting b Rate a b c c

15 Agrotain Treated Urea Placement x Timing kg ha -1 Significance Broadcast in Spring 5486 a 2 Side-banded at Planting 4509 b Rate a a b c

16 Super Urea Placement x Timing kg ha -1 Significance Broadcast in Spring 5393 a 2 Side-banded at Planting 4876 a Rate a a ab b

17 Ammonium Nitrate Placement x Timing kg ha -1 Significance Broadcast in Spring 5590 a 2 Side-banded at Planting 3792 b Rate a a a a

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19 ESN Placement x Timing kg ha -1 Significance Seed-row at planting 5459 a 2 Side-banded at Planting 4725 b 3 Broadcast in Spring 4420 b Rate a a a b

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22 Compare 90 kg N ha -1 Treatments Form Rate Placement Yield Ammonium Nitrate 90 Broadcast Spring 6145 a Ammonium Nitrate 90 Band at Planting 3447 b Urea 90 Broadcast Spring 6092 a Urea 90 Band at Planting 4659 b Agrotain 90 Broadcast Spring 6229 a Agrotain 90 Band at Planting 4515 b Super Urea 90 Broadcast Spring 5768 a Super Urea 90 Band at Planting 5738 a ESN 90 Broadcast Spring 4520 c ESN 90 Band at Planting 5280 b ESN 90 Seed-Row Planting 5917 a Check 0 NA LSD at 0.05

23 Compare 90 kg N ha -1 Treatments Form Rate Placement Yield kg ha -1 Statistical Significance Agrotain 90 Broadcast Spring 6229 a Ammonium Nitrate 90 Broadcast Spring 6145 a Urea 90 Broadcast Spring 6092 a b ESN 90 Seed-Row Planting 5917 a b c Super Urea 90 Broadcast Spring 5768 b c Super Urea 90 Band at Planting 5738 c ESN 90 Band at Planting 5280 d Urea 90 Band at Planting 4659 e ESN 90 Broadcast Spring 4520 e Agrotain 90 Band at Planting 4515 e Ammonium Nitrate 90 Band at Planting 3447 f Check 0 NA 2818 g 336 LSD at 0.05

24 One Year, One Site, Preliminary Conclusions Requirement for more research Different N forms are best used at different times and placement combinations (see the next five slides for comments on each nitrogen product.)

25 Ammonium Nitrate Poorly suited for fall side-band application at planting, probably had losses due to denitrification and or leaching Early spring broadcast is best way to use the product

26 Urea Not well suited for fall side-band application at planting, probably had losses due to denitrification and or leaching. Improved compared to ammonium nitrate for side-banding at planting but only marginally. Early spring broadcast is best way to use the product, in this study it performed quite well as an early spring broadcast product but could be susceptible to volatilization losses if inadequate precipitation received within a few days of application.

27 Agrotain Treated Urea Not well suited for fall side-band application at planting, probably had some losses due to denitrification and or leaching. Improved compared to ammonium nitrate for side-banding at planting but only marginally. Early spring broadcast is best way to use the product, in this study it performed quite well as an early spring broadcast product and could be less susceptible to volatilization losses compared to urea if inadequate precipitation received within a few days of application.

28 Super Urea I think this experiment showed that side-banding this product at planting is a good alternative. It was statistically just as high yielding as seed-row placed ESN, and slightly better than side-banded ESN (I m not sure how significant this difference really is, and so more research is needed). So for fall use I think the better alternatives are Super Urea, or ESN. It performed reasonably well as a spring broadcast application, similar to ESN being side-banded at planting, and also similar to spring broadcast urea. It was only slightly lower than spring broadcast ammonium nitrate or Agrotain-treated urea. It would be useful to have a study that compared the following timingplacement combinations for Super Urea: fall broadcast at planting, fall broadcast later in the fall after planting, fall side-banded at planting. It might perform well as a broadcast operation in the fall and could be an attractive alternative to growers who don t want to handle much product at planting of winter wheat.

29 ESN This product looks promising as a seed-row applied product. Growers could use a narrow opener compared to side-banding and save some fuel costs, and reduce soil disturbance. The question is how the economics would compare to sidebanding Super Urea, or broadcasting Super Urea at or after planting of winter wheat.