I am struggling with the formulation in lme of a generalize randomized block design(GRBD's) with subsampling. The experiment consists of 2 strips, each represents treatment (4years/2years- under crop rotation). Each strip consists of 3 blocks, in each block 4 experimental plots, 2 plots for each of 2 additional treatments (mix crop/non-mix crop). In each plot, I took 3 samples for decomposition rate, some samples are missing (NA's). I want to compare between the 4 treatments (4years-mix; 4years-nonmix; 2years-mix; 2years-nonmix) performance.
My initial model looks like this:
lme(decomposed_fraction ~ treatment, random= ~1|block/plot/repetition, data=Dt, na.action=na.omit)
However, I'm not sure whether this model reflect correctly the GRBD's analysis and take in consideration correctly the experimental design. Any suggestions and explanations are welcome!
Thanks, Bents