Soil water improvements with the long-term use of a winter rye cover crop

File

2016-SoilWaterImprovements.pdf (2.37 MB)

Date

2016-07-01

Authors

Basche, Andrea D.
Archontoulis, Sotirios V.
Jaynes, Dan B.
Sauer, Thomas J.
Parkin, Timothy B.
Miguez, Fernando E.

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Organizational Units

Agronomy

Organizational Unit

Iowa Nutrient Research Center

Organizational Unit

The Iowa Nutrient Research Center was established to pursue science-based approaches to evaluating the performance of current and emerging nutrient management practices and providing recommendations on practice implementation and development. Publications in this digital repository are products of INRC-funded research. The INRC is headquartered at Iowa State University and operates in collaboration with the University of Iowa and the University of Northern Iowa. Additional project information is available at: https://www.cals.iastate.edu/inrc/

Department

AgronomyIowa Nutrient Research Center

Abstract

The Midwestern United States, a region that produces one-third of maize and one-quarter of soybean grain globally, is projected to experience increasing rainfall variability. One approach to mitigate climate impacts is to utilize crop and soil management practices that enhance soil water storage and reduce the risks of flooding as well as drought-induced crop water stress. While some research indicates that a winter cover crop in maize-soybean rotations increases soil water availability, producers continue to be concerned that water use by cover crops will reduce water for a following cash crop. We analyzed continuous in-field soil water measurements from 2008 to 2014 at a Central Iowa research site that has included a winter rye cover crop in a maize-soybean rotation for thirteen years. This period of study included years in the top third of the wettest on record (2008, 2010, 2014) as well as drier years in the bottom third (2012, 2013). We found the cover crop treatment to have significantly higher soil water storage at the 0–30 cm depth from 2012 to 2014 when compared to the no cover crop treatment and in most years greater soil water content on individual days analyzed during the cash crop growing season. We further found that the cover crop significantly increased the field capacity water content by 10–11% and plant available water by 21–22%. Finally, in 2013 and 2014, we measured maize and soybean biomass every 2–3 weeks and did not see treatment differences in crop growth, leaf area or nitrogen uptake. Final crop yields were not statistically different between the cover and no cover crop treatment in any of the seven years of this analysis. This research indicates that the long-term use of a winter rye cover crop can improve soil water dynamics without sacrificing cash crop growth in maize-soybean crop rotations in the Midwestern United States.

Comments

This article is published as Basche, Andrea D., Thomas C. Kaspar, Sotirios V. Archontoulis, Dan B. Jaynes, Thomas J. Sauer, Timothy B. Parkin, and Fernando E. Miguez. "Soil water improvements with the long-term use of a winter rye cover crop." Agricultural Water Management 172 (2016): 40-50. doi:10.1016/j.agwat.2016.04.006. Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.

Keywords

Midwest Corn Belt, Cover crop, Soil water storage, Plant available water, Water content at field capacity, Plant growth