Is one year enough? A commentary on field experiment duration in agricultural research

Context

While multi-year field experiments remain a cornerstone of agricultural research, their requirement warrants critical examination.

Objective

This perspective analyses the scientific rationale behind multi-year experiment expectations and proposes a framework for determining appropriate experimental duration based on research objectives, mechanistic understanding and environmental dependencies.

Results and conclusions

Field experiments offer distinct advantages over laboratory studies by capturing environmental complexity, including weather variations, soil biological dynamics, pest pressures, and the effects across spatial scales. Multi-year experiments enhance research robustness through increased reliability, better understanding of treatment effects under varying conditions, and greater statistical power. However, significant limitations include increased costs and resource demands, which can create barriers particularly for researchers in low- and middle-income countries, early career researchers, and those working on time-sensitive agricultural issues. We argue that certain research contexts (some of which are the same for short-term mesocosm and incubation scale experiments), such as mechanistic studies with clear process understanding, innovative technology validation, or time-sensitive investigations (including double and triple cropping systems), should warrant acceptance of single-year experiments when accompanied by robust supporting evidence and comprehensive metadata.

Significance

A more flexible and nuanced approach to determining study duration could better serve agricultural science advancement while maintaining research rigour, especially for studies combining detailed mechanistic investigations with field validation, that could, and should, be systematically integrated into future meta-analyses.