Cluster Bean Irrigation x Nitrogen Trial (Split Plot, Simulated)

Simulated split-plot experiment on cluster bean (Cyamopsis tetragonoloba) with three irrigation levels in main plots and four nitrogen levels in sub-plots, in three replications.

Usage

clusterbean_spd

Format

A data frame with 36 rows and 7 variables:

rep: Factor, replication (R1-R3).
irrigation: Factor, main-plot irrigation level.
nitrogen: Factor, sub-plot nitrogen level (kg N/ha; foliar = additional 2% urea spray).
seed_yield: Seed yield (kg/ha).
water_use: Seasonal water use (mm).
wue: Water use efficiency (kg/ha per mm).
stover_yield: Stover yield (kg/ha).

Source

Simulated with data-raw/make_datasets.R (seed 2026). Not real experimental data.

Examples

data(clusterbean_spd)
anova_spd(clusterbean_spd, "seed_yield", "irrigation", "nitrogen", "rep")
#> 
#> ======================================================================
#>  SPLIT-PLOT TYPE DESIGN
#> ======================================================================
#>  Response     : seed_yield
#>  Design       : Split Plot Design
#>  Replications : 3
#>  Factors      : irrigation (3), nitrogen (4)
#> 
#>  Analysis of variance
#>               Source Df     Sum Sq   Mean Sq F value Pr(>F)    
#>  rep                  2    3154.39   1577.19   0.493 0.6437  NS
#>  irrigation           2 1057793.56 528896.78 165.238 0.0001 ***
#>  Error(a)             4   12803.28   3200.82                   
#>  nitrogen             3  209483.56  69827.85  89.389 0.0000 ***
#>  irrigation:nitrogen  6   15606.44   2601.07   3.330 0.0219   *
#>  Error(b)            18   14061.00    781.17                   
#>  Total               35 1312902.22                             
#>  Signif. codes: *** p < 0.001, ** p < 0.01, * p < 0.05, NS not significant
#> 
#>  Grand mean = 1123.778
#>   Error(a) [main]: df = 4, MS = 3200.8194, CV = 5.03%
#>   Error(b) [sub]: df = 18, MS = 781.1667, CV = 2.49%
#> 
#>  SEm, SEd and CD (alpha = 0.05)
#>  Comparison                                          SEm    SEd    CD     Error
#>  irrigation means                                    16.332 23.097 64.127 Ea   
#>  nitrogen means                                       9.316 13.175 27.681 Eb   
#>  irrigation levels at the same or different nitrogen 21.495 30.398 75.719 Ea+Eb
#>  nitrogen levels at the same irrigation              16.137 22.821 47.944 Eb   
#>  CD for comparisons mixing error terms uses the weighted t of Cochran and Cox.
#> 
#>  Means of irrigation (Fisher's LSD)
#>               Level    Mean Group
#>          I1 Rainfed  891.50     c
#>   I2 One irrigation 1179.83     b
#>  I3 Two irrigations 1300.00     a
#> 
#>  Means of nitrogen (Fisher's LSD)
#>       Level    Mean Group
#>          N0 1011.11     d
#>         N10 1102.22     c
#>         N20 1167.33     b
#>  N20+Foliar 1214.44     a
#> 
#>  Interaction means: irrigation x nitrogen
#>                         N0     N10  N20 N20+Foliar
#> I1 Rainfed          821.67  870.33  914     960.00
#> I2 One irrigation  1063.00 1145.67 1237    1273.67
#> I3 Two irrigations 1148.67 1290.67 1351    1409.67