The average soybean yield in Illinois in 2022 was 63 bushels/acre. However, the yield gap, a measure of the difference between record yield and average yield, is about 46 bushels/acre in Illinois and about 120 bushels/acre across the United States. Although seeding date, seeding rate, tillage practices, etc., significantly impact soybean yields on a wider geographical scale, soybean yields within a field can vary significantly even if the same seeding and management practices are followed. This within-farm spatial heterogeneity is one of the major factors limiting soybean farmers from maximizing soybean yields. Understanding this spatial heterogeneity is critical for site-specific management decisions, including the application of novel biologicals as a component of fertility management in soybean production. The objectives of the study include defining the spatial yield variation within a field, classifying the sites as high, medium, and low-yielding zones, determining the required seeding rates, and
economic evaluation of the yield from site-specific management and conventional soybean production for recommendation to the producers.

The objectives of the study include defining the spatial yield variation within a field, classifying the sites as high, medium, and low-yielding zones, determining the required seeding rates, and economic evaluation of the yield from site specific management and conventional soybean production for recommendation to the producers.

The study is expected to provide insights into the spatial variability in soil characteristics and soybean yields for soybean fields in southern Illinois. As within-field variability in soybean yield is a major constraint that prevents farmers from maximizing the production potential of soybean, comparing the yields from conventional soybean production, where the field is treated uniformly, to site-specific management, where the field is divided into variable zones for management will provide detailed information on the potential for filling the yield gap in Illinois. Further, the economic evaluation of these three production practices will provide information about the financial aspects of such site-specific management so that farmers can make judicious decisions on the management that best suits their crop production practices.

The study is expected to facilitate the development of recommendations for soybean producers in Illinois to maximize soybean production and reduce the yield gap.