Summary Content
This project established a multi-site experiment that helped assess attainable yield, attainable water productivity, as well as failures in nutrient and disease management for different representative environments across Minnesota. This information had not been previously available and provided further insight on location-specific management.
The questions we aimed to answer were: What was our attainable yield? Was there a yield gap that could be filled by soybean management? Could we identify the causes? The goal of the project was to benchmark attainable yield and to identify key management practices explaining the gap between farmers’ actual yield and the attainable yield as determined by climate, soil, and genetics across different environments in Minnesota.
The network consisted of 10 field experiments conducted in environments with contrasting soil and climatic characteristics. All the experiments were carried out under rainfed conditions. The trials were set up in farm fields planted by the farmers according to their usual management practices. Variety, planting date, plant density, and row spacing were chosen by the farmer. At each site, the farmer-adopted fertility and disease management programs were compared against a full nutrition treatment and against a full nutrition plus fungicide treatment.
Treatment factors are presented in the table below:
Findings
Soybean grain yield registered for the different treatments at each field during the 2024 season is presented in Figure 1. In general, we found no effect of any intensification treatment, except in Hector, where yield increased by 15% compared to the farmer management under the Nutrition and Full (Nutrition + Fungicide) treatments. Therefore, under the assessed climatic conditions, almost all the fields produced very close to the attainable yield.
To increase profitably and sustainability of Minnesota soybean farmers during challenging times, it is important to begin by estimating the attainable yield across state and then compare it with the actual yield that farmers logged in their yield monitors. Is there room for intensification? We assessed attainable yield data from the 20 fields evaluated during the last two seasons. Overall, the yield under farmer management did not differ from the estimated attainable yield (no significant yield gap). This could indicate that the farmer’s objective yield might be set above the maximum attainable yield and that the focus should instead be on saving inputs while maintaining yield, thereby increasing profits.
Well-calibrated crop simulation models, coupled with high-quality weather, soil, and crop management data, could be used to upscale this analysis on attainable yield to major producing areas that share similar weather and soil characteristics. This framework would have allowed us to map a benchmark to evaluate the level of intensification in our farms – supporting decisions on reducing, maintaining, or increasing the amounts of inputs in different fields.
