25
Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191 [email protected] Mississippi-crops.com

Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center [email protected]

Embed Size (px)

Citation preview

Page 1: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Current Status of Soil Test Calibration in Mississippi

Bobby R. GoldenDelta Research and Extension Center

[email protected]

Mississippi-crops.com

Page 2: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Updating Soil Test Correlations in MS

• Why are we interested in doing this ?

• Changing crop rotational mix

• Improved production practices since last major update

Lancaster unpublished data (19?)

Page 3: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Interpretation of Soil Test Results

• A soil-test value is an INDEX, is not “the” total amount available (snapshot in time)

• Field calibrations with crop response give a meaning to soil-test values by different testing methods.– critical/optimum value or range– interpretation classes– application rate for responsive ranges

Page 4: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

How do we get there ?

• Program Development for Correlation/Calibration

• Currently working on Corn, Soybeans, and Cotton.

• P, K, Zn• Major Goal:

– Field correlate soil test index to yield response and tissue concentrations

Page 5: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Potassium and Corn

• Soil test K in the top 6” of soil is an indicator of corn yield responsiveness in the Midwest.

• Does this hold true for the Midsouth?

• However corn is new to the Midsouth and little research has been conducted to establish critical values

0 lb K2O/acre

160 lb K2O/acre

Page 6: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Corn Response to K Fertilization

Leflore Co

Potash rate (lb K2O/acre)

0 40 80 120 160 200

Me

an

co

rn g

rain

yie

ld (b

u/a

cre

)

100

150

200

250 Bolivar Co.

Potash rate (lb K2O/acre)

0 40 80 120 160 200

Me

an

co

rn g

rain

yie

ld (b

u/a

cre

)

100

150

200

250

Golden unpublished data (2012)

73 bu/ac yield response 27 bu/ac yield response

Page 7: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Corn Response to K Fertilization

Lancaster Soil Test K

Lancaster extractable K (ppm)

0 50 100 150 200 250 300 350

Rela

tive c

orn

yield (%

)

50

60

70

80

90

100

110

Non ResponsiveResponsive

Mehlich-3 Soil Test K

Mehlich-3 extractable K (ppm)

0 50 100 150 200 250 300 350

Rela

tive co

rn yield

(%)

50

60

70

80

90

100

110

Non ResponsiveResponsive

Golden unpublished data (2012)

Page 8: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Potassium and Soybean

• Soil-test K in the top 4 or 6 inches of soil is an excellent predictor of soybean responsiveness to K fertilization.• Slaton et al. 2010• Mallarino et al., 2005• Clover and Mallarino, 2009

Page 9: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Soybean Actual Yield at Responsive sites

Golden unpublished data (2012)

Responsive sites

K fertilizer rate (lbs K2O/acre)

0 40 80 120 160 200

So

yb

ea

n y

ield

(bu

/ac

re)

40

50

60

70

80

90

100Humpherys CoBolivar Co

10 bu/ac response8 bu/ac response

Page 10: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Soybean Yield Response to K Fertilization

Lancaster Soil Test K

Lancaster extractable K (ppm)

50 100 150 200 250 300 350

Rela

tive so

ybea

n yie

ld (%

)

0

20

40

60

80

100

120

Non Responsive SitesResponsive Sites

Mehlich-3 Soil Test K

Mehlich-3 extractable K (ppm)

50 100 150 200 250 300 350

Rela

tive s

oyb

ean

yield

(%)

0

20

40

60

80

100

120

Non ResponsiveResponsive

Golden unpublished data (2012)

Page 11: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Soybean Tissue Response to K Fertilization

Lancaster Extractable K (ppm)

50 100 150 200 250 300 350

So

yb

ea

n T

iss

ue

K @

R2

(%

)

1.5

1.6

1.7

1.8

1.9

2.0

2.1

2.2

2.3

Non Responsive SitesResponsive Sites

Mehlich-3 Extractable K (ppm)

50 100 150 200 250 300 350

So

yb

ea

n T

iss

ue

K @

R2

(%)

1.5

1.6

1.7

1.8

1.9

2.0

2.1

2.2

2.3Non Resonsive SitesResponsive sites

Golden unpublished data (2012)

Page 12: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Mehlich 3 - Lancaster Correlation

Lancaster Extractable K (ppm)

0 100 200 300 400 500

Me

hlic

h-3

Ex

tra

cta

ble

K (

pp

m)

0

100

200

300

400

500

600M3K = 4.102 + 0.9547(lancaster K)

Golden unpublished data (2012)

Page 13: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Mehlich 3 – Lancaster Correlation

M3P = -10.149+0.8140(lancaster)

Lancaster Extractable P (ppm)

0 20 40 60 80 100 120 140 160

Me

hlic

h 3

Ex

tra

cta

ble

P (

pp

m)

-20

0

20

40

60

80

100

120

140

Golden unpublished data (2012)

Page 14: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Zinc Deficiency Symptomology

Page 15: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Methods of Zn Fertilization

• Soil Applied– 10 lb Zn/acre as a

granular fertilizer– Adjust rates based on

water solubility of Zn sources

• Foliar Applied– Apply 1-2 lb Zn/acre after

emergence– Chelated for soil

application (Little foliage for interception)

– Sulfate for foliar application (larger plants)

Page 16: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Zinc Rate Response Trials 2012

Zn application rate (lb Zn/acre)

0 2.5 5 7.5 10

Mean

corn

grain

yield (b

u/acre)

0

50

100

150

200

250

300Bolivar Co (29 bu increase) DREC7 (16 bu increase)

Corn Response to Zn Rate

Page 17: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Lancaster Extractable Zn (ppm)

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

Re

lati

ve

Co

rn G

rain

Yie

ld (

%)

86

88

90

92

94

96

98

100Responsive SitesNon Responsive Sites

Mehlich-3 Extractable Zn (ppm)

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

Re

lati

ve

Co

rn G

rain

Yie

ld (

%)

86

88

90

92

94

96

98

100Responsive SitesNon Responsive Sites

Corn Yield Response to Zn Fertilization

Page 18: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

M3Zn=0.4914 +1.44(lancaster)

Lancaster Extractable Zn (ppm)

0 2 4 6

Me

hlic

h 3

Ex

tra

cta

ble

Zn

(p

pm

)

0

2

4

6

8

10

Mehlich 3 - Lancaster Correlation

Page 19: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Zn Product Foliar Burn

EDTA Chelate @ 2lb ZnCitric Acid Chelate @ 2lb Zn

Page 20: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Zinc Product Foliar Burn @ 6d after application

Zn application rate (lb Zn ac-1)

0.5 1 2

Vis

ua

l Inju

ry Ra

ting

(%)

0

10

20

30

40

50

60

70EDTA ChelatedCitrate Chelated

Page 21: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Zinc Foliar Burn - Tissue Concentration @ 2 WAA

Zn application rate (lbs Zn acre-1)

0.5 1 2Co

rn leaf tiss

ue Z

n c

on

cen

tration

(pp

m)

0

20

40

60

80

100

120

140Main effect of Zn rate (p =<0.0001)

Golden unpublished data (2012)

Page 22: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Zinc Foliar Burn Tissue Concentration @ 2 WAA

Zn Product

Citrate EDTA

Co

rn L

ea

f T

iss

ue

Zn

Co

nce

ntr

ati

on

(p

pm

)

0

20

40

60

80

100

120Main effect of Zn product (p=0.0091)

Golden unpublished data (2012)

Page 23: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Zn Foliar Burn Grain Yield

Zn Rate (lb Zn/acre)

0.5 1 2

Me

an

co

rn g

rain

yie

ld (b

u/a

cre

)

0

50

100

150

200

250

300EDTA ChelateCitric Acid Chelate

Golden unpublished data (2012)

Page 24: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

Zinc Basics

• Soil test Zn coupled with pH is a good indicator of need

• Use the Right rate for the Zn source and soil

• Remember not all Zn fertilizers are created equal– Must take into account water solubility– Supply Zn early

Page 25: Current Status of Soil Test Calibration in Mississippi Bobby R. Golden Delta Research and Extension Center 479-409-6191bgolden@drec.msstate.eduMississippi-crops.com

At the End of the Day

• Fertilizer costs money, but yield pays the bills: High fixed production costs for land, good seed, equipment

– relative costs, and business management approach