· 2017. 1. 19. · nature’s way of adding diversity to a system which lacks diversity. ADEQUATE...

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IMPORTANT FACTORS

• SHORT-TERM STUDIES ARE NOT ACCURATE IN EVALUATING TREATMENTS SUCH AS TILLAGE OR ROTATIONS WHICH HAVE LONG-TERM IMPACTS.

A FARMER MANAGES

ECOSYSTEMS AND TAKES

SUNLIGHT, WATER, AND

CARBON DIOXIDE AND MAKES

THEM INTO PRODUCTS TO BE

SOLD.

ECOSYSTEM PROCESSES

• WATER CYCLE

• ENERGY FLOW

• MINERAL CYCLE

• COMMUNITY DYNAMICS

Wheat Health ManagementCook and Veseth

Crop rotation allows time for natural

enemies to destroy the pathogens of one

crop while……unrelated crops are grown.

SEQUENCE IS

ONLY ONE

COMPONENT OF A

ROTATION

• Proper Intensity

• Adequate Diversity

• Stable/Sustainable Profitability

Crop Rotations

PROPER INTENSITY

Native vegetation is the

best indicator of the range

of intensities which are

appropriate for a location.

PROPER INTENSITY

Most of the plant growth problems

blamed on no-till are the result of

inadequate diversity or improper

intensity.

PROPER INTENSITY

• Put water saved by no-till to work

• More high water-use crops and Cover Crops or Double Crops

• Proper intensity reduces risk

– Plant growth, nutrients, etc.

WEB SOIL SURVEY

ECOSYSTEM PROCESSES

• MINERAL CYCLE-Are the

nutrients available for plant use and

environmental services”? Or have

they been leached, eroded, or

transported from the landscape?

ECOSYSTEM PROCESSES

• MINERAL CYCLE-

–Ecosystems that leak nutrients become

deserts.

–Saline seeps indicate leakage

–Decreasing pH indicates leakage

–One unit train of soybeans contains

almost 1/2 million pounds of phosphorus

Saline Seep Formation

COVER and FORAGE CROPS

Cover and forage crops provide the opportunity to increase both intensity and diversity in situations where production of a grain crop would not be possible, would be unprofitable, or would be excessively risky.

COVER CROPS

In humid environments (tall-grass prairie or wetter) the goal should be to have something growing at all times. In areas with a limited growing season this will require the use of cover crops and/or forage double crops.

COVER CROPS

In subhumid, semiarid, and arid environments cover crops can be utilized to increase organic matter and biological activity and often as a valuable source of forage.

CATCH AND

RELEASE

NUTRIENTS

Irrigated Corn By Previous Crop

Wheat-Wheat-C-C-SB-SB rotation

2009 Dakota Lakes Res. Farm

Rotation N rate 0 lb

Yield

Bu/ac

N rate 36

Yield

Bu/ac

N rate 72

Yield

Bu/ac

N rate 108

Yield

Bu/ac

CC – lentil,

CVetch, turnip

176.0 236.1 214.0 233.9

Nitrogen rate impact on yields

STN = 108 lbs/ac Yield goal = 220 bu/ac

COVER CROPS

If you get stranded in a rain on the back 40, do you drive home across the tilled field or the pasture?

ADEQUATE DIVERSITY

Weeds and diseases are

nature’s way of adding

diversity to a system which

lacks diversity.

ADEQUATE DIVERSITY

Nature’s efforts to add

diversity can be countered

by adding beneficial

diversity to the system.

ADEQUATE DIVERSITY

AT LEAST THREE CROP TYPES.

LONG INTERVALS OF 2 TO 4

YEARS ARE NEEDED TO BREAK

SOME DISEASE AND WEED

CYCLES.

ROTATION IMPACT ON W.WHEAT15 ROTATION STUDY LYMAN COUNTY, SD

1995, 1997, 1998, 1999, and 2000

Interval Between Wheat

Yield

Alternate Year Wheat-XXX

46.8

Two Years Out Wheat-Corn-XXX

53.0

Two In – Two Out SW-WW-Corn-XXX

48.4

Three Years Out WW-Corn-SB-Pea

57.9

Rotation Impact on W.Wheat

Cost/Unit of Production

1994-1995 & 1997-1999

Lyman County

Rotation Cost in $/bu.

WW-Fallow $4.60

WW-Corn-Fallow $3.79

WW-Corn-Pea $2.45

SW-WW-Corn-SB $2.64

Impact of Rotation & Low Disturbance

On Weed Populations

Weed of Interest: Waterhemp

Number of Weeds Previous:10

Number of Seeds Per Weed:100

Rotation Interval Vs. Weeds

-2.0E+06

0.0E+00

2.0E+06

4.0E+06

6.0E+06

8.0E+06

1.0E+07

1 3 5 7 9 11 13 15 17

Years

Weed

s In

Mil

lio

ns

1 Year Out

2 Years Out

2 In - 2 Out

Natural Control Benefit

Cool-Season Weeds (such as Downy Brome)

2 Years of Warm-Season Crops (or Fallow)

Reduce Number of Seeds > 95%

Same with

Warm-Season Weeds Cool-Season Crops

(W-C-F)

Weed Life Cycle Green Foxtail

Ap May June July Aug Sep Oct

Corn P

W. Wheat

Foxtail ------ ( E ) ------ ** ( F ) **

Weed Life Cycle

Ap May June July Aug Sep Oct

Corn P

W. Wheat X X X

Foxtail ------ ( E ) ------ ** ( F ) **

Green Foxtail

Does it Work ? (Field Trial)

Long-Term Rotation Study

Cool and Warm Season Crops

No-Till : Herbicides - Weed Control

Weed Density After 12 Years

(No Herbicides – Number of Weeds / m2)

94

40

7

0

25

50

75

100

W-CP W-C-CP Pea-W-C-SB

Weeds

(plts/m2)

Rotation Design < - > Weeds

Tillage – Seed Survival

Green Foxtail

Seed Placed at 3 Depths in Soil

0, 2, and 4 inches

Measure Number of Live Seed Yearly

Green Foxtail Survival in Soil

After 2 Years

11

28

55

0

20

40

60

0 2 4

Depth in Soil (inches)

Live Seed (%)

Tillage - Weed Seedling Emergence

Weed Seed Shed: (once)

No-Till

Till (seed 1 – 3 inches deep)

Count Seedlings Yearly, for 3 Years

Several Species, Average of 4 Sites

10088

48

32 33 4

0

25

50

75

100

1 2 3

Seedlings Within a Year

Seedlings (%) Till No-Till

Seedling Emergence - Tillage

10088

48

32 33 4

0

25

50

75

100

1 2 3

Seedlings Within a Year

Seedlings (%)

Till No-Till

Corn Pea WW Corn

10088

48

32 33 4

0

25

50

75

100

1 2 3

Seedlings Within a Year

Seedlings (%)

Till No-Till

Corn Pea Corn

DIVERSITY IN CROP TYPE

•Diversity in seeding date.

•Diversity in rooting pattern.

•Diversity in root architecture.

•Diversity in residue type.

•Diversity in insect pests.

DIVERSITY IN CROP TYPE

•Diversity in weed suppression.

•Diversity in micro organisms.

•Diversity in harvest date.

•Diversity in beneficials.

•Diversity in ………MORE.

SIMPLE ROTATIONS

• Winter Wheat-Corn-Fallow

• Winter Wheat-Corn-Canola

• S. Wheat-W. Wheat-Corn-Sunflower

• Winter Wheat-Corn-Pea

• Corn-Soybean

SIMPLE ROTATIONS

Advantages

Simple-limited number of crops to manage

and market.

Disadvantages

Limited-all corn behind wheat or all winter

wheat into spring wheat.

Rotations With Perennial Sequences

• C-SB-C-SB-C-SB-Alf-Alf-Alf-Alf

• Many other examples

Rotations with Perennial Sequences

Advantages

Simple-limited number of annual crops to

manage and market.

Excellent place to spread manure.

Probably can produce more soil structure

than annual crops (grass or grass mixtures)

Biomass crops may hold potential

Rotations with Perennial Sequences

Disadvantages

Difficult to manage sufficient percentage of

land in a perennial crop without grazing.

(harvesting 40% of farm as forage is tough)

(using less perennial minimizes impact)

Marketing perennial crop is an issue.

COMPOUND ROTATIONS

Combination of two or more simple

rotations in sequence to create a longer

more diverse system.

EXAMPLE:

S. Wheat-W. Wheat-Corn-SB-Corn-SB

COMPOUND ROTATIONS

Advantages

Limited number of crops to manage.

Creates more than one sequence for some

crop types.

Disadvantages

Limited ability to spread workload.

COMPLEX ROTATIONS

Rotations where crops within the same crop

type vary.

EXAMPLE:

Barley-W.Wheat-Corn-Sunflower-Millet-

Pea

COMPLEX ROTATIONS

Advantages

Capable of creating a wide array of crop

type x sequence combinations.

Disadvantages

Requires substantial crop management

and marketing skill.

STACKED ROTATIONS

Rotations where crops or crops within the

same crop type are grown twice in

succession followed by a long break.

EXAMPLE:

Wheat-Wheat-Corn-Corn-Soybean-

Soybean

Stacked Rotation Concepts

• The goal is to allow sufficient time for

pest pressure to decline to very low

levels before sequencing the crop or

crop type 2 times.

Stacked Rotation Concepts

• Attempt to keep pest populations diverse (confused). Diversity in sequences and intervals used.

• Mix of long and short residual herbicide programs. Reduces costs and minimizes the chance of resistance and biotype changes.

• Two year break between corn and wheat

STACKED ROTATIONS

Advantages

May be capable of reducing the risk of

developing of biotype resistance.

Can reduce cost of herbicide programs.

Disadvantages

Not well tested.

Some crop sequences may not be ideal.

The goal is to be

INCONSISTENT

in both sequence and

interval

Rotations Utilizing Both Stacked

and Normal Sequences

• Canola-W.Wheat-Soybean-Corn-Corn

• S.Wheat-W.Wheat-Pea-Corn-Millet-

Sunflower.

• WW-WW-WW-WW-Sorg-Sorg-Sorg-

Sorg-SF-SF-SF

Dryland Rotations at DLRF

• W-W-Corn/Sorg-Corn-Broadleaf

• W.Wheat-W.Wheat-Broadleaf-Milo-

Corn-Pea/Canola/Flax

• WW-Corn-Pea

• WW-Soybean-Corn/Milo-Pea

Irrigated Rotations at DLRF

• Continuous Corn (With CC)

• Corn-Soybean (With CC)

• Corn-Corn-Pinto-WW/CC-Soybean/Pinto

• Wheat-Wheat (CC)-Corn-Corn-Pinto/SB

–Soybean/Pinto

The Rotation Must Fit the

Ecosystem and the Operator

• There is no set recipe or “best” rotation

• Individual fields may need differing treatment due to soils, location, proximity, history, landlord, ownership…….

• Understanding the power or rotations is the key.

Corn-Pea-WW

Sb-Corn-Pea-WW

Rotation Impact on W.Wheat

Dakota Lakes Research FarmRotation Yield Precip*

Corn-Pea-WW 2006 60 7.9

SB-Corn-Pea-WW 2006 29

Corn-Pea-WW 2005 92 23.7

Sb-Corn-Pea-WW 2005 57

Corn-Pea-WW 2002 56 6.4

SB-Corn-Pea-WW 2002 28

2013 Yield DataDakota Lakes Research Farm

• C – SB rotation (Cover Crops historically increases soybean yield 7.3 bu/a on average vs no CC in this rotation).

• Yield 2013: Soybean with WW CC 62.9 bu/a. We would have expected around 55.6 bu/a without CC.

2013 Yield DataDakota Lakes Research Farm

• C – C – SB – Wheat - SB rotation

• 1st year SB yield - NO cover crop = 76.3 bu/ac

• 2nd SB yield – Cover Crop = 81.2 bu/ac

2013 Yield DataDakota Lakes Research Farm

• Cover crop increased SB yield (7.3 bu/ac), but more importantly crop diversity increased SB yield by 15.9 bu/ac.

C – SB rotation = 62.9

C – C – SB – Wheat – SB = 78.8 bu/ac

• CONTINUOUS CORN• 203 bu/a

• CORN-SOYBEAN • 217 bu/a

• C-C-SB-W-SB• 235 Corn

DIVERSITY IMPACT

• CONTINUOUS CORN• 1,015,000 corn, 0 soybean, 0 wheat

• CORN-SOYBEAN • 542,500 Corn, 157,250, 0 Wheat

• C-C-SB-W-SB • 470,000 Corn, 157 ,600, 120,000 Wheat

DIVERSITY IMPACT IF 5,000 ACRES

• CONTINUOUS CORN• 1,015,000 corn, 0 soybean, 0 wheat

• CORN-SOYBEAN • 542,500 Corn, 157,250, 0 Wheat

• C-C-SB-W-SB • 470,000 Corn, 157 ,600, 120,000 Wheat

• Would you trade 72,500 bu of corn for 120,000 bu of wheat plus 350 bu of soybean? I would.

DIVERSITY IMPACT IF 5,000 ACRES

ORGANIC MATTER

MAKES A

DIFFERENCE.

“Within all textural groups, as organic

matter increased from 1 to 3%, the

available water capacity approximately

doubled. When organic matter content

increased to 4%, it then accounted for

more than 60% of total AWC“.8

When soil water storage capacity is low,

much of the rain that falls during extended

periods of precipitation is lost. In contrast, a

high water storage capacity, combined with

the effective capture of rain and snowmelt

over the fall, winter and spring can support

a crop through an extended dry period.

Commonality Among Tillage Tools

• All Tillage Tools Destroy Soil Structure.

• All tillage tools decrease water infiltration

• All tillage tools reduce organic matter

• All tillage tools increase weeds.

Tillage is to Agriculture what

Fracking is to Petroleum.

They both increase the speed and

extent of nutrient removal from a

resource-leaving the resource

degraded

Continuous Low-Disturbance No-

till in Combination with Diverse

Rotations and Cover Crops:

A BIOLOGIC ANSWER TO A

BIOLOGICAL PROBLEM

Looking

backward

Looking

forward

Le Caussanel, in the 70’s Le Caussanel, 2011

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beck@dakotalakes.com