Program of Study Committee: Thomas E. Loynachan, Major ... · Evaluating soil characteristics as...

Program of Study Committee:Thomas E. Loynachan, Major Professor

Richard CruseKenneth J. Moore

Iowa State UniversityAmes, Iowa

2016

Raised on family farm located in Green County, Kentucky settled in the 1890’s (fifth generation)

Major crops and forages grown were tobacco, corn, alfalfa, cool season grasses, and legumes

Grew up operating a small dairy and tobacco farm

Still farming today (part-time) beef cattle and forages

Background and History

Education:

Bachelor of Science from Western Kentucky University in Agriculture Business 1987.

Background and History

Work Experience:

USDA, Natural Resources Conservation Service 31 years of service

District Conservationist in Frankfort, Kentucky and currently in Russellville, Kentucky (Logan County)

Developed the Kentucky Soil Erosion and Water Quality Cost Share Program for Kentucky in partnership with the Kentucky Division of Conservation

Currently serving as Natural Resource Planner and Nutrient Management Specialist for Bowling Green Work Unit serving eight counties

Background and History

Background and History

Personal:

Married 17 years (Markita)

One step-son (Matthew) and a granddaughter (Mattie)

Enjoy outdoors, farming, and traveling to National Parks

Background and History

Background and History

Determine causes of large corn yield variations

within similar soil mapping units located in south central Kentucky

Examine soil properties to identify specific soil features correlating to yield reductions

Give consideration to varying corn populations to help overcome a portion of these yield losses

Determine if there are other alternatives or considerations to improving these lower yielding sites

Study Objective

Finding a suitable site…..

Locate site in Mississippian Plateau physiographic region where yield variation is more likely to occur

Similar soil mapping units in project area

Identified wide range of yields within soil mapping units

Multiple years of yield data

Similar field treatments for several years

Cooperating farmer to share data/alter planting

Materials and Methods

Mississippian Plateau consists of a limestone plain

characterized by tens of thousand of sinkholes, sinking streams, streamless valleys, springs, and caverns. This karst terrain occurs because the Mississippian-age limestones are soluble under the right conditions, which means they can easily be eroded by waters moving through the ground

Materials and Methods

PEMBROKE SOIL SERIES

The Pembroke series consists of very deep, well drained soils formed in a thin silty mantle of loess underlain by older alluvium or residuum of limestone or both. They are on nearly level uplands and karst areas. Slopes commonly range from 0 to 2 percent, but the range allows slopes from 0 to 12 percent.

TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Mollic Paleudalfs

Materials and Methods

Materials and Methods

Materials and Methods

Low Yield Potential (L1) Low Yield Potential (L2) Low Yield Potential (L3)

20,000

POPULATION NE

27,500

POPULATION

22,500

POPULATION

25,000

POPULATON

25,000

POPULATION NE

22,500

POPULATON

20,000

POPULATION

27,500

POPULATION

22,500

POPULATION NE

20,000

POPULATION

25,000

POPULATION

27,500

POPULATION

Moderate Yield Potential (M1)

Moderate Yield Potential (M2)

Moderate Yield Potential (M3)

25,000

POPULATION NE

32,500

POPULATION

27,500

POPULATION

30,000

POPULATION

27,500

POPULATION NE

30,000

POPULATION

25,000

POPULATION

32,500

POPULATION

25,000

POPULATION NE

30,000

POPULATION

32,500

POPULATION

27,500

POPULATION

High Yield Potential (H1)

High Yield Potential (H2)

High Yield Potential (H3)

30,000

POPULATION NE

35,000

POPULATION

37,500

POPULATION

32,500

POPULATION

30,000

POPULATION NE

35,000

POPULATION

32,500

POPULATION

37,500

POPULATION

32,500

POPULATION NE

35,000

POPULATION

37,500

POPULATION

30,000

POPULATION

Materials and Methods

Results and Discussion

Results and Discussion

Results and Discussion

Results and Discussion

Results and Discussion

Results and Discussion

Results and Discussion

y = 0.0873x - 4.4994R² = 0.9141***

0

2

4

6

8

10

12

14

16

18

0 50 100 150 200 250

Top

soil

dep

th (

inch

es)

2014 Corn yield (bu/ac)

Relationship of 2014 Corn Yield to Topsoil Depth

Results and Discussion

y = -0.1036x + 45.898R² = 0.7512***

y = -0.0013x + 1.716R² = 0.6792***

1.30

1.40

1.50

1.60

1.70

1.80

0

5

10

15

20

25

30

35

40

45

0 50 100 150 200 250

Bu

lk D

en

sity

(g

/cm

3)

Cla

y C

on

ten

t (

%)

2014 Corn Yield (bu/acre)

Relationship of 2014 Corn Yield to Clay Content &

Bulk Density at 12-inch Depth

▲ Clay

■ Bulk Density

Table 15: Corn yields for 2014 by productivity zone quadrants and different final plant

populations.

Productivity

Zone

Location

Quadrant

Harvested corn

population

(plants/ac)

Corn yield

(bu/ac)

Low 1 NE 16,210 84.2

Low 1 NW 22,000 78.1

Low 1 SE 25,430 85.8

Low 1 SW 24,400 73.0

Low 2 NE 22,000 99.2

Low 2 NW 20,200 89.1

Low 2 SE 22,000 101.2

Low 2 SW 25,430 78.2

Low 3 NE 22,200 71.7

Low 3 NW 22,650 80.7

Low 3 SE 20,315 66.4

Low 3 SW 25,000 74.8

Medium 1 NE 24,400 169.6

Medium 1 NW 23,235 168.8

Medium 1 SE 30,700 144.2

Medium 1 SW 27,900 171.2

Medium 2 NE 26,100 174.4

Medium 2 NW 23,700 165.3

Medium 2 SE 26,731 163.6

Medium 2 SW 32,100 155.5

Medium 3 NE 25,430 163.3

Medium 3 NW 30,344 159.7

Medium 3 SE 30,344 156.4

Medium 3 SW 25,430 169.2

High 1 NE 28,600 204.2

High 1 NW 35,385 212.6

High 1 SE 30,344 205.6

High 1 SW 31,400 204.7

High 2 NE 25,430 184.2

High 2 NW 31,400 176.8

High 2 SE 33,150 188.7

High 2 SW 34,800 175.6

High 3 NE 29,176 206.1

High 3 NW 33,150 206.6

High 3 SE 30,700 189.5

High 3 SW 30,344 193.6

Lower corn yields within the same soil mapping units in

the Mississippian Plateau region of Kentucky are primarily the result of:

Topsoil loss Increase clay content and reduced silt content at the soil

surface Lower organic matter levels below 6 inches in the soil

profile Higher soil bulk density Higher soil calcium and magnesium concentrations Lower soil phosphorus levels

Conclusion

“Almost all people recognize that erosion is harmful, but few realize how harmful. The greatest costs are borne by the landowner and producer” (Frye and Murdock, 1983).

References

References

Dr. Loynachan, Dr. Cruse, Dr. Moore

Dawn Miller

Jerry McIntosh, USDA, NRCS

Dr. Lloyd Murdock, University of Kentucky

Scott Vansickle, Wheat Tech Inc.

Price Farms Inc.

Wesley Wright, Logan County Conservation District

My wife Markita Givens

Acknowledgments

Questions ????