Integrating Organic Soybean Production following Conservation Reserve Program (CRP) Land into Sustainable Farming Systems

Integrating Organic Soybean Production following Conservation Reserve Program (CRP) Land into Sustainable Farming Systems

Summary

Objectives of this project include:

1) Establish plots dedicated to organic farming research on CRP land,

2) Implement production and management regimes for opening CRP land and for weed control on conventional and organic systems on CRP land,

3) Evaluate the biological and economic outcomes of the different systems; and

4) Promulgate technology transfer through demonstration/field days and publications for area farmers and agricultural professionals.

Organic farming has increased to a $6 billion industry in the U.S. and continues to expand approximately 20 percent annually. With the increasing interest in conversion to certified organic production, land grant institutions face numerous requests for scientifically validated research on organic production practices and their underlying ecological mechanisms. The current 20 to 400 percent market premium for certified organic products has served as a powerful incentive for producers desiring extra income in increasingly stringent markets. Farmers are able to by-pass the three-year transition period between chemical and certified organic designation on Conservation Reserve Program (CRP) land that has not been sprayed. Because of current lucrative markets (ranging from 250 to 400 percent premiums above conventional soybeans), the Organic Agriculture Program office at Iowa State University receives an average of 10 communications per week requesting information on organic soybeans and recommended practices for CRP land.

There are many similarities between the intent of the CRP and the philosophy behind organic farming: both systems strive to preserve soil structure and quality, and protect waterways from silting and runoff. Several factors will impact the success of an organic farming operation on CRP land, including tillage practices, the use of cover crops, weed management, and proper crop rotations. The initial two years represent a critical period for most farmers to reach a decision regarding the feasibility of organic production for their farm. The Leopold Center for Sustainable Agriculture has also provided support for this project.

Research sites will be located at the Iowa State University McNay Research and Demonstration Farm in Chariton, Iowa (southern) and at two on-farm sites in Clinton (eastern) and Brooklyn (central), Iowa. Land on these farms has been in CRP for 5 to 10 years. Two rotations, three tillage operations and two methods of weed control under organic and conventional management will be evaluated at the McNay Farm. Goals at this site include determining which crop performs the best in terms of yields and pest status (weeds, insects and diseases developing with each system).

We will determine which tillage method fits best with each weed control method to allow for maximal soil/plant protection and yields in the first two years. Main plots will consist of conventional and organic corn, soybeans and oats on land treated with one of three fall tillage methods for opening CRP land: Treatment 1 = standard moldboard plow, Treatment 2 = Kverneland inversion plow, Treatment 3 = Rotovator. Subplots will consist of two weed control practices: mechanical cultivation and propane flame-burning/cultivation. The goal of the on-farm research will be a comparison of time of tillage and use of cover crops in certified organic production. Main treatments will consist of fall- vs. spring-plowed CRP land. Subplots will consist of winter rye vs. no rye cover. These treatments reflect existing practices on midwestern organic farms, which have not been subjected to scientific evaluation in replicated trials.

A core set of measurements will be taken at each site, including crop plant productivity, soil health indicators, weed species distribution and abundance, insect damage, predator/parasite abundance and climatic characteristics. Of particular importance will be the quantification of soil health indicators in the different systems, including soil organic matter, nitrogen, carbon and microbial biomass. Economic analysis will include detailed accounting of total costs for inputs, and subsequent yields and selling price of organic vs. conventional crops. Nutrient and financial budgets will be developed for each system.

So far, Results from the McNay farm are very promising. All organic soybeans yielded well—above the county average for both 1999 and 2000. While plant populations were reduced by tillage, there was no significant difference among tillage treatments in final stand counts. Though grass weeds increased significantly early in the season, weed populations were not significantly different at the end of the 1999 season. Field days will be held once a year at the Experiment Station and on-farm sites. Wherever possible, field days and results from these trials will be incorporated in SARE Professional Development Programs in Iowa. Results of these trials will be reported at all organic farming conferences in Iowa and at scientific conferences as well.