Soil-Based Potential/Attainable Yields of Winter Wheat on the Base of Multi-Environment Trials Conducted in Poland

Attainable yields represent the yields that can be achieved under production conditions and are used to determine the exploitable yield gap. However, these yields are constrained by multiple factors, including soil properties, which vary at different spatial scales, even withing a single field. Thus, the attainable yields should be adjusted to specific soil units. This study uses results from multi-environment cultivar testing trials conducted by COBORU in Poland to estimate winter wheat attainable yields depending on arable land quality classes (ALQCs) and arable land suitability groups (ALSGs). The database comprises 10 years of observations from 18 locations and 156 experiments.. The results indicate a clear relationship between the scores assigned to particular ALQCs and ALSGs in 1981. In contrast, the relationship between the average scores assigned to ALQCs within ALSGs was weaker. Attainable yields were estimateddirectly based on experimental data, using the third quartile (Q3) of yields, for well-represented soil units, and regression analysis between Q3 yields and point scores for less-represented soil units. The results could be improved by using a more extensive dataset, particularly for underrepresentedsoils. The proposed method may be applied to estimate soil-adjusted attainable yields for other crops whose cultivars are tested by COBORU in multi-environment trials.