Dynamics of plant nutrient uptake as affected by biopore-associated root growth in arable subsoil

Soil biopores facilitate root growth in arable subsoil, thus improve resource acquisition potential. We aimed at determining the dynamic relationship between soil biopores and performance of two winter crops in field condition considering different biopore size classes, root characteristics and crop growth parameters. Chicory with dominant taproot system and tall fescue with limited taproots were grown for two consecutive years as precrops. Density of soil biopores larger than 2 mm and smaller than 2 mm in diameter was measured at 45 cm of soil depth. Destructive samplings were carried out for investigation on following barley and canola roots. Shoot biomass production, nutrient uptake and final yield of the following crops were determined throughout the growth seasons. Higher shares of large or small-sized bipoores were observed after chicory (23 %) or tall fescue (20 %) precrops, respectively. On average root diameter and root dry mass of following crops were greater by 11 and 15 % after chicory than tall fescue. At anthesis chicory-barley treatment accumulated 10 % more K in comparison to tall fescue-barley treatment. P uptake of canola was greater (7 %) after tall fescue compared with chicory at the stage of fruit development. Our results suggest that the subsoil heterogenization by altered soil biopores hold relevance for plant root growth and overall crop performance. However, the effects depended on biopore size classes, root characteristics and crop species. Development of direct methods that can quantify biopore-root-shoot processes, detailed investigation on drilosphere, root phenotyping for detection of the genetic variation in response to biopore systems have to be followed in the future.