News Release

From 2002-2005, a team of researchers at the USDA-ARS Northern Great Plains Research Laboratory in Mandan, North Dakota investigated crop sequencing effects of 10 crops in a region known for its variable climate. The researchers report their findings as a series of six papers in the July-August 2007 issue of Agronomy Journal. The results from the study were originally presented at the 2005 ASA-CSSA-SSSA annual meeting.

Because crop performance is greatly influenced by the sequence in which crops are grown, USDA researchers set out to explore the short-term effects of sequencing a variety of different crops grown throughout the Great Plains. Over a three-year period, USDA researchers used a unique crop by crop-residue matrix design to evaluate the effects of 100 crop sequences on crop production, plant diseases, soil residue coverage, and soil water depletion.

“The crop by crop-residue matrix approach along with the multidisciplinary research team effort enhanced evaluation of crop interactions that may otherwise be overlooked in crop sequence research,” said Don Tanaka, project leader for the USDA research effort.

In the six papers presented by the USDA highlight:

• Crops and crop sequences that optimize precipitation-use efficiency for maximum productivity
• Ways to decrease production risks from plant diseases in diverse cropping systems
• How to maintain an amount of crop residue under no-till to optimize agronomic benefits while minimizing negative effects
• How to most effectively sequence crops in semiarid environments while maximizing use of available soil water
• The value of understanding crop sequencing effects for achieving agroecosystem sustainability

While the dynamic cropping system studies centered at the USDA-ARS Northern Plains Research Laboratory have helped scientists to better understand the short-term effects of crop sequencing, researchers say there is a lot to learn about how different crop sequences affect the many factors that influence agronomic and environmental outcomes within cropping systems.

“Such short-term research efforts can help identify crop sequence ‘synergisms’ and ‘antagonisms,’ thereby providing the necessary foundation for developing strategies to sequence crops over a longer period of time,” researchers write.

The research team at the USDA-ARS Northern Great Plains Research Laboratory is actively working to translate their research findings for use by agriculturists through an update of the Crop Sequence Calculator, an interactive computer program designed to assess crop sequencing options for optimizing economic, agronomic, and environmental goals within dryland cropping systems.