Preceding-crop-associated differences in accumulation dynamics of multiple nutrients in Swedish winter wheat (Triticum aestivum L.)

Context and Objective Nutrient use efficiency depends on factors including soil nutrients, and the corresponding root system architecture (RSA) adaptations. The preceding crop (precrop) can alter soil nutrient levels, affecting crop nutrient accumulation and RSA, with further variation by region and variety. This study investigated how region, year, precrop and genotype were associated with nutrient uptake, RSA, and yield in on-farm winter wheat trials. Methods Field trials of winter wheat were conducted in three Swedish regions over four years in paired on-farm fields. In each region–year combination, one field followed a cereal precrop and one a dicot precrop. RSA and nutrient concentrations were measured, then scaling exponents and hypervolumes were calculated to assess nutrient profiles. Results and Conclusions Nutrient profiles of wheat differed consistently between fields following cereal and dicot precrops. Fields following dicot precrops had higher calcium (Ca) and magnesium (Mg) concentrations, whereas phosphorus (P) concentration was higher after cereal precrops. Potassium (K) accounted for 46% of the total normalised random-forest importance for variation in Jaccard similarity among four-dimensional nutrient hypervolumes and strongly influenced element scaling exponents. Higher K concentrations correlated with nodal root number after an oilseed rape precrop and with yield after a wheat precrop. Nodal root angle also strongly correlated with P concentrations, with the strength and direction of these correlations varying by growth stage & precrop. Significance The findings emphasise the importance of taking environmental and management factors - particularly crop rotation, regional variations, and field management history – into consideration to optimise nutrient use efficiency and improve wheat yield over diverse regions and cropping practices. Understanding these interactions can guide agricultural practices and allow for better breeding for RSA traits.