• Thanks so much for your answer, I also noticed one of the limitations of block randomization is they don't control for covariates unless combined with other methods like stratified randomization. so I will need to use adjustment in the analysis phase.

Bahar Ysr I would say yes. Block randomisation only control for whatever confounders captured within blocking. For example, if the blocking is based on the gradient of the land in an experiment of nitrogen fertiliser use and crop yield, I would still consider, other confounders, say, the amount of soil phosphorous in my analysis.