nitrogen fertilization of winter wheat · 2020-03-02 · fertilizing winter wheat •a formerly...

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

•A not-for-profit, scientific organization dedicated to

responsible management of plant nutrients for the benefit

of the human family, www.ipni.net

•Member Companies

2

Incitec Pivot

http://www.ipni.net/

http://www.ipni.net/

http://www.cfindustries.com/

Commercially Available N Fertilizers

Name Chemical Formula Analysis %

N-P2O5-K2O

___________________________________________________________________

Anhydrous Ammonia* NH3 82-0-0

Ammonium Nitrate** NH4NO3 34-0-0

Ammonium Sulphate* (NH4)2SO4 21-0-0-24S

Urea* CO(NH2)2 46-0-0

Urea Ammonium Nitrate

(UAN) solution* NH4NO3 + CO(NH2)2+ H20 28-0-0/ 32-0-0

___________________________________________________________________

* Commonly available

** No longer commercially available

4

Ammonium Nitrate

• 33 or 34% nitrogen

• NH4NO3

• Dry granular material

• Hygroscopic (absorbs water)

• Half of N from ammonium and half from nitrate

• Was a preferred source of N for surface applications

•Berthelot showed in 1883 that if ammonium nitrate is rapidly heated the following reaction takes place with explosive violence: 2NH4NO3 → 4H2O + 2N2 + O2. 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.

An example of a fertilizer

manufacturer press release, 2005.

• 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.

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

1.07

0.81

1.04

0.82

1.13

0.88

1.01

0.86

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Early Fall Late Fall Early Spring Late Spring

Time of Application

Amm Nit

Urea

Grass Yield Response (t/ac)

Check Yield - 0.94 t/ac

Yield response of bromegrass to 100 lb N/ac as urea and

ammonium nitrate at 4 times of application (Westco, 1974-

1988).

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 Nitrogen (urea or UAN)can

be side-banded or mid-row

banded, or applied after

seeding in late fall or early

spring.


Spring

Montana Nitrogen (urea or UAN)can

be side-banded or mid-row

banded, or applied after

seeding in late fall or early

spring.


Spring

North Dakota Broadcast urea, or surface

band UAN in early spring,

w/wo Agrotain


Spring

Saskatchewan


Spring


Spring

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 side-banded

•Broadcast urea treated with inhibitors or enhancing compounds in the fall (Agrotain plus DCD) or spring (Agrotain only)

•Surface band 28-0-0 in spring, w/wo urease inhibitor

10

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

General Results FORM kg ha-1 N Significance 0.05

1 SUPER U 5134 32 a

2 UREA 5070 32 a b

3 AGROTAIN 4998 32 a b

4 AN 4691 32 a b

5 ESN (seed-row not included) 4572 32 b

RATE

1 120 5595 40 a

2 90 5239 40 b

3 60 4550 40 c

4 30 4189 40 d

5 Check 2818.8 4

TIMING

1 S 5285 80 a

2 F 4501 80 b

Urea

Placement x Timing kg ha-1 Significance 0.05

1 Broadcast in Spring 5570 a

2 Side-banded at Planting 4630. b

Rate

1 120 6290 a

2 90 5375 b

3 60 4546 c

4 30 4070 c

Agrotain Treated Urea



2 Side-banded at Planting 4509 b

Rate

1 120 5670 a

2 90 5372 a

3 60 4789 b

4 30 4160 c

Super Urea



2 Side-banded at Planting 4876 a

Rate

1 90 5752 a

2 120 5691 a

3 60 4890 ab

4 30 4203 b

Ammonium Nitrate




Rate

1 120 4999 a

2 90 4795 a

3 30 4664 a

4 60 4307 a

ESN


1 Seed-row at planting 5459 a


3 Broadcast in Spring 4420 b

Rate

1 90 5238 a

2 120 5164 a

3 60 5142 a

4 30 3928 b

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 2818

336 LSD at 0.05

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

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.)

• 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

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.

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.

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 timing-placement 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.

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 side-banding Super Urea, or broadcasting Super Urea at or after planting of winter wheat.

nitrogen fertilization of winter wheat · 2020-03-02 · fertilizing winter wheat •a formerly...

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