1

Fallow Replacement in Western Kansas

John Holman

Scott Maxwell & Tom Roberts

Cover Crop Benefits

• Improve soil quality

– Increase soil organic matter

– Reduce soil erosion

– Reduce soil compaction

– Increase water infiltration

• Decrease runoff

– Supply nitrogen

• Suppress weeds

• Government programs (EQUIP & CREP)

• Conserve soil moisture?

• Reduce nitrate leaching?

• Impact yield of following crop?

• Improve soil quality

– Increase soil organic matter

– Reduce soil erosion

– Reduce soil compaction

– Increase water infiltration

• Decrease runoff

– Supply nitrogen

• Suppress weeds

• Government programs (EQUIP & CREP)

• Conserve soil moisture?

• Reduce nitrate leaching?

• Impact yield of following crop?

2

b

a

a

aa a

0.5

0.8

1.1

1.4

1.7

2.0

No Cover Crop Late Maturing Soybean Sunn Hemp

Soil O

rgan

ic C

arb

on

(%

)0 to 3 inch soil depth

3 to 6 inch soil depth

a

ab

b

0

2

4

6

8

0 50 100 150 200

Cu

mu

lati

ve

Wate

r In

filt

rati

on

(in

ch)

Time (min)

Sunn Hemp

Late-Maturing Soybean

No Cover Crop

Increase in Soil C

• Claassen- Hesston, KS

– Wheat/Cover-Sorghum,

2002-2010

– Residue: Sun hemp >

Soybean

• Claassen- Hesston, KS

– Wheat/Cover-Sorghum,

2002-2010

– Residue: Sun hemp >

Soybean

• ↑ Soil C (0-3 in)

• ↑ Water infiltration

• = Soil aggregate stability w/N

• = Soil compaction (0-3 in) w/N

• ↑ Soil ag. and comp. wo/N

• ↑ crop yield @ low N rate only

• ↑ Soil C (0-3 in)

• ↑ Water infiltration

• = Soil aggregate stability w/N

• = Soil compaction (0-3 in) w/N

• ↑ Soil ag. and comp. wo/N

• ↑ crop yield @ low N rate only

Fallow Replacement Study

• Initiated in 2006 at KSU-Garden City

• Crop rotations:

– Wheat-Fallow, Wheat-Wheat, & Wheat-Cover Crop/Forage/Grain,

• RCB design, 4 replications, each phase of the rotation present each year

• Plots are 30’ x 135’, 224 plots total, 11 A study

• Measuring:

– Cover crop water use

– Forage yield and nutritive value

– Water storage in seed zone and profile

– Wheat yield, test weight, and protein

– Profitability/loss of including cover crops in rotation

• Initiated in 2006 at KSU-Garden City

• Crop rotations:

– Wheat-Fallow, Wheat-Wheat, & Wheat-Cover Crop/Forage/Grain,

• RCB design, 4 replications, each phase of the rotation present each year

• Plots are 30’ x 135’, 224 plots total, 11 A study

• Measuring:

– Cover crop water use

– Forage yield and nutritive value

– Water storage in seed zone and profile

– Wheat yield, test weight, and protein

– Profitability/loss of including cover crops in rotation

3

Fallow Treatments (Cover, Forage, Grain)

• Fallow and cont. wheat, 16 treatments total • Fallow and cont. wheat, 16 treatments total

Season Cover Crop

2007 2008 2009 2010 2011

Winter Yellow sweet clover x x

"" Yellow sweet clover/Winter triticale x

"" Hairy vetch x x x x x

"" Hairy vetch/Winter triticale x x x x

"" Winter lentil x x x

"" Winter lentil/Winter triticale x x x

"" Winter pea (grain) x x x

"" Winter pea x x x x x

"" Winter pea/Winter triticale x x x x

"" Winter triticale x x x x x

Spring Spring lentil x x x x x

"" Spring lentil/Spring triticale x x x x

"" Spring pea x x x x x

"" Spring pea (grain) x x

"" Spring pea/Spring triticale x x x x

"" Spring triticale x x x x

Year Produced

Cover and Forage Crop Termination

Winter Peas

• Winter terminated ~May 15 (winter triticale heads)

• Spring terminated ~June 1 (spring triticale heads)

• Plots split: ½ hayed & ½ sprayed out and left standing

• Winter terminated ~May 15 (winter triticale heads)

• Spring terminated ~June 1 (spring triticale heads)

• Plots split: ½ hayed & ½ sprayed out and left standing

4

2008-2010, Crop Biomass

• Winter lentil: 2009-2010• Winter lentil: 2009-2010

531

15071760 1984

2341

370 489 694

4318 4383 4392 4503

0

1000

2000

3000

4000

5000

6000

7000

Len

til

Pea

Len

til/

Tri

tica

le

Tri

tica

le

Pea

/Tri

tica

le

Len

til

Ha

iry

vet

ch

Pea

Len

til/

Tri

tica

le

Tri

tica

le

Ha

iry

vet

ch/T

riti

cale

Pea

/Tri

tica

le

Spring Winter

Fo

rag

e Y

ield

(lb

s/A

DM

)

2008-2010, Crop Biomass Average

• Winter triticale yield > spring triticale

• Legumes: spring yield > winter: winter injury

– Spring pea > winter pea

– Winter lentil = spring lentil

– Hairy vetch 1 year winter kill

• Winter triticale yield > spring triticale

• Legumes: spring yield > winter: winter injury

– Spring pea > winter pea

– Winter lentil = spring lentil

– Hairy vetch 1 year winter kill

1625

2735

2028

4406

1019

518

0

1000

2000

3000

4000

5000

6000

Spring Winter Spring Winter Spring Winter

All Cover Crop Treatments Triticale Treatments only Legume Treatments only

Fora

ge

Yie

ld (

lbs/

A)

100%

Dry

Matt

er

5

Residue or Forage Value?Residue or Forage Value?

Crude Protein (CP)

• Microbial protein and amino acid production

• > 13% “premium” nutritive value

• Alfalfa 18-24% CP

• Microbial protein and amino acid production

• > 13% “premium” nutritive value

• Alfalfa 18-24% CP

Cover Crop CP

15 16 1619 19

2326

1719 19 19

22

0

5

10

15

20

25

30

Pe

a/T

riti

cale

Ha

iry

ve

tch

/Tri

tic

ale

Tri

tic

ale

Le

ntil/T

riti

cale

Le

nti

l

Pea

Ve

tch

Tri

tic

ale

Pe

a/T

riti

cale

Le

ntil/T

riti

cale

Pea

Le

nti

l

Winter Spring

CP

(%

) D

ry M

att

er

6

Total Digestible Nutrients (TDN)

• Energy available

• Alfalfa 61-67% TDN

• Energy available

• Alfalfa 61-67% TDN

Cover Crop TDN

63 63 64 64 64

67

70

6163 63

6667

565860626466687072

Tri

tic

ale

Ha

iry

ve

tch

/Tri

tic

ale

Pe

a/T

riti

ca

le

Ve

tch

Len

til/T

riti

ca

le

Pe

a

Len

til

Tri

tic

ale

Pe

a

Pe

a/T

riti

ca

le

Len

til/T

riti

ca

le

Len

til

Winter Spring

TD

N (

%)

Dry

Ma

tte

r

Cover and Forage Crop

Impact on Winter Wheat

Cover and Forage Crop

Impact on Winter Wheat

7

Wheat Following High Residue, 2007

Following vetchFollowing vetch

Following triticaleFollowing triticale

Wheat Following Low Residue, 2007

Following fallowFollowing fallow

Following lentilFollowing lentil

8

Western KS Moisture Results• Fallow storage, 20-30% effective

• Growing cover crop used moisture

– Improves storage and may improve stand establishment

• Fallow storage, 20-30% effective

• Growing cover crop used moisture

– Improves storage and may improve stand establishment

2008 Yield Results

• Hail week prior to harvest

• Only visual difference was cont. wheat

• Hail week prior to harvest

• Only visual difference was cont. wheat

2008 Winter Wheat Yield following 2007 Cover Crops

13

21 21 22 22 22 23 2426

21 21 21 23 24 22

0

5

10

15

20

25

30

Wh

ea

t

Ye

llo

w s

we

et

clo

ve

r

Tri

tic

ale

Ye

llo

w s

we

et

clo

ve

r/T

ritic

ale

Pea

/Tri

tic

ale

Pe

a (

gra

in)

Hair

y

ve

tch

/Tri

tic

ale

Ve

tch

Pe

a

Pea

/Tri

tic

ale

Tri

tic

ale

Le

nti

l

Pe

a

Le

nti

l/T

ritic

ale

Fallo

w

Winter Spring None

Win

ter

Wh

ea

t Y

ield

(b

u/A

13

.5%

)

9

2009 Winter Wheat Yield following 2008 Cover Crops

57h

74g 76fg 77efg 78efg 81dcef86abc 87abc

79defg83bcde 85abcd

89ab 90a83bcde

0

10

20

30

40

50

60

70

80

90

100

Wh

eat

Clo

ver/

Tri

tica

le

Pea

(g

rain

)

Tri

tica

le

Pea

/Tri

tica

le

Ha

iry

Vetc

h/T

riti

ca

le

Hair

y V

etc

h

Pe

a

Le

nti

l/T

riti

ca

le

Pea

/Tri

tica

le

Tri

tica

le

Len

til

Pe

a

Fa

llo

w

Winter Spring None

Win

ter

Wh

eat

Yie

ld (b

u/A

13.5

%)

2009 Yield Results

• Only visual difference was cont. wheat

• No effect of residue management treatment

• Only visual difference was cont. wheat

• No effect of residue management treatment

2010 Winter Wheat Yield following 2009 Cover Crops

72a 70ab70ab 68abc68bcd 70ab 67bcde67bcde66bcde66bcde 66cde65cde 64de63e

43f

0

10

20

30

40

50

60

70

80

Wh

ea

t

Tri

tic

ale

Pe

a/T

riti

ca

le

Pe

a (

gra

in)

Ha

iry

Ve

tch

/Tri

tic

ale

Le

nti

l/T

riti

ca

le

Pe

a

Le

nti

l

Ha

iry

Ve

tch

Pe

a/T

riti

ca

le

Le

nti

l/T

riti

ca

le

Pe

a

Tri

tic

ale

Le

nti

l

Fa

llo

w

Winter Spring None

Win

ter

Wh

ea

t Y

ield

(b

u/A

13

.5%

)

2010 Yield Results

• Only visual difference was cont. wheat

• Cover yielded 2.9 bu/A more than hay

• Only visual difference was cont. wheat

• Cover yielded 2.9 bu/A more than hay

10

2011 Yield Results

• Very dry year, marginal wheat stands• No effect of residue management treatment• On average spring forage reduced yield 3 bu/A

• Very dry year, marginal wheat stands• No effect of residue management treatment• On average spring forage reduced yield 3 bu/A

2009-2011 Yield Results

• 2 good years, 1 very poor year• No effect of residue management treatment• Winter triticale, grain pea, and cont. ww yields less

• 2 good years, 1 very poor year• No effect of residue management treatment• Winter triticale, grain pea, and cont. ww yields less

11

Field Pea Yields

• Austrian winter pea (2006-2011): too much injury

• Spring pea (2010-2011): 30-35 bu/A

• Feed pea: $4.50/bu (60 lbs/bu)

– 10 bu/A wheat yield reduction

– ~$13/A profit, with 10 bu/A wheat reduction

– Additional $45/A profit compared to chem-fallow

Western KS Preliminary ResultsNone

Vetch Vetch/Trit Lentil Lentil/Trit Pea Pea/Trit Trit Lentil Lentil/Trit Pea Pea/Trit Trit Fallow

Expenses

Drill $/A 11 11 11 11 11 11 11 11 11 11 11 11 0Seed lb/A 25 30 100 63 30 120 76 0Seed $/lb 2.3 0.4 0.3 0.2 0.4 0.2 0.2 0Total seed cost $/A 56 35 12 13 25 20 14 11 14 28 23 17 0Total drilling cost $/A 67 46 23 24 36 30 25 21 25 38 33 28 0

Swath $/A 10 10 10 10 10 10 10 10 10 10 10 10 0Bale & Stack $/ton 16 16 16 16 16 16 16 16 16 16 16 16 0Total hay cost $/A 15 49 14 49 17 50 49 15 26 24 31 28 0

Spray application $/A 5 5 5 5 5 5 5 5 5 5 5 5 5RT3, $/A 3 3 3 3 3 3 3 3 3 3 3 3 32,4-D, $/A 3 3 3 3 3 3 3 3 3 3 3 3 3Applications/A 3 3 3 3 3 3 3 3 3 3 3 3 4Total spray cost $/A 34 34 34 34 34 34 34 34 34 34 34 34 46

Total Expense (cover) 101 80 57 58 70 65 59 55 59 73 67 62 46Total Expense (hay) 116 130 71 107 86 115 109 71 85 96 99 90 46

Returns

Yield ton/A 0.3 2.4 0.2 2.4 0.4 2.5 2.4 0.3 1.0 0.8 1.3 1.1 0.0Price $/ton 91 91 91 91 91 91 91 91 91 91 91 91 0Yield Return $/A 25 221 19 217 35 226 220 27 88 76 118 100 0

N Return lb/A 40 40 40 40 40 40 0 40 40 40 40 0 0N value $/lb N 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5N Return $/A 20 20 20 20 20 20 0 20 20 20 20 0 0

Soil benefits $/ANet Return (cover) -81 -60 -37 -38 -50 -45 -59 -35 -39 -53 -47 -62 -46Net Return (hay) -91 66 -52 85 -52 86 87 -44 -9 -21 7 -3 -46

*Assumption: N contribution from legume 0 when hayed, 50 lbs of N add for winter triticale, and 25 lbs of N add for spring triticale.

Winter Spring

12

COVER CROPS REDUCE SOIL LOSS IN RUNOFF

a

ab

abb

b

0.0

0.5

1.0

1.5

2.0

2.5

Fallow Winter Lentil

Spring Triticale

Spring Pea Winter Triticale

Se

dim

en

t L

os

s (M

g h

a-1

)

COVER CROPS REDUCE THE SOIL’S SUSCEPTIBILITY TO WIND EROSION

a

ab

abc

bc

bc

bc

bc

c

c

c

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Winter Triticale (Hayed)

Fallow (Control)

Winter Lentil (Cover)

Spring Pea (Cover)

Spring Triticale (Hayed)

Winter Triticale (Cover)

Spring Triticale (Cover)

Spring Lentil (Cover)

Spring Pea (Grain)

Continuous Winter Wheat

Wind Erodible Fraction (Aggregates <0.84 mm)

13

Western KS Cool-Season Crops

• Legume

– Clover: biennial-slow growth, seed cost ($25/A)

– Vetch: hard seed, cattle-photosensitization and muscle problems, winter injury, seed cost ($50/A)

– Peas (W & S): winter injury, fair yield, seed cost ($25/A)

– Lentils (W & S): hardy, low yield, seed cost ($11/A)

• Non-legume

– Triticale (W & S): hardy, high yield, seed cost ($15/A)

• Mixtures

– Legumes survive better, high yield, some N fixing, reduce seed cost

• Legume

– Clover: biennial-slow growth, seed cost ($25/A)

– Vetch: hard seed, cattle-photosensitization and muscle problems, winter injury, seed cost ($50/A)

– Peas (W & S): winter injury, fair yield, seed cost ($25/A)

– Lentils (W & S): hardy, low yield, seed cost ($11/A)

• Non-legume

– Triticale (W & S): hardy, high yield, seed cost ($15/A)

• Mixtures

– Legumes survive better, high yield, some N fixing, reduce seed cost

Future Direction

• Wheat-grain sorghum-(fallow/fallow replacement)

• Spring oats compared to triticale

• Radishes and turnips: large taproot-reduce soil compaction?

• Cocktail mixes?

• Wheat-grain sorghum-(fallow/fallow replacement)

• Spring oats compared to triticale

• Radishes and turnips: large taproot-reduce soil compaction?

• Cocktail mixes?

Crop Hay Cover Grain

Spring pea x x x

Spring pea/Spring Oat x x

Spring pea/Spring Triticale x x

Spring Oat x x

Spring Triticale x x

Daikon radish & Shogoin turnip x

Cocktail mix x

(oat, triticale, pea, buckwheat, radish and turnip)

Fallow

14

• Planted 8/30/10

• Harvested 10/14/10

• Size of plants w/ competition

• Planted 8/30/10

• Harvested 10/14/10

• Size of plants w/ competition

• Planted 8/30/10

• Harvested 12/2/10

• Size of plants wo/ competition

• Planted 8/30/10

• Harvested 12/2/10

• Size of plants wo/ competition

Daikon Radish

• Planted 8/30/10

• Harvested 12/2/10

• Planted 8/30/10

• Harvested 12/2/10

• 2/18/11• 2/18/11

Soil depth (in) Soil penetrometer (psi)

1 132

2 244

3 320

4 386

5 468

6 493

7 473

8 493

9 453

10 437

11 442

12 437

15

Mixtures?

• A lot of interest in mixtures

• Some species more competitive

• Select a mixture based on need, more is not necessarily better

– Spring forage: legume improving N content of forage and N fixation, and grass for high biomass (ex: spring pea and oat)

– Spring cover crop: large taproot may help soil quality, legume for N fixation, and large biomass crop (ex: daikon radish, spring pea, and triticale)

– Summer grazing: large taproot for soil quality and grazing, legume, and high biomass (ex: turnip, cowpea, sorghum sudangrass)

• A lot of interest in mixtures

• Some species more competitive

• Select a mixture based on need, more is not necessarily better

– Spring forage: legume improving N content of forage and N fixation, and grass for high biomass (ex: spring pea and oat)

– Spring cover crop: large taproot may help soil quality, legume for N fixation, and large biomass crop (ex: daikon radish, spring pea, and triticale)

– Summer grazing: large taproot for soil quality and grazing, legume, and high biomass (ex: turnip, cowpea, sorghum sudangrass)

Eastern KS: Cover Crop Study

• Cover crop-grain sorghum rotation 3 site yrs (Manhattan & Hutchinson)

• Cover crop biomass

• Cover crop-grain sorghum rotation 3 site yrs (Manhattan & Hutchinson)

• Cover crop biomass

16

Eastern KS: Cover Crop Study

• Grain sorghum yield correlated to N in cover crop

• Correlation to flag leaf N, R2 = 0.79

• Grain sorghum yield correlated to N in cover crop

• Correlation to flag leaf N, R2 = 0.79

Western KS Results

• Impact on wheat yield and profitability?

– In wet years little to no impact on yield

– In drought years all treatments reduced yield except some of the spring crops

– On average spring crops reduced yield (3 bu/A)

– 1 ton forage @ $100/ton: net $40/A more than chem-fallow

vs.

– 3 bu/A @ $8.00/bu: $24.00/A

– Averaged across years:

– Cont. WW reduced yield 37% (25% more total than W-F)

– Winter triticale reduced yield 9% or 5.5 bu/A

– Grain pea reduce yield 11% or 7 bu/A (11 bu/A less in drought)

– No difference between cover or hay

• Impact on wheat yield and profitability?

– In wet years little to no impact on yield

– In drought years all treatments reduced yield except some of the spring crops

– On average spring crops reduced yield (3 bu/A)

– 1 ton forage @ $100/ton: net $40/A more than chem-fallow

vs.

– 3 bu/A @ $8.00/bu: $24.00/A

– Averaged across years:

– Cont. WW reduced yield 37% (25% more total than W-F)

– Winter triticale reduced yield 9% or 5.5 bu/A

– Grain pea reduce yield 11% or 7 bu/A (11 bu/A less in drought)

– No difference between cover or hay

17

Western KS Results

• Bale it, Graze it, or Combine it!

• High seed cost, offsets N contribution- grow own seed

– More economical to apply N

• Select fallow replacement crop adapted to region

– Winter hardiness

– Many proposed cover crops will not perform

• Terminate cover crop prior to June 1 for wheat

• If moisture is available consider double-crop after wheat

• Harvesting crop as forage or grain increased profitability

• Bale it, Graze it, or Combine it!

• High seed cost, offsets N contribution- grow own seed

– More economical to apply N

• Select fallow replacement crop adapted to region

– Winter hardiness

– Many proposed cover crops will not perform

• Terminate cover crop prior to June 1 for wheat

• If moisture is available consider double-crop after wheat

• Harvesting crop as forage or grain increased profitability

Questions?

18

Cover Crops

pea clover vetch

hairy vetch & triticale lentil pea

Planting Spring Crops in the Fall

Spring triticaleSpring triticale Winter triticaleWinter triticale

• Plant a mixture of spring and winter crops for more fall grazing

• Plant a spring crop in the fall for feed in a drought

• Plant a mixture of spring and winter crops for more fall grazing

• Plant a spring crop in the fall for feed in a drought

19

Eastern KS: Cover Crop Study

• Cover crop N accumulation• Cover crop N accumulation

Western KS Warm-Season Crops• Legume

– Oilseed: guar and soybean

– Forage: cowpea, lablab, mungbean, pigeon pea, soybean

– Cover: sunhemp (toxic to cattle)

• Brassicas

– Soil & Cover: turnip, radish, and Ethiopian cabbage

• Grasses

– Forage: forage sorghum, sorghum sudangrass, millet

• Drought, Weeds & Rabbits (2011)

– Best: turnip, radish, guar, cowpea, lablab, Ethiopian cabbage, and grasses