Enhancing food security for smallholder farmers amidst challenging climatic conditions requires accurate quantification of agricultural production. However, there are increasing debates on the weaknesses of commonly used yield estimation approaches in smallholder production systems. There is also a limited understanding of the implications of methodological choice of different yield estimation approaches at varying scales in diverse production systems. As such, smallholder farming systems in sub-Saharan Africa (SSA) have been characterized with substantial crop yield variability which is persistent even within the same agro-ecological zones. Moreover, broad comparisons for regional and national agricultural productivity have often formed the basis of certain misconceptions about crop productivity across a wide diversity of production systems, each with its own peculiarities and oddities. Additionally, the key factors influencing accuracy and reliability of yield data are still not well understood and are often overlooked when estimating yield in both small and large-scale surveys. This review provides an in-depth comparative analysis of trade-offs and sources of error in commonly applied yield estimation approaches in SSA production systems. Also, here for the first time, we collectively discuss the key factors that impact accuracy and reliability of yield data in diverse production systems in sub-Saharan Africa. Our review provides useful insights for standardizing on-farm yield measurement approaches and benchmarking crop production in smallholder production systems, a prerequisite for recommendations and decision-making in agricultural research. Improving the measurement of yield data will increase the understanding of diverse smallholder production systems and consequentially improve the targeting of productivity-enhancing interventions.

Accurate measurement of crop yields in smallholder farming systems, especially in sub-Saharan Africa, is a pressing issue for agricultural research. Despite the widespread use of crop yield data in farm research and policymaking, there are significant challenges in generating valuable and accurate data regarding quality, quantity, and reliability, particularly in sub-Saharan African agriculture. The methodological choice of different yield estimation approaches and their suitability for context-specific settings is also not well understood. This review addresses these gaps by providing a comprehensive and qualitative overview of widely applied yield estimation approaches for grains in smallholder agriculture and analysing their trade-offs and suitability for context-specific farming systems. Additionally, key factors influencing the accuracy and variability of yield estimates in smallholder farms are discussed. By analysing these factors, this paper provides valuable insights for establishing benchmarks in crop production within smallholder farming systems, which is essential for making informed recommendations and decisions in agricultural research. The findings of this review are crucial for informing agricultural research and guiding decision-making, thereby contributing to the improvement of smallholder farming systems in sub-Saharan Africa.