Organic Dry Bean Rotation Benefits.

In the Upper Midwest, edible legumes provide an opportunity for year-around access to sustainably grown, nutritious local foods for families and institutions.  Our objective is to promote diversification of organic cropping systems with edible dry beans as a means to provide valuable ecosystem services and generate a sustainable agricultural economy.  As a first step in this process, we are conducting a rotation experiment comparing the agroecological value of edible beans grown in rotation. From 2010 to 2015, this replicated 3-year rotational experiment has been situated on certified organic land at the Elwell Ecological Station at Lamberton and Carmen Fernholz’ farm in Madison, WI, as well as UMN research sites in Becker and Rosemount.  Establishment, weed competition, and nitrogen carryover potential have been studied pertaining to the effects of either corn or alfalfa in the first year.  In the second year, six different market classes of beans were evaluated for a number of different performance characteristics including weed competitiveness, yield, and their nitrogen contribution to the following wheat crop.  Further, variable rates of organic nitrogen were applied to assess the fertilizer N equivalency of dry beans on the subsequent wheat yield.  Preliminary data from 2014 suggests that dry bean yields are higher following alfalfa than corn, with dry bean yields following corn making up only 60-85% of beans following alfalfa.  Weed biomass data, also from 2014, indicates that weeds were twice as high in the bean fields that followed corn than alfalfa.  Wheat yields have shown mixed results thus far, with potential fertilizer carryover from applications on corn fields.  The final results of this multi-year trial will be compiled this summer post wheat harvest.  Coupled with our other dry bean trials, we hope to increase understanding and application of the economics and rotation benefits of producing alternative protein crops.