Are there temporal trends in root architecture and soil aggregation for Hordeum vulgare breeding lines?

The crucial role of roots in mediating agricultural sustainability and food security is becoming more widely appreciated. Here we tested the potential impact of barley (Hordeum vulgare L.) breeding (German germplasm) on root architecture and possible ripple-on effects on soil aggregation. In a greenhouse study, we tested two barley breeding lines. We focused on very fine (<0.2 mm) and fine (0.2-1 mm) roots. Soil structure was measured as percentage of water-stable macroaggregates and aggregate size distribution from dry-sieving. Breeding of barley reduced very fine root length of one of the tested lines but had no effect on our measures of soil structure. Our results indicate that breeding practices need not lead to an overall decline in root length. While we did not find that reduced very fine root length propagated to negative effects on soil structure parameters, additional studies should address this important aspect in other crop lineages and soils. (C) 2013 Elsevier B.V. All rights reserved.