Improving Soil Health and Weed Control When Transitioning to Organic Production.

The three year transitional period from conventional to organic row cropping can be the most important and the most challenging time for an organic farmer. Maintaining or improving weed control and soil health is never more vital than during this time, but it is also the period in which a new organic farmer is likely to have the least experience with organic practices. The overall goal of this research project is to improve the competitiveness of transitional organic grain crop producers by documenting critical information on cropping systems that will help maintain or increase productivity, suppress weeds and build soil health. This was done by comparing seven different rotational and tillage systems including utilizing three years of continual cover crops, conventionally tilled and no-till corn/soybean and sorghum/soybean rotations, two years of cover crops with hay removal followed by corn, and a cover crop/wheat/soybean rotation. After two years of study, we have found improved soil health parameters and improved weed control in the cover crop only plots and increased weed pressure and greatly reduced yields in the no-till plots. Conventionally tilled plots have improved weed control but have decreased soil health levels. Organic no-till has been found to be very challenging and we believe that further research needs to be done on mechanical methods of controlling mid and late season weeds that come up through the cover crop mulch. Sorghum-sudangrass has proven to be an excellent soil health builder while nearly eliminating weed pressure. These results indicate that using cover crops as much as possible during the three year transition to organic may have long-reaching effects on improving yields after organic certification is achieved.