Crop rotation diversity to improve water quality and increase soil health
Date
Authors
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Authors
Research Projects
Organizational Units
Journal Issue
Is Version Of
relationships.hasVersion
Series
The Symposium provides undergraduates from all academic disciplines with an opportunity to share their research with the university community and other guests through conference-style oral presentations. The Symposium represents part of a larger effort of Iowa State University to enhance, support, and celebrate undergraduate research activity.
Though coordinated by the University Honors Program, all undergraduate students are eligible and encouraged to participate in the Symposium. Undergraduates conducting research but not yet ready to present their work are encouraged to attend the Symposium to learn about the presentation process and students not currently involved in research are encouraged to attend the Symposium to learn about the broad range of undergraduate research activities that are taking place at ISU.
The first Symposium was held in April 2007. The 39 students who presented research and their mentors collectively represented all of ISU's Colleges: Agriculture and Life Sciences, Business, Design, Engineering, Human Sciences, Liberal Arts and Sciences, Veterinary Medicine, and the Graduate College. The event has grown to regularly include more than 100 students presenting on topics that span the broad range of disciplines studied at ISU.
Department
Abstract
Extended crop rotations that include a perennial forage crop are a key component of the Iowa Nutrient Reduction Strategy. In addition to reducing nitrate loss to Iowa waterways, extended crop rotations can also increase soil organic carbon content in surface and subsoils. Greater C storage in extended crop rotations may be attributed to greater root inputs, which can form organic matter more efficiently than aboveground inputs. The purpose of this study was to compare the biochemical composition of soil organic matter between an extended rotation (corn-corn-oat/alfalfa-alfalfa) and a simple rotation (corn-soybean). We hypothesized that the soil organic matter would reflect greater contribution of root inputs in the extended crop rotation. We collected soil samples from extended and simple crop rotations at four depths. We measured total fatty acids and fatty acid biomarkers that represent root and shoot compounds using pyrolysis-gas chromatography-mass spectrometry and extraction by cupric oxide. Results indicate fatty acids dominate subsoil carbon pools. Ongoing research using the cupric oxide method will quantify root and shoot biomarkers. High levels of root inputs are desirable because they promote resilience and stability of Iowa crop production.