The Crop Sequence Calculator (version 3.1) is a user-friendly program that runs directly from a CD-ROM, eliminating the need for additional disk space or installation procedures. The program has been expanded to provide crop sequence information on two research projects (Phase II and Phase III) conducted from 1998 through 2005 at the Northern Great Plains Research Laboratory. Information on crop production, economics, plant diseases, weeds, water use, and surface soil properties has been expanded to aid producers in their evaluation of management risks associated with different crop sequences. The user can select which group of crops are of most interest in either Phase II (above-average precipitation and a higher percentage of cool-season crops) or Phase III (below-average precipitation and a higher percentage of warm-season crops). Then choose the residue crop and expected crop from pull-down menus to view estimated yields and summary statements about production economics, disease, soil water, weeds, and surface soil properties. Information on 16 crops are covered by the two research projects, four of which were common to both. Photographs of weeds and insects along with additional resource information (e.g. many related Internet links) are also included.

Version 3.1 contains the previous version, 3.0, and adds new information gathered from additional cropping sequence research, as well as supplemental information related to use of annual crops as cover crops.