Comprehensive information on Nitrogen Use Efficiency for cereal crop productionExperiment 222: Long-Term Application of N, P, and K in Continuous Winter Wheat, est. 1968

GPS
Coordinates:
36.122056, -97.091259   (Experiment 222)

Aerial Image, 222, 2/5/2016 Experiment 222, Nitrogen Use Efficiency
Aerial image, 2/5/2016

E222_14.xlsx (Long Term Data Base)
E222_15.xlsx (9/14/2015)

Video, Experiment 222, May 15, 2017
Pictures below taken March 31, 2016

Experiment 222, Stillwater, OK, Long-term-Experiment

Experiment 222, Stillwater, OK, Long-term-Experiment
Experiment 222, February, 2017, and March, 2017
Experiment 222, Stillwater, OK, February 2017 Experiment 222, Agronomy Experiment Station
Experiment #222, Stillwater, OK   222 1990's 222, 2004  PLOT PLAN (ppt file)

Aerial view experiment 222
Experiment 222 Experiment 222 Experiment 222
Avg. Std Dev
Days, >100 F 52 2011 74.44 21.92
  27 2012 75.72 17.80
Days, >90 F 106 2011 74.44 21.92
  88 2012 75.72 17.80

222 high temps 2011

222, 2012 High Temps

2013 Experiment 222 High Temps

 
Experiment 222, plot plans

Abstract

In 1968, experiment #222 was initiated at the Agronomy Research Station in Stillwater, Oklahoma.  This trial was established to evaluate long-term winter wheat grain yield response to applied nitrogen (N), phosphorus (P) and potassium (K).  Applications of sulfur (S) and magnesium (Mg) (Sul-Po-Mag) were also compared.  In the first decade of the experiment, few responses to applied N, P and/or K were found.  Following twenty years without fertilization, average check plot yields were 20 bu/ac.  It was not until the third decade of this experiment that a dramatic response to applied N was observed.  A tendency for increased yields with applied P and K (5 vs 6 and 8 vs 9) was present for the 1989-98 time period, but, this was not significant.  Over the 31 years that these treatments have been evaluated, only applied N has produced a significant increase in grain yields.  In many regards this continuous wheat data demonstrates the difficulty of evaluating P and K fertilizers since no response could be induced without fertilization following 31 years.  Nitrogen applied at an annual rate of 80 pounds per acre was adequate to produce near maximum yields in all three decades evaluated. Considering these results it can also be concluded that if there was no response to applied K (as KCl), there would also be no response to applied Cl.  Also, no response was seen to applied S and/or Mg as K,MgSO4.  Grain %N increased with increasing rates of applied N in all three decades evaluated.

Materials and Methods

Experiment #222 was established in 1969 under conventional tillage on a Kirkland silt loam (fine, mixed, thermic Udertic Paleustoll).  Wheat was planted for 22 continuous years in 10-inch rows at seeding rates of 60 pounds per acre.  Since 1992, winter wheat has been planted in 7.5-inch rows.  The variety 'Scout 66' was planted from 1968-73, 'Triumph 64' from 1974-1977, 'Osage' from 1978-80 and 'TAM W-101' from 1981-91, 'Karl' from 1992-1994, 'Tonkawa' from 1995 to 1998 and ‘Custer’ since 1999.  Changes in management, fertilization and application dates are reported in Table 1.  The experimental design employed was a randomized complete block with four replications.  Fertilizer treatments used in this experiment and average grain yield means over selected periods are reported in Table 2.  Surface soil (0-6 inches) test analyses from samples collected in 1995 are also reported in Table 2.  Individual plots at this site are 20 feet wide and 60 ft long.  The center 10 feet (1969-1995) and 6 ft (1996-present) of each plot was harvested with a conventional combine the entire 60 ft in length for yield.  In addition to wheat grain yield measured every year from this experiment, periodic soil and grain samples were taken for further chemical analyses.

A significant response to applied N was not seen until the second decade of the experiment (Table 2, 1979-1988).  Since that time, applied N has resulted in significant yield increases.  Other than applied N, limited response to applied P or K has been found in this experiment.  However, a recent trend for increased yields as a result of applying K has been observed, especially at the high rates of applied N.  Considering these results it can also be concluded that if there was no consistent response to applied K (as KCl), there would also be no response to applied Cl.  Also, no response was seen to applied S and/or Mg as K,MgSO4 (treatment 13 versus 3). 

The fertilizer treatments evaluated have resulted in relatively small surface soil pH (0-6 inches) changes following 27 years (1969-1995) of continuous winter wheat.  Soil test P declined with increasing applied N, a result of increased depletion.  Surface soil organic matter levels have not changed dramatically, however, organic matter levels have increased at the high N rates when compared to the 0 N checks.   

References

Ranney, R.W. 1969. An organic carbon-organic matter conversion equation for Pennsylvania surface soils. Soil Sci. Soc. Amer. Proc. 33:809-811.

Table 1.  Treatment  applications, and experimental management for continuous winter wheat Experiment 222, Stillwater, OK, 1969-2015.

Year Variety Fert App Planting Harvest Date Seeding Rate Topdress
    Date Date     Date
1969 Scout 66       60  
1970 Scout 66       60  
1971 Scout 66       60  
1972 Scout 66       60  
1973 Scout 66 10/3/1972 10/9/1972   60 3/16/1973
1974 Triumph 64       60  
1975 Triumph 63 8/29/1975     60  
1976 Triumph 64       60  
1977 Triumph 64     6/15/1977 60  
1978 Osage   9/9/1977 6/14/1978 60 3/29/1978
1979 Osage     6/29/1979 60  
1980 Osage     6/25/1980 60  
1981 TAM W-101     6-31-81 72  
1982 TAM W-101 9/18/1981 9/22/1981 6/14/1982 60  
1983 TAM W-101 9/29/1982   6/21/1983 90 3/1/1983
1984 TAM W-101 8/31/1983 10/5/1983 6/25/1984 72  
1985 TAM W-101 8/23/1984 10/2/1984 6/12/1985 72 3/8/1985
1986 TAM W-101   10/7/1985 6/12/1986 72 2/18/1986
1987 TAM W-101 8/20/1986 10/17/1986 6/15/1987 72 3/6/1987
1988 TAM W-101   9/17/1987 6/14/1988 72  
1989 TAM W-101 8/18/1988   6/20/1989 60  
1990 TAM W-101 8/29/1989 10/11/1989 6/13/1990 60  
1991 TAM W-101       60  
1992 TAM W-101 9/10/1991 9/30/1991 6/17/1992 75 2/3/1992
1993 Karl 9/16/1992 10/12/1992 6/17/1993 95 2/3/1993
1994 Karl 9/22/1993 9/27/1993 6/8/1994 95  
1995 Tonkawa 8/30/1994 9/29/1994 6/20/1995 90 2/24/1995
1996 Tonkawa 10/9/1995 10/10/1995 6/11/1996 70 3/13/1996
1997 Tonkawa 9/5/1996 10/3/1996 6/19/1997 70 2/17/1997
1998 Tonkawa 9/29/1997 10/3/1997 6/10/1998 68 1/30/1998
1999 Tonkawa 9/3/1998 10/13/1998 6/15/1999 68 2/15/1999
2000 Custer 9/5/1999 10/7/1999 7/6/2000 68 2/17/2000
2001 Custer   11/20/2000 6/12/2001    
2002 Custer   10/1/2001 3/3/2002    
2003 Custer   10/14/2002 6/23/2003    
2004 Custer   10/6/2003 6/16/2004    
2005 P2174   10/21/2004 6/7/2005    
2006 Endurance   1/7/2005 5/26/2006    
2007 Endurance   1/3/2006 6/8/2007    
2008 OKField   10/9/2007      
2009 OKField 9/16/2008 6/25/2008     3/9/2009
2010 GoLead 10/1/2009 3/3/2010 6/29/2010 90 2/22/2011
2011 Centerfield 9/1/2010 9/30/2010 6/9/2011    
2012 Endurance 9/15/2011 10/13/2011 6/8/2012 90 3/7/2012
2013 OK9935C 9/26/2012 11/16/2012 6/28/2013   3/11/2013
2014 Doublestop-CL 10/10/2013 10/22/2013 6/18/2014 75 3/21/2014
2015 Iba 9/26/2014 10/20/2014 6/8/2015 75 3/16/2015

Table 2.  Soil fertility treatment effects on wheat grain yields, Experiment #222, Stillwater, OK 1969-2000, and surface (0-6 inches) soil test results from 1995. 

 

 

            

Year Period

Soil Test (1995)

Treatment

 

 

69-78

79-88

89-98

99-00

  69-00

 

 

 

 

N

P2O5

K2O

 

 

 

 

pH

P

 OM

 

 

lb/ac

 

  bu/ac

ppm

 

 %

1.

0

60

40

25.3

19.2

12.8

14.9

18.3

5.85

50

2.27

2.

40

60

40

27.9

27.2

18.0

22.1

23.9

5.83

37

2.35

3.

80

60

40

28.5

28.6

21.8

30.4

26.4

5.50

34

2.27

4.

120

60

40

26.7

31.2

25.2

30.3

27.9

5.72

26

2.37

5.

80

0

40

25.0

27.2

23.3

32.9

25.7

5.59

14

2.20

6.

80

30

40

25.0

31.6

25.1

32.9

27.8

5.48

23

2.25

7.

80

90

40

29.1

28.4

20.5

27.1

25.8

5.54

50

2.30

8.

80

60

0

25.5

27.7

20.8

28.8

24.9

5.67

32

2.27

9.

80

60

80

27.3

29.9

22.4

30.1

26.7

5.55

38

2.24

10.

0

0

0

23.7

20.1

12.7

12.3

18.0

5.93

16

2.13

11.

120

90

80

27.6

30.7

26.3

34.7

28.7

5.73

40

2.27

12.

120

90

0

24.5

27.9

23.7

30.2

25.8

5.91

38

2.20

13.

80

60

40*

32.3

27.4

21.4

28.6

25.9

5.89

26

2.23

 

 

 

 

 

 

 

 

 

 

 

 

Mean

 

 

 

26.6

27.5

21.1

27.3

25.0

5.73

33

2.26

SED

 

 

 

3.1

2.8

2.0

4.8

2.7

0.15

8

0.11

CV, %

 

 

 

17

15

13

25

15

3.7

32

7

N, P2O5, and K2O applied as ammonium nitrate (34-0-0), triple superphosphate (0-46-0) and potassium chloride (0-0-60), respectively. *- K2O applied as sul-po-mag (0-0-22). SED standard error of the difference between two equally replicated means. CV  coefficient of variation.  pH 1:1 soil:water, P, Mehlich III extraction, OM = organic matter = OC*1.8+0.35 (Ranney, 1969)

Table 3.  Soil fertility treatment effects on wheat grain %N, Experiment #222, Stillwater, OK 1969-2000.

 

 

            

 

Year Period

Treatment

 

 

 

69-78

79-88

89-98

99-00

1969-2000

 

N

P2O5

K2O

 

 

 

 

 

 

lb/ac

         

% N

1.

0

60

40

1.99

2.01

2.30

2.22

2.12

2.

40

60

40

2.06

2.08

2.37

2.28

2.19

3.

80

60

40

2.14

2.26

2.69

2.46

2.40

4.

120

60

40

2.58

2.46

2.76

2.60

2.59

5.

80

0

40

2.33

2.39

2.51

2.47

2.40

6.

80

30

40

2.31

2.26

2.62

2.45

2.32

7.

80

90

40

2.24

2.34

2.62

2.41

2.36

8.

80

60

0

2.24

2.35

2.56

2.46

2.36

9.

80

60

80

2.23

2.27

2.56

2.48

2.31

10.

0

0

0

2.14

2.08

2.00

2.19

2.09

11.

120

90

80

2.55

2.43

2.75

2.71

2.51

12.

120

90

0

2.58

2.50

2.70

2.63

2.54

13.

80

60

40*

2.15

2.25

2.54

2.37

2.27

 

Mean

 

 

 

2.27

2.28

2.53

2.44

2.34

SED

 

 

 

0.17

0.12

0.15

0.11

0.14

CV, %

 

 

 

10

8

8

6

8

N, P2O5, and K2O applied as ammonium nitrate (34-0-0), triple superphosphate ( 0-46-0) and potassium chloride (0-0-60), respectively. *- K2O applied as sul-po-mag (0-0-22). SED standard error of the difference between two equally replicated means. CV  coefficient of variation.  pH 1:1 soil:water, P, Mehlich III extraction, OM = organic matter = OC*1.8+0.35 (Ranney, 1969)

<----- NORTH

View of Experiment #222 looking south east, April 2005


View of Experiment #222 looking south, January 2006

 

222, Stillwater Oklahoma 222, Stillwater, OK