nitrogen dynamics in cabbage Jan 25 - Cornell University · 2018. 3. 14. · Nitrogen Use in Summer...

Exploring Nitrogen Dynamics in Cabbage

Christy Hoepting1Cornell Cooperative Extension Vegetable Program

Cornell Cooperative ExtensionVegetable Program

2017 Empire State Producers Expo: Cabbage SessionSyracuse, NY: January 17, 2017

• Funding provided by:• NY Cabbage Research & Development Program

• Grower Cooperators:• Steve Starowtiz, S.J. Starowitz Farms, North Byron, NY (trial)• Dean & Joe Brightly, Brightly & Sons, Hamlin, NY (trial)• Eric Hansen, Hansen Farms, Stanley, NY• Mike Riner and Emma Long, CY Farms, Elba, NY• John Voelpel, Voelpel Farms, Newfane, NY• Colby Homestead Farms, Spencerport, NY• Torrey Farms, Elba, NY• Star Grower, Elba, NY

Acknowledgements

• Technical Advisor:• Steve Reiners, NYSAES

• CVP Program Assistants: • Elizabeth Buck (2014‐2015)• Cordelia Hall (2014)• Missy Call (2015)• Amy Celentano (2016)• Mariam Taleb (2016)

• Fertilizer provided by:• Growmark FS, Knowlesville• CY Farms

• Nitrogen stabilizer provided by: • John Boston, Dow AgroSciences

Acknowledgements

Mariam, Amy & Christy

Nitrogen Dynamics in Cabbage

• CRDP made cabbage fertility with an emphasis on nitrogen as one of their highest research priorities in 2014

• Concerned that too much nitrogen left in fields following harvest of summer cabbage may be causing lodging of following winter wheat crop

Lodging of winter wheat

Nitrogen:• Cornell recommends 100 to 120 lb/A• 40 lb broadcast and incorporated prior to planting• 40 lb in the band at planting• 20 to 40 lb side‐dressed 4 weeks after planting

• A lot of variability in rate & timing of N application

Cornell Recommendations

Nitrogen Use in Summer Cabbage in New York

Rate (lb/A) and Timing of Nitrogen Application Ratio

Total Pre‐ & At‐Planting

Side‐Dress #1 (4 wks)

Side‐dress #2 (6 wks)

PlantingSide‐dress

#1 #2

72.5 72.5 100 0105 105 100 0150 150 100 0210 210 100 0129 89.7 39.1 69 31152 98.4 53.3 65 35157 75 82 48 52185 80 75 30 43 41 16150 60 45 45 40 30 30141 21 120 15 85185 42.7 142 23 77

• Total lb/A: Range; 72.5 to 210 lb/A; Average: 149 lb/A• Ratios of planting to side‐dress range from 100:0 to 15:85

All at planting

Two‐thirds at planting

50:50 split

More at side‐dress

• To study nitrogen dynamics in summer cabbage with respect to:

• total rate applied• timing of application (proportion applied pre‐plant compared to side‐dressed)

• Use of nitrogen stabilizers

• To refine use of nitrogen in cabbage: • To improve efficiency• Optimize rates• To reduce environmental contamination and/or problems with lodging in following winter wheat crop

Objectives

Nitrogen Use in Cabbage

Smith et al. 2016

cabbage

90 days18 days

30 days(side‐dressing)

54days(early cupping)

Head formation

Maximum nitrogen use(Last 3rd of

growing season)

• 5 rates of total applied nitrogen:• 31 lb/A• 66 lb/A• 132 lb/A• 197 lb/A• 262 lb/A

• 3 application timings – ratio at plant: side‐dress• 100%: 0%• 50%: 50%• 25%: 75%

• Included no applied nitrogen (= 2.2 lb from MAP)

2014 On‐Farm Small‐Plot Trial

• 4 Fields (5 acre sections divided into 4 replicates)• 3 summer cabbage (c.v. Transam)• 1 storage cabbage, red (c.v. Kilmaro)

• Soil nutrients: Available NO3‐N• Pre‐fertilizer• Pre‐side‐dress• Early cupping• Heading• Harvest)

• Tissue Analysis: %N• Early Cupping• Harvest (head & leaves)

2015 Case Studies

• Yield: Head & residue• Fresh weight• % dry weight

• Estimate Nitrogen Uptake

2014 Grower Survey• 9 fields summer cabbage• Soil sample at harvest

• Available NO3‐N

2016 On‐farm Small‐Plot Trial

• 3 rates of total applied nitrogen:• 100 lb/A• 150 lb/A• 200 lb/A

• 2 application timings – ratio at plant: side‐dress• 100%: 0%• 50%: 50%

• Nitrogen Stabilizer (a.i. nitrapyrin)• None• At planting (surface spray followed by incorporation with fry fertilizer)

• Side‐dress (applied with 30‐0‐0, knifed in as a liquid)

2016 On‐farm Small‐Plot TrialNitrapyrin• Instinct II (Dow AgroSciences) @ 37 fl oz/A• Nitrification inhibitor• Bactericide of nitrosomonas bacteria (convert ammonium (NH4

+) into nitrite (NO2‐)

Nitrogen Cycle

NO2‐

Nitrite

NO3‐

NitrateAvailable!

NH4+

AmmoniumAvailable!

PLANT FOOD PLANT FOOD

N2Nitrogen Gas

LOST!

Amide N(unavailable)

NH3Hydrogen Gas

LOST!

NO3‐

NitrateLOST!

Small‐Plot Trial, 5 reps

cv. Constellation (storage cabbage), planted Jun‐10Plot size: 7.5 ft x 19 ft; 3 rows – harvested inside heads of inside row

Side‐dress Nitrogen

Nitrogen source: 30‐0‐0 liquidApplied by hand on Jul‐10, 5 weeks post‐transplanting

The most important factor affecting yield was…Rate of applied nitrogen!

Results

Effect of Total Applied Nitrogen on Yield (Ton/A) ‐2014 Trial

27.5

31.833.2

37.038.8

y = 0.0459x + 27.346R² = 0.9447

0

5

10

15

20

25

30

35

40

45

0 50 100 150 200 250 300

Mean Estim

ated

Yield (Ton

/A)

Total Nitrogen Applied (lb/A)

Application timings pooled across applied nitrogen rate

31 lb 66 lb 132 lb 197 lb 262 lb

c

a

abcab

bc

cv. Constellation

Hoepting & Reiners, 2014

P=0.0004

2014: Storage cabbage; normal yearFor each additional 50 lb/A of applied Nitrogen,Yield increases 2.3 ton/A150 lb/A N = 34 ton/A

Clubroot Assessment

Each plant rated for clubroot and weighed individually

2014 Trial ‐ Effect of Total AppliedNitrogen on Club Root (Severity Rating)

0.7

1.0

1.3 1.3

1.5

y = 0.0031x + 0.7327R² = 0.8739

0.0

1.0

2.0

3.0

0 50 100 150 200 250 300

Mean Club

Roo

t Severity

(scale: 0

‐3)

Rate of Applied Nitrogen (lb/A)

Application rates pooled across applied nitrogen timings

cv. Constellation


3.0 = severe

2.0 = moderate

0.0 = none

1.0 = minor

As rate of applied nitrogen increased, severity of club root increased

31 lb 66 lb 132 lb 197 lb 262 lbP=0.0000

c

aab ab

b

Clubroot Severity: Scale 0‐3None = 0 Minor = 1 Moderate = 2 Severe = 3

No club rootAll healthy roots

Club root starting, mostly healthy

roots

A lot of club rootSome functioning

roots

Virtually no functioning roots


27.5

31.833.2

37.038.8

y = 0.0459x + 27.346R² = 0.9447

0

5

10

15

20

25

30

35

40

45

0 50 100 150 200 250 300

Mean Estim

ated

Yield (Ton

/A)

Total Nitrogen Applied (lb/A)

Application timings pooled across applied nitrogen rate

31 lb 66 lb 132 lb 197 lb 262 lb

c

a

abcab

bc

cv. Constellation


P=0.0004

Would yield be even higher in absence of Clubroot?Would nitrogen use be more efficient in absence of clubroot?

32.9 33.5 34.1

0

5

10

15

20

25

30

35

40

0 50 100 150 200 250

Estim

ated

Yield (ton

/A)

Total Amount of Applied Nitrogen (lb/A)

Application Timings Pooled Across Total Rate of Nitrogen Applied

34.7 ton

32.3 ton

2016: Summer cabbage; very hot & dry yearFor each additional 50 lb/A of applied Nitrogen,Yield increases 0.6 ton/A150 lb/A N = 33.5 ton/A

cv. Bronco


Hoepting 2016

irrigated

100 lb 150 lb 200 lb

• According to these results, we did not yet hit the ceiling with respect to the response of applied nitrogen on yield

• > 262 lb/A in 2014 with club root• > 200 lb/A in a hot dry year• In a Canadian study, maximum yield reached at 566 lb/A N

• Significant interaction occurred between applied N rate and application timing for:

• Head size (lb) = ton/A• This means that head size responds differently to total N rate applied depending on the application timing

2014 Results: Effect of Total Applied Nitrogen

5.6 5.8

4.9

5.6

6.9

0

1

2

3

4

5

6

7

8

9

10

0 50 100 150 200 250 300

Cabb

age he

ad weight (lb)

Rate of Total Applied Nitrogen (lb/A)

100:00:00

2014 Trial: Effect of Nitrogen Timing on Head Weight (lb)

Ratio of Total Rate AppliedAt planting: side‐dress

31 lbP: 31S: 0

66 lbP: 66S: 0

132 lbP: 132S: 0

197 lbP: 197S: 0

262 lbP: 262S: 0

cv. Constellation


P=0.0239

b ab

a

bb

No significant difference between 31 lb & 197 lb

100% of total Nitrogen applied at plantingMax

yield at 262 lb/A

4.4

5.96.3 6.9

6.3

0

1

2

3

4

5

6

7

8

9

10

0 50 100 150 200 250 300

Cabb

age he

ad weight (lb)


50:50:00



31 lbP: 15.5S: 15.5

66 lbP: 33S: 33

132 lbP: 66S: 66

197 lbP: 99S: 99

262 lbP: 131S: 131

cv. Constellation


b

aba

P=0.0011

aa

50% of total Nitrogen applied at planting; 50% side‐dress

Max yield at 66 ‐ 262 lb/A

4.0

4.9

6.2

7.36.9

0

1

2

3

4

5

6

7

8

9

10

0 50 100 150 200 250 300

Cabb

age he

ad weight (lb)


25:75b

b

aa

a



31 lbP: 8.2S: 23

66 lbP: 16S: 49

132 lbP: 33S: 99

197 lbP: 49S: 148

262 lbP: 66S: 196

Maximum response to applied N@ 132 lb

P=0.0001

cv. Constellation



4.0

4.9

6.2

7.36.9

4.4

5.96.3 6.9

6.3

5.6 5.8

4.9

5.6

6.9

0

1

2

3

4

5

6

7

8

9

10

0 50 100 150 200 250 300

Cabb

age he

ad weight (lb)


25:7550:50:00100:00:00



31 lb 66 lb 132 lb 197 lb 262 lb

cv. Constellation



100% of total Nitrogen applied at planting

31 lb 66 lb 132 lb

197 lb 262 lb

cv. Constellation



31 lb 66 lb 132 lb

197 lb 262 lb cv. Constellation



31 lb 66 lb 132 lb

197 lb 262 lbcv. Constellation

33.4

34.7 34.6

32.4 32.3

33.6

20

22

24

26

28

30

32

34

36

38

50 100 150 200 250

Estim

ated

Yield (ton

/A)

Total Rate of Applied Nitrogen (lb/A)

50:50

100:0

100

150

200

100: 0 50: 50

2016 Trial: Effect of Nitrogen Timing on Yield (Ton/A)

Timing

Split N app increased yield by

4.6%

1

5

9

3

7

11

33.4

34.7 34.6

32.4 32.3

33.6

20

22

24

26

28

30

32

34

36

38

50 100 150 200 250

Estim

ated

Yield (ton

/A)


50:50

100:0

2016 Trial: Effect of Nitrogen Timing on Yield (Ton/A)

Timing


4.6%

• Applying nitrogen in split applications resulted in more efficient use of nitrogen than 100% at planting

• Opportunity to reduce total nitrogen rates

cv. Bronco

Hoepting 2016


Smith et al. 2016

Time of side dressing35 out of 92 days = 0.38Only 0.11 of total N has

been taken up0.11

33.4

34.7 34.6

32.4 32.3

33.6

20

22

24

26

28

30

32

34

36

38

50 100 150 200 250

Estim

ated

Yield (ton

/A)


50:50

100:0

2016 Trial: Effect of Nitrogen Stabilizer onYield

35

35.635.6

31.7

33.833.7

34.1

33.5

36.3

30.8 31.131

20

22

24

26

28

30

32

34

36

38

50 100 150 200 250

50:50 none 50:50 Stabilizer 100:0 none 100:0 stabilizer

Timing Timing & Nitrogen Stabilizer


4.6%

Stabilizer reduced yield by

8.5%

(Side‐dress)

(At planting)

cv. Bronco

Hoepting 2016

35 35.6 35.6

31.7

33.8 33.734.1 33.5

36.3

30.8 31.1 31

0

5

10

15

20

25

30

35

40

100 150 200

Yield (ton

/A)

Rate of Total Nitrogen Applied

Estimated Total Yield (ton/A): 92 DAP (Aug‐30 & Sep‐9)


cd

aab

dbcd

a‐dabc

d

50 lb

N

50 lb

N

100 lbN

100 lbN

100 lbN

100 lbN

75 lb

N

75 lb

N

150 lbN

200 lbN

200 lbN

150 lbN

a‐da‐d a‐d a‐d

50 lb

N

50 lb

N

100 lbN

100 lbN

75 lb

N

75 lb

N

2016 Trial ‐ Yield (ton/A): Aug‐30 to Sep‐9 (~92 DAP)

#1

Hoepting 2016cv. Bronco

Not significantly different than highest yielding treatment

35 35.6 35.6

31.7

33.8 33.734.1 33.5

36.3

30.8 31.1 31

0

5

10

15

20

25

30

35

40

100 150 200

Yield (ton

/A)




cd

aab

dbcd

a‐dabc

d

50 lb

N

50 lb

N

100 lbN

100 lbN

100 lbN

100 lbN

75 lb

N

75 lb

N

150 lbN

200 lbN

200 lbN

150 lbN


50 lb

N

50 lb

N

100 lbN

100 lbN

75 lb

N

75 lb

N

2016 Trial ‐ Yield (ton/A): Aug‐30 to Sep‐9 (~92 DAP)


These results suggest tremendous opportunity to reduce nitrogen inputs in summer cabbage

production, especially in a dry year

35 35.6 35.6

31.7

33.8 33.734.1 33.5

36.3

30.8 31.1 31

0

5

10

15

20

25

30

35

40

100 150 200

Yield (ton

/A)




cd

aab

dbcd

a‐dabc

d

50 lb

N

50 lb

N

100 lbN

100 lbN

100 lbN

100 lbN

75 lb

N

75 lb

N

150 lbN

200 lbN

200 lbN

150 lbN


50 lb

N

50 lb

N

100 lbN

100 lbN

75 lb

N

75 lb

N

2016 Trial – Effect of Nitrogen Stabilizer on Yield (ton/A)


‐14.6%‐5.3%

‐7.2%‐5%

‐9.4% ‐9.6%

Paired comparison is significantly different

78.2

126

115

0

20

40

60

80

100

120

140

0 50 100 150 200 250

Total A

vailable Nitrogen

in Soil (NO3‐N + NH4

‐N) (lb/A)


PSD 50:50 none PSD 50:50 StabilizerPSD 100:0 nonePSD 100:0 stabilizer Cupping50:50 noneCupping 50:50 Stabilizer

No correlation:‐ Pre‐side‐dress NO3‐N ‐ Amount N applied

‐ Cupping NO3‐N‐ Yield

Strong correlation:‐ Head weight‐ Pre‐side‐dress NO3‐N(Pearson: R = 0.7515; p = 0.0196)

Pre‐Side‐Dress35 DAT (Jul‐12)NO3‐N = 82%

Early Cupping61/67 DAT (Aug‐3 & 9)NO3‐N = 43%

Total Available N (NO3‐N + NH4‐N):Pre‐Side‐Dress & Early Cupping

50:50 none50:50 N stabilizer (side‐dress)100:0 none100:0 N stabilizer (at planting)

Rate x Timing x N Stabilizer


Total Available N (NO3‐N + NH4‐N):Pre‐Side‐Dress (35 DAT: Jul‐12)

70.4

80.5

108

53.4

86.9

108

78.2

126

115

64.6

115110

0

20

40

60

80

100

120

140

100 150 200

Total A

vailable N (N

O3‐N + NH4

‐N) in Soil (lb

/A)

Rate of Total Applied Nitrogen

Total Available Nitrogen (NO3‐N + NH4‐N) at Pre‐Side‐Dress (Jul‐12: 35 DAP)


cd

d

ab

a

d

bcd bcdbcd

abcabcab

ab

50 lb

N

50 lb

N

100 lbN

100 lbN

100 lbN

100 lbN

75 lb

N

75 lb

N

150 lbN

200 lbN

200 lbN

150 lbN

Same rate of applied N

Total Available N (NO3‐N + NH4‐N):Pre‐Side‐Dress (35 DAT: Jul‐12)

70.4

80.5

108

53.4

86.9

108

78.2

126

115

64.6

115110

0

20

40

60

80

100

120

140

100 150 200

Total A

vailable N (N

O3‐N + NH4

‐N) in Soil (lb

/A)

Rate of Total Applied Nitrogen

Total Available Nitrogen (NO3‐N + NH4‐N) at Pre‐Side‐Dress (Jul‐12: 35 DAP)


cd

d

ab

a

d

bcd bcdbcd

abcabcab

ab

50 lb

N

50 lb

N

100 lbN

100 lbN

100 lbN

100 lbN

75 lb

N

75 lb

N

150 lbN

200 lbN

200 lbN

150 lbN


Nitrogen stabilizer at planting reduced available N at pre‐side‐dress by average 10%

‐8.7%‐4.3%

‐17.4%

Total Available N (NO3‐N + NH4‐N):Early Cupping (61 DAP: Aug‐3 & 9)

8.4

24.6

31.432.3

16.5

29.7

12.5

39.1

65.6

12.2

23.7

15.1

0

10

20

30

40

50

60

70

100 150 200

Total A

vailable Nitrogen


‐) (lb

/A)


Total Available Nitrogen in Soil (NO3‐N + NH4‐N) at Early Cupping (Aug‐3 & 9: 61 DAP)


cd

a

bcd

bcd

bcd

bcd

bcd

cd

bc

cd

bcd

bcd

‐39.4% ‐77%

+38%

At Side‐dress At planting

In 3 out of 6 side‐by‐side comparisons, N stabilizer had reduced available N by an average of 50%

‐32.9%



8.4

24.6

31.432.3

16.5

29.7

12.5

39.1

65.6

12.2

23.7

15.1

0

10

20

30

40

50

60

70

100 150 200

Total A

vailable Nitrogen


‐) (lb

/A)




cd

a

bcd

bcd

bcd

bcd

bcd

cd

bc

cd

bcd

bcd

‐39.4% ‐77%

+38%


N stabilizer applied at plating (100:0) reduced NO3‐N more than when it was applied at side‐dress (50:0)

‐32.9%



8.4

24.6

31.432.3

16.5

29.7

12.5

39.1

65.6

12.2

23.7

15.1

0

10

20

30

40

50

60

70

100 150 200

Total A

vailable Nitrogen


‐) (lb

/A)




cd

a

bcd

bcd

bcd

bcd

bcd

cd

bc

cd

bcd

bcd

‐39.4% ‐77%

+38%


As rate of applied N increased, suppression of NO3‐N availability increased

‐32.9%


Total Available N (NO3‐N + NH4‐N):Harvest (92/100 DAP: Aug‐30 & Sep‐9)

17.4

11.4

8.4

20.3

25.1

5.6

10.4

12.7

18.7

15.9

5.6

8.8

0

5

10

15

20

25

30

100 150 200

Available Total N

itrogen


‐N) (lb/A)


Available Total Nitrogen in Soil (NO3‐N + NH4‐N): 92/100 DAP (Aug‐30 & Sep‐9)


‐56%

‐56%

‐33%

2.2x

+53%

+17%

23% NO3‐N:Trial average: 8 lb/A

(0‐32 lb/A)


Lb/A Average Minimum Maximum2014 Nitrogen Trial(33‐262 lb/A N)Storage cabbage

7.5 1.8 29.0

2014 Grower SurveySummer Cabbage 9.0 2.1 43.3

2015 4‐Field Case Study3 Summer; 1 storage cabbage 8.0 0.0 30

2016 Nitrogen Stabilizer Trial (50‐200 lb/A N)Summer cabbage

8.0 0 32

Salinas Valley, CA study(30 broccoli, cabbage & cauliflower fields)

10 (NO3‐N + NH4‐N)

‐‐ ‐‐

Canada study(0‐446 lb/A N)c.v. Bartolo

8‐10(0‐267 lb/A N)

26.7(267‐446 lb/A)

Available NO3‐N Left in Soil at Harvest

Available NO3‐N Left in Soil at Harvest

< 10 lb/A NO3‐N is low:• Low risk for leaching and environmental contamination

• Causing winter wheat to lodge• Cabbage has a high capacity to scavenge nutrients

• Highest correlation in 2016 study was between:• Head weight • Nitrogen Uptake

Nitrogen Uptake in Cabbage:Head & Leaf Residue (2016)

168

185

221

175

223218

178.2

211

226

180.4

199

211

0

50

100

150

200

250

100 150 200

Amou

nt of N

itrogen

used by crop (head + leaves) (lb/A)

Rate Of Total Applied Nitrogen (lb/A)

Nitrogen Use: Amount of Nitrogen (lb/A) Used by Cabbage

50:50 none 50:50 Stabilizer 100:0 none 100:0 stabilizer Linear ( 50:50 Stabilizer)

dd

bc

a

d cd

ababab

cd

aa


Nitrogen Uptake in Cabbage

Lb/A Nitrogen Head(Harvested)

Stump & Leaves

(Left in Field)

Total N Use

2015 4‐Field Case Study2 Summer; 1 storage cabbage

101(=48%) 109 210

2016 Nitrogen Stabilizer Trial (100‐200 lb/A N)Summer cabbage

96.5(=48%)(56‐143)

103(78‐143)

200(168‐226)

Cabbage Leaves Behind ~100 lb of Nitrogen in Crop Residue

• Amount of nitrogen left behind in cabbage field in leaf and stump residue is ~ 100 lb/A

• 80 to 120 lb/A of nitrogen for winter wheat. • Once crop takes up 150 lb/A it is prone to lodging.• Results suggest that the nitrogen left behind in cabbage leaf & stump residue will mineralize and certainly may be a contributing factor to lodging of winter wheat

• Or, may leach into ground water• Plan on reducing rate of applied nitrogen when winter wheat (or other crop) follows summer cabbage

• On‐farm experimentation (e.g. strip trials) • How to capture 100 lb/A N following storage cabbage?

Nitrogen Uptake in Cabbage:Head & Leaf Residue

168

185

221

175

223218

178.2

211

226

180.4

199

211

0

50

100

150

200

250

100 150 200

Amou

nt of N

itrogen

used by crop (head + leaves) (lb/A)

Rate Of Total Applied Nitrogen (lb/A)

Nitrogen Use: Amount of Nitrogen (lb/A) Used by Cabbage


dd

bc

a

d cd

ababab

cd

aa

100 lb/A

150 lb/A

200 lb/A


Uptake exceeds applied by11‐26 lb/A



Where Else Does Cabbage Get Nitrogen From?

• Organic matter• 10‐20 lb/A per 1% OM• 20 lb/A for healthy soils; 10 lb/A for poor quality• 2016 Study had 2.9% OM = 58 lb/A• At most 150 and 200 lb/A of total applied nitrogen

treatments, this would close the gap• Breakdown of residue from previous crop

• E.g. corn stubble• Previous nitrogen‐fixing legume crop• Can rate of nitrogen be predicted?

• Soil test to measure OM• Nitrogen credits from manure and legumes• PSNT test to determine nitrogen?


Smith et al. 2016

0.11

Time of side dressing35 out of 92 days = 0.38Only 0.11 of total N has

been taken up

Can Nitrogen Application Be Predicted?

Total Cabbage Uptake ~214 lb/AMinus nitrogen in soil (58 lb/A) 156 lb/AMinus nitrogen already taken up by crop (23 lb/A) 133 lb/AExample: 100 lb/A N applied at planting:

Minus PSNT test (64.6 lb/A)Add 68 lb/A(169 total)

Example: 100 lb/A N applied at planting:Minus PSNT test (108 lb/A)

Add 25 lb/A(126 total)

Example: 50 lb/A N applied at planting:Minus PSNT test (70.4 lb/A)


Example: 75 lb/A N applied at planting:Minus PSNT test (80.5 lb/A)


Calculations based on 2016 trial results

Using %OM and pre‐side dress test to predict amount of nitrogen to apply at side‐dress with varying rates of N applied at planting resulted in 114 to 169 lb/A of total nitrogen used.

PSNT Soil Test for Fall Cabbage:Northeast U.S.

Heckman et al. 20022 weeks POST‐transplanting:

If PSNT: < 9 ppm (= 18 lb/A)Apply 90‐160 lb/A N=100% standard rates

If PSNT: 10 ‐ 16 ppm (= 20‐ 32 lb/A)Apply 40‐120 lb/A N

(standard rates reduced by 25‐50%)

If PSNT: ≥ 24 ppm (= 48 lb/A)No response to applied N

Summary

• Most important factor driving cabbage yield is amount of applied nitrogen

• When 100% nitrogen applied at planting, highest rates gave highest yields and climbing

• 2014 trial: 262 lb/A• 2016 trial: 200 lb/A

• Rate of increase in yield per 50 lb/A N:• Normal year (2014): 2.3 ton/A• Dry year (2016): 0.6 ton/A

Summary

Split applications of nitrogen between planting resulted in more efficient nitrogen use• Maximum yields achieved at:

• 2014 50:50 ‐ 197 lb/A N• 2014 25:75 – 132 lb/A N• 2016 50:50 – 150 lb/A N

• Nitrogen stabilizer (nitripyran) significantly decreased yield by 8.5% in a hot dry year

• Reduced availability of soil nitrogen• Demonstrating that it worked!

• Especially when applied at planting as a surface spray and then incorporated; compared to no stabilizer:

• 4 – 17% reduced NO3‐N + NH4‐N at side‐dress• 39‐77% reduced NO3‐N + NH4‐N at early cupping

• How would it perform in a normal or wet year?

Summary

• Cabbage is a very effective scavenger of nitrogen from soil

• Typically uptake exceeds amount applied• <10 lb/A of available nitrogen remains in the ground at harvest

• ~ 100 lb/A of nitrogen is left in the field in crop residue after harvest

• Experiment with reduced rates of nitrogen in crops following harvest of summer cabbage (such as winter wheat)

• Expect a healthy cabbage crop to use ~215 lb/A of nitrogen

Recommendations

• 150 lb/A total applied nitrogen• Cornell guidelines are too low

• Split applications:• Maximum 50% at planting• 50 – 75 lb/A pre‐plant & at planting• 75 – 100 lb/A at side‐dressing

• Adjust rate according to PSNT, %OM and field history

• Consider a nitrogen stabilizer at planting in a wet spring?

Questions?

Date post:	22-Aug-2020
Category:	Documents
Upload:	others
View:	0 times
Download:	0 times

nitrogen dynamics in cabbage Jan 25 - Cornell University · 2018. 3. 14. · Nitrogen Use in Summer...

Documents