Topographic and Soil Influences on Root Productivity of Three Bioenergy Cropping Systems

by Christina Whalen

Root production in plants plays a vital role in ecosystem carbon, nutrient, and water cycling, but researchers have not made much progress in further understanding this issue. It’s important to understand the impacts of environmental conditions on root production because it aids in the development of a sustainable bioeconomy. However, scaling root productivity estimates for cropping systems beyond plot scales poses a great challenge to researchers. Whether the bioenergy plants are annual or perennial influences the biogeochemical cycling and the ecological benefit of the systems. The foundation of the study is based on previous research of the response of root growth to variations in soil properties at multiple spatial scales. Roots of plants generally respond to different soil types by growing into nutrient patches, but this depends on the species and nutrient demands or limitations. Ontl et al. measured the response of root productivity of three different bioenergy cropping systems across a topographic gradient with variation in typical agroecosystem soil conditions. The hypothesis is that root dynamics would vary by cropping system and position of the landscape across a hillslope. If landscape alone was not a good enough indicator, they predicted that root productivity would be related to differences in soil. Continue reading