Smallholder farming systems in Tanzania face challenges in achieving optimal efficiency, necessitating methodological improvements to better understand and enhance productivity. The review will synthesize existing literature on randomized field trials applied to smallholder farms, focusing on methodological strengths and weaknesses. Randomized field trials have shown mixed results; while some trials demonstrated significant efficiency gains (up to 20%), others failed to achieve expected outcomes due to variable soil conditions and inconsistent farmer participation. While randomized field trials can be effective, their success is contingent on precise experimental design and robust implementation strategies. Future research should prioritise detailed pre-trial planning and post-trial analysis to ensure consistent results across different farm systems. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.