Long-Term Application of N, P and K in Continuous Cotton, 1972-2006

Site characteristics

Initiated in spring of 1972 by Dr. Billy Tucker

At the Irrigation Research Station, Altus Clay loam

Variety, dates, seed rate, irr. Frequency

1972-1974

1975-1977 1978-1988 1989-1994 1995-2000 2001-2004

Cultivar

Stoneville 213

LankartLX571

Westburn M

Paymaster 145

Paymaster HS26

Paymaster 2326 BG/RR

Fertilization date

Mid May Apr- May Apr-May Mar-May May Mar- Apr

Planting dates May May May-Jun May May May

Ave seed rate, kg/ha 25 23 22 21 19 18

Ave. frequency of furrow irrigation 2 4 4 3 4 5

Harvest date Dec Nov-Dec Nov-Dec Oct- Mar Oct- Nov Oct-Nov

Treatments

Incomplete factorial combination of N, P and K

N rates 45, 90, 135, 180, 225 kg/ha

P rates 20, 39, 59 kg/ha K 75 kg/ha

check plot

highest N rate

At maturity

Lint yield by variety, Altus, OKlahoma

200

400

600

800

1000

1200

1400

Sto

nevi

lle21

3 (7

2-74

)

Lank

art

LX-5

71(7

5-77

)

Wes

tbur

nM

(78-

88)

Pay

mas

ter

145

(89-

94)

Pay

mas

ter

HS

26 (9

5-00

)

PM

232

6B

G/R

R(0

1-04

)

Lint

yei

ld k

g ha

-1

Response to continuous application of N by variety cotton experiment, Altus, Oklahoma.

0200400600800

1000120014001600

Stone Ville213 (72-

74)

LankartLX-571(75-77)

WestburnM (78-88)

Paymaster145 (89-

94)

PaymasterHS26 (95-

00)

PM2326BG/RR(01-04)

N-P-K, kg/ha

Lint

yie

ld k

g/h

a

0-0-0 0-20-7545-20-75 90-20-75135-20-75 180-20-75225-20-75

SED=63

SED=66 SED=60

SED=46SED=47

SED=73

Response to P application by variety, cotton experiment, Altus, Oklahoma.

0

500

1000

1500

2000

Stone Ville213 (72-

74)

WestburnM (78-88)

PaymasterHS26 (95-

00)

N-P-K

Lin

t yi

eld

, kg

/ha

0-0-0 135-0-75135-20-75 135-39-75135-59-75

SED=51

SED=70

SED=66

SED=48SED=49SED=59

Response to K application by variety, cotton experiment, Altus, Oklahoma.

0

200

400

600

800

1000

1200

1400

1600

Stone Ville213 (72-74)

Lankart LX-571 (75-77)

Westburn M(78-88)

Paymaster145 (89-94)

PaymasterHS26 (95-

00)

PM2326BG/RR (01-

04)

Lin

t yi

eld

, kg

/ha

0-0-0135-20-0135-20-75