WSU Wheat Academy

December 12, 2018

Fertility & Residue Mgmt

Outline

Composition of Residue

Nutrient Content

Decomposition

Soil Organic Matter/Carbon

Residue Management

+Nutrients

Temp/Water

erosion protection

Carbon/OM

(soil health)

-Tillage

Harrow/Mow/Flail

Drill interference

Crop performance

temp, immobilization,

herbicide interception

Amount of Straw

1 bushel wheat = 100 lb straw

50 bushel/acre wheat = 5000 lb straw/acre

80 bushel= 8,000 lb/acre

100 bushel = 10,000 lb/acre

http://pnwsteep.wsu.edu/tillagehandbook/chapter3/031690.htm

Composition of Wheat Straw

Straw System Bu Wt N applied

1 DS-SF 85 58.7 110

2 DS-SF 81 58 90

3 Green Pea 90 60 85

4 Green Pea 98 61 85

5 DS-SF 86 59 110

6 DS-SF 94 58 115

7 Green Pea 97 58 80

8 DS-SF 114 60 110

Nutrients in Straw

C, H, O, N, S, P, K, Ca, Mg, Fe, Mn, Cu, B, Zn, Mo,

Cl

Carbon contentStraw % C:N

Ash VS TOC

1 7.2 93 53.8 90

2 7.1 93 53.9 112

3 6.1 94 54.5 133

4 9.1 91 52.7 110

5 7.1 93 53.9 135

6 8.5 91 53.1 100

7 6.0 94 54.5 133

8 6.3 94 54.4 175

Ave 7.2 93 53.9 124

Straw % N % P % K % Mg % Ca % S

1 0.60 0.04 0.84 0.10 0.24 0.07

2 0.48 0.02 0.62 0.07 0.19 0.05

3 0.41 0.02 0.96 0.07 0.17 0.05

4 0.48 0.02 1.25 0.11 0.22 0.08

5 0.40 0.02 1.73 0.07 0.20 0.12

6 0.53 0.03 1.62 0.08 0.26 0.10

7 0.41 0.03 1.11 0.07 0.17 0.04

8 0.31 0.01 1.30 0.05 0.13 0.05

Nutrient content of 8 straws

Ave. 0.47 0.03 1.16 0.08 0.21 0.07

S. D. 0.08 0.01 0.35 0.02 0.04 0.03

Nutrient Content lb/ton 8 Wheat Straws

Straw N P2O5 K2O Mg Ca S

1 12 1.7 20 2 5 1

2 10 1.0 15 1 4 1

3 8 1.0 23 1 3 1

4 10 1.0 30 2 4 2

5 8 0.9 42 1 4 2

6 11 1.3 39 2 5 2

7 8 1.2 27 1 3 1

8 6 0.6 31 1 3 1

Ave. 10 1 28 2 4 1

S.D. 1.37 0.26 9.02 0.31 0.64 0.5

Range 6-12 0.6-1.7 15-42 1-2 3-5 1-2.5

Baled v. direct from combine

Baled v. direct from combine

Straw TDN NDF DMI %

Protein

% N % P % K % Mg % Ca

Swath 49 79.1 13.9 3.9 0.62 0.03 1.4 0.9 0.19

Combine 51 71.3 15.4 4.5 0.76 0.06 1.6 0.1 0.2

Lb/ton

N P2O5 K2O

Swath 12.4 1.3 33

Combine 15.2 2.7 38

Don Horneck OSU Hermiston

• Wheat circle (irrigated)

• Ran the pivot for 5 treatments on straw

• 0, 0.25, 0.5, 0.75 and 1.0 inch of water

applied (Columbia River water)

• Measured P and K in two situations in the

field for all five treatments

– Standing (roughly 8”)

– Laying (what went through the combine)

OSU-HAREC

Why P and K?

• Both soluble

– Not tied to proteins or cell walls like N, S, Ca…

• Both used in moderate to high quantities

– K a high concentration component of straw

OSU-HAREC

0

1

2

3

4

5

6

0 0.2 0.4 0.6 0.8 1 1.2

Irrigation water applied, in

K L

evel,

%

k - laying

k - stand

OSU-HAREC

Potassium

50% +

0

0.05

0.1

0.15

0.2

0.25

0 0.2 0.4 0.6 0.8 1 1.2

water applied, in

P i

n s

traw

, %

p - laying

p - stand

OSU-HAREC

Phosphorous

30%

Summary

• 50% reduction in K in straw that is laying

• 0% in standing

• 30% reduction in P in straw that is laying

• 0% in standing

OSU-HAREC

Nutrient Value of Wheat Straw

Nutrient Price Value

Range

(lb/ton)

Ave.

(lb/ton)

Nutrient

($/lb)

Range

($/ton)

Ave.

($/ton)

N 6-16 11 $0.44 2.60 – 7.00 $4.90

P 2-3 1.5 $0.60 1.20 – 1.80 $1.50

K 20-30 25 $0.30 6.00 – 7.50 $6.30

S 1-3 2 $0.40 0.40-1.20 $0.80

Total 10.25-19.05 $13.50

Winter Wheat Straw

0.55% N, 0.12% P, 0.04% S

Tons

Straw lb N lb P2O5 lb S $

1 11 2.4 0.8 13.50

2 22 4.8 1.6 27.00

3 33 7.2 2.4 40.50

4 44 9.6 3.2 54.00

5 55 12 4 67.50

N @ $0.44 P2O5 @ $0.60, S @ $0.40

GRV Grass Seed Straw Bale Survey - 2007

Lbs Nutrient / ton of Baled Straw

Species N P K

Lbs/ton

KBG (14) 18 – 40 2.6 – 5.4 37 - 54

CRF (7) 11 – 24 1.4 – 3.2 22 - 47

ChF (6) 11 – 23 1.6 – 2.8 22 - 47

HF (3) 19 – 28 2.2 32 - 45

Value of Nutrients in Baled KBG Straw

Price / lb Nutrient Nutrient Value

Average

Per Ton

Oct.

2008

.Dec.

2010Oct. 2008 Dec. 2010

Nitrogen 26 lbs $0.95 0.44 $24.70 $11.44

Phosphorus 3.6 lbs $1.20 0.60 $4.32 $2.16

Potassium 48 lbs $0.60 0.30 $28.80 $20.16

Total $57.82 $33.16

Dry

Weight

lb/acre

Total

N %

Total S

%

Total

P %

Total

K %

N

lb/acr

e

S

lb/acre

P

lb/acre

K

lb/acre

2442 2.59 0.15 0.17 1.62 63 3.7 4.2 40

2332 2.30 0.13 0.18 1.53 54 3.0 4.2 36

2399 2.26 0.14 0.18 1.48 54 3.4 4.3 36

2391 2.38 0.14 0.18 1.54 57 3.4 4.2 37

Pea Green Manure Data (30 June 2008)

What does burning do?

Spring Wheat Straw (Canada) Mean of 4

Nutrient lb/t of straw burned

straw Ash % lost

C 911 85 91%

N 24 0.4 98%

P 3 2.6 18%

K 32 26 24%

S 2.4 0.8 70%

Ca 4.4 3 30%

Mg 2.3 1.7 27%

http://www.farmca.com/news/octdec2001/strawstudy.html

1 Ton Wheat Straw N = 4

Nutrients value lost per acre/ton

removed burned

$11.15 - 16.25 $4.10 - 14.60

http://www.farmca.com/news/octdec2001/strawstudy.html

N $0.29 P $0.27 K $0.14 S $0.24

Tissue Analysis

Soft White Winter Wheat flag leaves at flower 31 May

Tissue Analysis

Soft White Winter Wheat Flag leaves at flower 31 May

Tissue Analysis

Soft White Winter Wheat lower leaves at flower 31

May

Tissue Analysis

Soft White Winter Wheat lower leaves at flower 31

May

Soft White Winter Wheat lower leaves at flower 31 May

Tissue Analysis

Soft White Winter Wheat Flag leaves at flower 31 May

Soft White Winter Wheat lower leaves at flower 31 May

Tissue Analysis

Soft White Winter Wheat Flag leaves at flower 31 May

Soil Decomposition

Water

Soil particles Plant roots

Soil is a habitat

Who’s there?

Macrofauna:

Soil ‘Engineers’

Who’s there?

Mesofauna:

Soil predators,

pathogens,

herbivores

Microorganisms:

Soil process

controllers

1. Decomposition

(shredding residues)

2. Mixing soil (aeration)

Decomposition rate of blue grama (Bouteloua gracilis)

Soil animals are important for

Decomposition

What Factors Control

Decomposition

Position

Sizing

C/N

Distribution

Nutrient content

Temperature

Water

pH

Soil Sci. Sot. Am. J. 44:833-837.N content 0.78, 0.49 and 0.19

Rate of Decomposition

0

20

40

60

80

100

120

Oct-Nov Nov-March March-Nov Nov-March March-Nov

% remaining

Wt.

Time

Above

0.79

0.49

0.19

0

20

40

60

80

100

120

Oct-Nov Nov-MarchMarch-NovNov-MarchMarch-Nov

% remaining

Wt.

0.79

0.49

0.19

Surface

0

20

40

60

80

100

120

Oct-Nov Nov-March March-Nov Nov-March March-Nov

0.79

0.49

0.19

Buried

3.9 tons 0.18 OM

650 lb N 65 lb/year

3600 36003400

4600 4600 4600

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

Fall Plow Spring Plow No-Till

lb/a

cre

Treatment

Wheat-Spring Pea Yield and Residue 1994-2005

Yield Residue

Decomposition

Temperature and Water

Sizing

C/N ration

Added N has small change on the rate of

decomp

Value of residue (straw)

1) Nutrients

2) Insulation (heat and water budget)

3) Carbon & Soil Health (microbial food, carbon credits)

4) Erosion Protection

Insulation Value ($0-42/acre)

Fall Removal 1-2 inches of water storage lost

1 inch of water = 7 bushels wheat/acre

Wheat @ $3.00/bushel

Insulation value of winter straw = $21-42

Spring removal $12

Soil Carbon Value ($2.00/acre)

Carbon Credit $2-5/ton CO2

1 ton C = 2.7 Ton C02 = $7-18/ton carbon

Permanent grass cover at Pendleton

= 300 lb C/year = $1.00-$5.00/year

= C/N 12:1 = 25 lb N @ $0.44/lb = $10

Water infiltration, Water Holding Capacity

Nutrient Holding Capacity

1 inch of water = 7 bushels wheat/acre

Wheat @ $3.00/bushel

`

Fall Removal Spring Removal

-------------$/acre--------------------

Nutrients $15 - 31 Same

Insulation 0-60 0-15

C 2 2

Erosion 0-75 0-35

Other ? ?

Total $15-168 $15-65

Total Value/acre

What other system changes should be

considered when removing Straw

Annual Cropping

Crop rotations

Reduction in fallow

Erosion protection

<5000 straw = insufficient amount

Carbon Change Acre Basis

1 % OM (0-8”) = 24,000 lb OM /acre

OM = about 0.6 OC or 14,000 lb/acre = 7 tons

1% change OM @ 0.15 tons C/acre/year = 46 years

1% change OM top 1” = 6 years

OM C/N 12:1 @ 0.15 ton C = 25 lb N/year

2000 lb N/1% OM

1 ton OM = 100 lb N

Soil Conservation Value ($0-75/acre)

Dollars

• Save per acre if had to buy today by

leaching some of the P and K out

• $103 in K

• $10 in P

• Moral – be careful

OSU-HAREC

Straw % N % P % K % Mg % Ca % S

1 0.6 0.037 0.84 0.1 0.24 0.07

2 0.48 0.023 0.62 0.07 0.19 0.05

3 0.41 0.022 0.96 0.07 0.17 0.05

4 0.48 0.021 1.25 0.11 0.22 0.08

5 0.4 0.019 1.73 0.07 0.2 0.12

6 0.53 0.029 1.62 0.08 0.26 0.1

7 0.41 0.027 1.11 0.07 0.17 0.04

8 0.31 0.014 1.3 0.05 0.13 0.05

9 0.62 0.03 1.36 0.9 0.19

10 0.76 0.06 1.59 0.1 0.2

average 0.5 0.0282 1.238 0.162 0.197 0.07

Straw % N % K % K % Mg % Ca % S

1 0.60 0.04 0.84 0.10 0.24 0.07

2 0.48 0.02 0.62 0.07 0.19 0.05

3 0.41 0.02 0.96 0.07 0.17 0.05

4 0.48 0.02 1.25 0.11 0.22 0.08

5 0.40 0.02 1.73 0.07 0.20 0.12

6 0.53 0.03 1.62 0.08 0.26 0.10

7 0.41 0.03 1.11 0.07 0.17 0.04

8 0.31 0.01 1.30 0.05 0.13 0.05

9*

0.62 0.03 1.36 0.90 0.19

10*

0.76 0.06 1.59 0.10 0.20

Ave. 0.50 0.03 1.24 0.16 0.20 0.07

2% OM Drop in 6 years

acre furrow slice = 2,000,000 lb

2% is 40,000 lb of O.M. /6 years

6667 lb/year.

OM is 60 % C and has C:N ratio 12:1

24,000 lb C and of 2,000 lb N.

Annually 4,000 lb of C and 320 lb N.

https://igrow.org/up/resources/03-2000-2011.pdf

http://www.organicagcentre.ca/DOCs/Extension/Nutrient_Value_Crop_Residu

e_Hollinger.pdf

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex2512/$

http://www.montana.edu/cpa/news/wwwpb-archives/ag/baudr230.html

http://pubstorage.sdstate.edu/agbio_publications/articles/exex8164.pdf

https://ipni.net/ppiweb/bcrops.nsf/$webindex/88BAB5C3A151987285256D

6B004DF5B3/$file/03-3p04.pdf green manutre

Factors to consider when removing straw

Value of straw?

What are the effects in the field and beyond?

positive v. negative.

Will it achieve the desired effect?