Agroecological Determinants of Yield Performance in Mid-Early Potato Varieties: Evidence from Multi-Location Trials in Poland

Potatoes are a strategic crop in Poland, particularly important for agriculture in the southern and southeastern parts of the country. Environmental variability makes assessing yield stability and quality traits of varieties crucial for food security. Research Objective and Methodology: This three-year field study (2021–2023) aimed to comprehensively assess the yield stability and quality traits of mid-early potato varieties. The research was conducted in four pedologically diverse locations (rendzinas, brown soils, alluvial soils, and pseudopodzolic soils), according to the COBORU methodology. Key yield parameters (total and marketable tuber yield) and quality traits (dry-matter and starch content and yield) were analyzed. Interregional stability was also assessed. The environmental characteristics were supplemented with detailed analyses of soil physicochemical and biological properties, monitoring of agroclimatic parameters, and an assessment of the impact of geographical location. The collected data was subjected to advanced statistical analyses (ANOVA, correlations, descriptive statistics). Results analyses revealed significant yield variation across soil types, with the highest yields on alluvial soils and the lowest on pseudopodzolic soils. Geographic location significantly influenced yield stability, highlighting the role of local factors. Strong correlations were also found between soil properties and starch content (r = 0.61–0.73), indicating a key influence of the soil matrix on tuber quality. Conclusions and Recommendations: This study provides practical recommendations for selecting potato varieties adapted to specific soil types, precision fertilization strategies, and climate-change-adaptation protocols. Further research should focus on the impact of extreme weather events, optimized water management, and the use of precision agriculture.