Linking Soil and Water Quality with Crop Performance Across a Continuum of Tillage and Management Strategies: Enhancing Sustainability through...
Project Number: 5030-21610-002-54
Start Date: Mar 01, 2014
End Date: Jul 31, 2015
The hypothesis of this project is that systems using integrated methods of tillage, crop rotation, and cover cropping to promote crop health and productivity, suppress competitors, and minimize the impact on beneficial organisms and their environment will accrue long-term economic and environmental benefits. By evaluating across a continuum of experimental sites with different cropping histories and management practices, we will obtain: 1) An accurate assessment of the effect of different crop and cover crop sequences and tillage practices on soil health indicators, including organic matter, carbon sequestration, soil microbial, and microbial community structure and function; 2) A more thorough understanding of the effect of weeds, insects, and diseases under different management practices on crop yields and economic performance; 3) An assessment of the amount of reduction in nitrate leaching and potential climate change mitigation from different crop rotations and cover crop integration; and 4) Recommendations for methods to enhance ecosystem services and improve soil quality, which will increase economic returns and environmental sustainability for Iowa farmers by reducing costs of production and decreasing dependence on external sources of applied fertility and, potentially, lead to the procurement of carbon/emission credits.
The long-term goal of this project is to encourage transition to more ecologically-diverse methods of farming that preserve soil health and water quality. Three established experiments will be utilized in this project, each with a unique crop rotation and management history that will support comparisons across a continuum of conditions: 1) The Long-Term Agroecological Research (LTAR) Experiment, established in 1998 in Greenfield, Iowa, a long-term site comparing certified organic and conventional farming systems; 2) The USDA-ARS Organic Water Quality (OWQ) site in Boone, Iowa, a new experiment currently in its second year of crop production, comparing transitioning organic and conventional crop rotations and pasture systems; and 3) The Organic Reduced-Tillage (ORT) site in Boone, Iowa, in its sixth year comparing different cover crops and reduced tillage options.