The quality of meta-analyses in agricultural sustainability has been increasing, but weaknesses persist

Meta-analyses (MAs) are needed to inform agricultural policies on sustainable farming practices (FPs). This study assesses the quality against established criteria of 570 MAs published from 2000-2023 and included in the recently published "JRC-Farming Practices Evidence Library". We find that average MA quality significantly improved (p < 0.001) over time. However, about two-thirds of the assessments showed deficiencies in at least four areas, notably study selection and publication bias reporting. MAs related to animal husbandry, manure management, and those synthesizing modelling-derived outcomes demonstrated particularly low quality. Less than 40% of MAs provided accessible original data, limiting reproducibility and re-use. These shortcomings may hinder the full potential of MAs to support evidence-based policy. We propose recommendations to promote FAIR data sharing, enhance awareness, and encourage greater transparency in reporting, which a needed to strengthen the role of MAs in agricultural sustainability.