Crop Rotation

 

What is crop rotation?

Crop rotation is a “system of growing different kinds of crops in recurrent succession on the same land” (Martin, Leonard, and Stamp, Principles of Field Crop Production, 1976). Thus, in the strictest sense, crop rotation is more than just changing crops from year to year based on current economic situations. Rather, it is a long-term plan for soil and farm management. The photo at right shows three crops in a corn-soybean-wheat/red clover rotation.

 

Why use crop rotation?

At the farm management level, crop rotations are used to diversify income, spread labor requirements throughout the year, and spread the crop loss risk associated with weather and pests across two or more crops. Rotations are also used to increase crop productivity by enhancing soil quality. In terms of soil management, crop rotations are used to:

  • Manage weed, insect, and disease pests
  • Reduce soil erosion by wind and water
  • Maintain or increase soil organic matter
  • Provide biologically fixed N when legumes are used in the rotation
  • Manage excess nutrients

The above factors all serve to increase crop yields, but there often is a yield increase to rotation above what can be accounted for by these factors. This response is called the “rotation effect” and has been documented for a variety of crops across multiple climates. The specific mechanism(s) causing this response has not been identified. Results from numerous studies in Corn Belt states indicate corn yield is about 10-15% higher in corn grown following soybean than corn grown following corn. Similarly, soybean yields following corn are typically 10-15% higher than when soybean follows soybean. Studies comparing the economics of crop rotation almost always conclude that profitability is enhanced by rotating crops. Duffy (2008) estimates that corn following soybean will cost 14% less per bushel to produce in 2009 than corn following corn. Producers using crop rotation will likely increase their profitability and promote the multifunctional benefits of crop diversity. Benefits to the ecosystem (soil quality, water quality) will likely increase as crop rotations are extended.

Info derived from: http://soilquality.org/practices/row_crop_rotations.html

rachelCrop Rotation