Comprehensive information on Nitrogen Use Efficiency for cereal crop production, N use Efficiency

 

Research Methods in Agriculture

RCBD vs CRD

Split Plot (Tillage)


Contrasts (orthogonal contrast coefficients) (Table on line)
Contrasts for Unequal Treatment Spacing ( proc iml )

Run equally spaced rates in IML and see what it generates?

Treatment N rate Tillage
  lb/ac  
1 0 zero
2 50 zero
3 100 zero
4 150 zero
5 0 conv
6 50 conv
7 100 conv
8 150 conv

 

CRD   CRD   RCBD   RCBD-(split)  
Source of variation df Source of variation df Source of variation df Source of variation df
Total (4*8)-1 31 Total (4*8)-1 31 Total (4*8)-1 31 Total (4*8)-1 31
        block 3 block 3
treatment 7 treatment (8-1) 7 treatment (8-1) 7 tillage 1
Tillage 1         block*tillage 3 (a)
Nrate 3 nrate 3
nrate*tillage 3         nrate*tillage 3
error 24 error 24 error 21 error 18 (b)

RCBD versus CRD

RCBD-(no split)   zero till   conv. Till
Rep 1 1 8 3 2 5 4 7 6
Rep 2 6 2 7 8 3 1 5 4
Rep 3 3 6 1 4 8 5 2 7
Rep 4 7 4 2 5 6 8 3 1

 

RCBD (split block)   zero till   conv. Till
Rep 1 1 4 3 2 5 8 7 6
Rep 2 6 5 7 8 2 1 3 4
Rep 3 2 3 1 4 8 5 6 7
Rep 4 7 8 6 5 4 2 3 1
 
NEW Example: 3 N rates, 3 P rates, 2 levels of Tillage
Factorial Arrangement of Treatments vs "Factorial Experimental Design"
Needed when little is known about the interaction
Main Effects Levels Value Treatment Structure
N rates 3  0, 40, 80 Trt.  N rate P rate Legume
P rates 3 0, 10, 20 1 0 0 Y
Legume Cover 2 Y, N 2 40 0 Y
3 80 0 Y
Trt's 18 4 0 10 Y
5 40 10 Y
Danger of having too many levels 6 80 10 Y
7 0 20 Y
8 40 20 Y
9 80 20 Y
10 0 0 N
11 40 0 N
12 80 0 N
13 0 10 N
14 40 10 N
15 80 10 N
16 0 20 N
17 40 20 N
18 80 20 N

? Incomplete Factorial Treatment Structure  ?

data one;
input rep nrate legume $ yield preP;
cards;
1 0 L 16 16
1 50 L 25 13
1 100 L 29 9
1 150 L 35 8
1 0 NL 35 18
1 50 NL 35 6
1 100 NL 38 9
1 150 NL 39 19
2 0 L 20 22
2 50 L 26 23
2 100 L 30 28
2 150 L 32 25
2 0 NL 36 4
2 50 NL 36 8
2 100 NL 37 6
2 150 NL 40 7
3 0 L 17 8
3 50 L 22 19
3 100 L 25 48
3 150 L 29 22
3 0 NL 29 23
3 50 NL 34 25
3 100 NL 38 24
3 150 NL 40 18
proc print;
proc glm;
class rep legume nrate;
model yield = rep legume nrate legume*nrate;
contrast 'Nrate_lin' nrate -3 -1 1 3;
contrast 'Nrate_quad' nrate 1 -1 -1 1;
contrast 'legume*nrate_lin' legume*nrate -3 -1 1 3 3 1 -1 -3;
contrast 'legume*nrate_quad' legume*nrate 1 -1 -1 1 -1 1 1 -1;
means nrate legume legume*nrate;
run;

 
Legume (1)       No Legume(-1)      
0 50 100 150 0 50 100 150
 
linear
-3 -1 1 3 3 1 -1 -3
quadratic
1 -1 -1 1 -1 1 1 -1

 

interaction
Is it important to identify/discuss an interaction if it exists? (MSE's over sites?)
Antagonistic Interaction
Synergistic Interaction (did they respond the same)

model yield = rep legume rep*legume nrate nrate*legume;
test h = rep legume e = rep*legume;
means legume nrate nrate*legume;

Weaknesses of the split plot is the power in testing the difference in having a legume/or not because the rep*legume must be used as the error term.
----------------------------------------------------------------------------------------------

Factorial Arrangement of Treatments    (xx factorial design xx  )
   Tillage 2   N Rates 4  Factorial Treatment Structure = 2 * 4 = 8 total treatments
   All levels of N Rates evaluated over all levels of Tillage
   Factorial treatment structure allows for testing the interaction between the two ( or nrate*tillage )
     ?  Did N rates respond the same for the two different tillage systems  ?
     ?  This is the value of the factorial treatment structure  ?  BUT....  does it use up too many treatments

Efficient Design
4 reps df 3 reps df
Replications  4 Total (4*13)-1 51 (3*13)-1 38
Treatments  13 Rep  4 - 1 3  3 -1 2
Trt 13-1 12 13-1 12
Factorial Arrangement of Treatments Error 36 24
4 Rate
3 X-var. 12
1 check  13
RCBD Randomized Complete Block Design
CRD Completely Random Design

Image result for field spatial variability Image result for lake carl blackwell irrigation Related image


If the World were 100 People?

6.7 % hold college degree's


Linear Interaction

Contrast Program for Unequal Spacing

proc iml;
dens={0 100 600 1200}; **
p=orpol(dens);
t=nrow(p);
do i=1 to t;
  pr=abs(p[,i]);
  pr[rank(abs(p[,i]))]=abs(p[,i]);
  do j=t to 1 by -1;
    if pr[j] > 1.e-10 then scale=pr[j];
    if abs(p[j,i]) < 1.e-10 then p[j,i]=0;
  end;
  p[,i]=p[,i]/scale;
end;
print p;
run;

The only thing that needs to be changed is the trt values.

Output

Trt              P            lin              quad              cubic

0                1             -3.8           19.416667    -11

100           1             -3               1                    14.4

600           1             1                -40.66667     -4.4

1200         1             5.8             20.25             1

 

Experiment #222


data one;
input rep trt buac;
cards;

1 1 20.78765244
1 2 35.3777439
1 3 41.24329268
1 4 .
1 5 42.1839939
1 6 62.49207317
1 7 59.35640244
1 8 40.00746951
1 9 52.97439024
1 10 18.24222561
1 11 59.55929878
1 12 46.51859756
1 13 34.97195122
2 1 19.44115854
2 2 24.73490854
2 3 37.11158537
2 4 63.98612805
2 5 41.9257622
2 6 46.38948171
2 7 38.9929878
2 8 31.06158537
2 9 53.93353659
2 10 18.62957317
2 11 48.76890244
2 12 49.43292683
2 13 41.53841463
3 1 21.04588415
3 2 30.17621951
3 3 47.58841463
3 4 41.35
3 5 47.82820122
3 6 41.0035061
3 7 .
3 8 37.09314024
3 9 41.48307927
3 10 13.53871951
3 11 57.3089939
3 12 49.67271341
3 13 30.12088415
4 1 18.96158537
4 2 23.70198171
4 3 39.25121951
4 4 54.35777439
4 5 34.3632622
4 6 50.22606707
4 7 28.09192073
4 8 30.82179878
4 9 25.82317073
4 10 14.64542683
4 11 43.2722561
4 12 20.49253049
4 13 28.18414634
proc print;

proc
glm;
class rep trt;
model buac = rep trt;
means trt;

run;
proc mixed; class rep trt;
model buac = trt/ddfm=satterth;
random rep;
lsmeans trt/diff;
run;

quit;

Experiment #502
data one;
input rep trt buac gn;
cards;

1 1 29.88109756 1.970387936
1 2 32.0945122 1.914626837
1 3 53.95198171 1.851969123
1 4 50.35518293 1.821092963
1 5 71.93597561 1.963828087
1 6 80.78963415 2.209946632
1 7 88.8132622 2.672821283
1 8 70.27591463 2.546777248
1 9 73.31935976 2.218581676
1 10 83.27972561 2.157410383
1 11 73.04268293 2.675846577
1 12 97.94359756 2.663606405
1 13 71.38262195 .
1 14 76.63948171 2.125741243
2 1 22.6875 1.89458847
2 2 39.56478659 1.776858568
2 3 44.26829268 1.875116944
2 4 73.59603659 2.396464348
2 5 69.9992378 1.872512221
2 6 98.77362805 2.288419008
2 7 84.93978659 2.727875233
2 8 74.14939024 2.210676908
2 9 90.47332317 2.218745947
2 10 97.11356707 2.209470749
2 11 87.15320122 2.309687138
2 12 97.66692073 2.404773235
2 13 77.74618902 2.741914749
2 14 95.73018293 2.243032694
3 1 32.0945122 1.838460803
3 2 38.7347561 1.839552999
3 3 63.08231707 1.93320477
3 4 74.42606707 1.997364521
3 5 73.31935976 2.284578085
3 6 91.85670732 2.508112431
3 7 85.76981707 2.434265614
3 8 91.58003049 2.200210571
3 9 72.48932927 2.121579409
3 10 96.00685976 2.188293457
3 11 86.87652439 0.002466053
3 12 78.57621951 2.470286846
3 13 71.93597561 3.035435438
3 14 88.25990854 2.087241888
4 1 36.79801829 1.906446576
4 2 48.14176829 2.077796221
4 3 57.54878049 1.905510187
4 4 72.7660061 2.263180017
4 5 87.70655488 2.21556139
4 6 85.49314024 2.750952721
4 7 93.79344512 2.628683805
4 8 81.89634146 2.195582151
4 9 93.79344512 2.303760767
4 10 89.08993902 2.525472641
4 11 89.64329268 2.401524544
4 12 100.1570122 2.290474653
4 13 68.33917683 2.729845285
4 14 96.00685976 2.053695917
proc print;
data two; set one;
gnuptake = (buac*60)*(gn/100);
proc glm data = two;
class rep trt;
model buac gn gnuptake = rep trt;
contrast '1-5 versus 6,7' trt 1 1 1 1 1 -2.5 -2.5 0 0 0 0 0 0 0;
contrast '1-5 versus 6,7' trt 1 1 1 1 1 -2.5 -2.5;
contrast '2-5 versus 6,7' trt 0 1 1 1 1 -2 -2;
means trt;
lsmeans trt;
run;