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United States Department of Agriculture

Agricultural Research Service

Research Project: WATER QUALITY IMPROVEMENT FROM MANAGEMENT PRACTICES IN AGRICULTURAL WATERSHEDS Title: Modeling the long-term effect of winter cover crops on nitrate transport in artificially drained fields across the Midwest U.S.

Authors
item Malone, Robert
item Jaynes, Dan
item Kaspar, Thomas
item Thorp, Kelly
item Ma, Liwang
item James, David
item Kladivko, Eileen -
item Singer, Jeremy

Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: January 8, 2014
Publication Date: N/A

Technical Abstract: A fall-planted cover crop is a management practice with multiple benefits including reducing nitrate losses from artificially drained fields. We used the Root Zone Water Quality Model (RZWQM) to simulate the impact of a cereal rye cover crop on reducing nitrate losses from drained fields across five states in the Midwest. Within the five states, we estimate that a minimum of 3.6 million ha of drained land used to grow corn in rotation with soybean are immediately suitable for cover crops, because they are currently in no-till or ridge-till or are not tilled in the fall. An additional 3 million ha would be suitable, but delaying tillage until spring on these lands would be more difficult to integrate into the current farming systems. Considering the estimated area within the five states that drains to the Mississippi River, cover crops have the potential to reduce nitrate losses from drained fields by 89 million kg yr-1, or about 11% of the total nitrate load in the Mississippi River. We estimate that the cost per kg of nitrate removed in drainage water with cover crops would be from US$3.87 to $10.33 (kg-N)-1, a cost quite competitive with other management practices for reducing nitrate loads in surface waters.

Last Modified: 9/1/2014
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